Wally Rippel (BS '68), Electrical Engineer
December 9, 16, 2021 and January 3, 2022
The electric cars that make up an ever-increasing portion of cars on the road owe their origins in large part to a VW Bus putting around the Caltech campus, and driving to victory cross country in the world's first Great Electric Car Race. The man behind this achievement is Wally Rippel, who as a Caltech undergrad ripped the gas motor out of the Bus, installed batteries, and proceeded to beat MIT in a race to opposite campuses.
Born in Los Angeles and fully ensconced in Southern California car culture, Rippel saw the development of electric cars as both an environmental opportunity to reduce air pollution, and an engineering opportunity to build cars that were faster and better than their gas-powered counterparts.
At every juncture of the saga of EV history, Rippel was present at the creation. For Aerovironment, he contributed to the winning design in the solar-powered race in Australia; for GM he helped to make sure that the Impact concept and EV1 were reliable, "real world" cars that were also great fun to drive; for AC Propulsion, he helped to transform a shoestring startup to the creator of the tZero sports car; and for Tesla, he provided key expertise long before the company was viable, let alone dominant in the industry.
Always keen to the next big development, Rippel is currently working at the interface of next-generation battery technology and to make the electric grid smarter and more resilient.
DAVID ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Thursday, December 9th, 2021. I am so happy to be here with Wally Rippel. Wally, thank you so much for joining me.
WALLY RIPPEL: My pleasure.
ZIERLER: To start, would you tell me please either your current or most recent title and institutional affiliation?
RIPPEL: I retired from AC Propulsion, a company that I cofounded with Alan Cocconi. Before that, I worked at Tesla, and I was kicked out. That's an interesting story. [laughs]
ZIERLER: When did you retire from AC Propulsion?
ZIERLER: In the intervening years, have you been enjoying a true retirement? Are you consulting? Are you active in any projects?
RIPPEL: I've been working with my son. We've formed a company called Enure. It's kind of a legal term. When things turn out in the favor of one party, it "enures" in their favor, so we thought that would be a good name. The thing we're working on is what we call megawatt charging. I've done some stuff with improvements on motors, better heat transfer. In terms of where I think the market is going, the high-rate charging seems to be an appropriate thing. There's an immediate market for megawatt charging for trucks as trucks are going to be coming online electric—the Tesla vehicle and others, a semi-truck that they're working on. These vehicles will store between 500 and 1,000 kilowatt hours, so charging at a million watts still is as one-hour recharge. [laughs] It's not necessarily the fastest charging. The batteries are going to continue improving in terms of their charge acceptance. My prediction is that in four or five years, passenger cars will be able to be charged at the megawatt rate. That means a car with a 100-kilowatt-hour battery like the Tesla Model S, you could charge that then in one tenth of an hour or six minutes.
ZIERLER: That's like a trip to the gas station.
RIPPEL: Yeah. This is the one remaining weaknesses with electric vehicles, is recharge. The other thing is initial cost, and I think both of those will in the next five years or so improve significantly. I'm trying to position myself and with my son, so that we'll have something of value as that time comes around.
ZIERLER: Is this all in the context of lithium ion batteries?
RIPPEL: Yes. Lithium ion batteries are what we have right now, and we'll probably have lithium ion and derivatives of lithium ion for a number of years to come. At some point, I want to talk a little bit about batteries. It's something I've thought about a lot. When I first got involved here with electric vehicles, I started thinking about batteries. It has been a messy field. A lot of people don't want to work in it. I look forward to talking about that. The anticipation is that lithium and variations of lithium will be around for at least another five years. I'm hoping that we'll see a breakthrough, and I'll talk about that later.
ZIERLER: Just to get a sense of where you're coming from in all of these things, are you a scientist? Are you an engineer? Are you a businessperson? Where are you on that spectrum?
RIPPEL: [laughs] I was going to say—an imposter! [laughs] My life's work has been in power electronics. When I was in school, both here and at Cornell University, power electronics really wasn't taught, so I picked that up through work and through the interest. That's true for a lot of people, especially older people like myself. That's why I joke and say I'm an imposter. I learned a little bit about motor design. I took a couple of classes at Cornell University that I didn't learn that much from. Most of what I learned was through the experience of engineering and doing stuff.
ZIERLER: Was there a graduate program in power electronics at Cornell?
RIPPEL: No, not at that time. And it's interesting, Caltech had a program under Professors [Slobodan] Ćuk and [R.David] Middlebrook dealing with power electronics, and that was terminated because of lack of interest. When I last saw the class, most of the students were foreign nationals in the class. I think things have changed substantially from when I was a student here in the 1960s.
ZIERLER: And the field, if you can explain, what is power electronics?
RIPPEL: Power electronics is where electronics has muscle. Inverters are examples of power electronics, where you take the direct current from a battery and change it to alternating current so you can operate an AC motor, like an induction motor, or a permanent magnet motor, which also requires AC. By the way, power electronics is, from my point and many people, what differentiates the modern electric car from things previous, is the use of power electronics, where the DC power is being converted electronically into AC, where there are electronic controls to do that, as opposed to the electric cars of the early 1900s, which were truly electrical, where you had the things like motors and contactors and variable resisters and things like that, but nothing involving electronics. It didn't exist, then.
ZIERLER: That reminds me, where is the term "electric" and "electrical" significantly different, and when is it just semantics?
RIPPEL: Electric and electrical I think are pretty closely tied. But electronic differentiates from electrical. When we look at the conventional grid, with transformers and three-phase power distribution lines, we think of that as electrical. That used to be the conventional electrical engineering before World War II. You learned about those things, about machines and transformers and distribution and so on. Then with World War II came electronics for communication and radar and things like that. Dr. Lee DuBridge had been involved with that development. There was a shift away from the conventional electrical engineering to what you could call electronic engineering. It was still called electrical engineering, but it involved now semiconductors later on, and earlier, vacuum tubes.
ZIERLER: The work with your son, is he also in power electronics?
RIPPEL: He is self-educated. He elected not to go to college. He wanted to work with me. It's kind of strange. I let him do this. But he has picked up a certain amount of engineering and he's interested in the business side, and he does the business side much more than I do. He has a natural instinct for that. We work pretty much as a team. He has a sense of art, also, so that where it comes to aesthetics and things like that, he has inputs which I probably would be weak on.
ZIERLER: How well-developed is the company at this point? Are there other employees?
RIPPEL: It's really just the two of us at this point. We're still putting stuff together to go on the road and raise capital. What we have done is demonstrated some new technology. Basically it's built around an invention that I have, which is a power electronics invention, which allows you to do the power conversion at these high power levels more cost-effectively. With the vision that that may parlay into recharge stations across the country, there can be a significant business opportunity there.
ZIERLER: Now, is this out of your garage? Are you renting commercial space?
RIPPEL: It's really out of my garage. What I did in 1985—
ZIERLER: It's like Hewlett Packard in the early days!
RIPPEL: Yeah, yeah. In 1985, I added to my garage, so it's a garage-plus. [laughs] I've got a combination lab and office which I built myself in 1985. At that time, I was working at JPL. So I've been in the family for a good time.
ZIERLER: What are some of the products or clients that Enure would go for?
RIPPEL: People like chargeONE and other companies doing recharge. The question will be, do we supply components, or do we supply systems, or ultimately do we provide complete recharge facilities? A lot of that will be dependent on the type of investment we are able to get.
EVs and Smart Grids
ZIERLER: At a very broad level, where is the EV infrastructure today and where do you want to see it go in the future? Of course, the gorilla in the room here is where is Elon Musk and his proprietary technology in all of this?
RIPPEL: First, I'm going to answer in reverse order. Tesla does not have any magic sauce that I know of. They've done a good job of engineering. It's the same way as Apple in the early days. Apple didn't invent semiconductors. They didn't invent the integrated circuit. They used what was at hand, and they used it intelligently, and that's what Tesla is doing. Tesla capitalized on what we started with at AC Propulsion. Ironically, the easiest thing to do in electric cars initially was performance. A lot of people didn't realize that. They thought that was hard because at the time, electric cars were low performance. They were golf carts. The idea that an electric car would be able to go on the freeway in the 1960s was kind of an audacious thing. If you looked forward, the idea that an electric car ultimately would compete with a gasoline car in terms of a quarter mile or something like that, that was definitely not envisioned. Yet, if you looked at the engineering, if you looked at the theory of batteries and stuff—and that's what I did to a large extent at JPL—you realized that this is not that hard to do. It would be much harder to get range than to get acceleration. So the idea was to go with what you've got, and that's what happened, of course with the EV1, with the Impact, and AC Propulsion's tzero. Then Tesla capitalizing on that first with the Roadster and then going a step further with the S car, where the performance was higher than the Roadster. That surprised people.
ZIERLER: Because it's a bigger car?
RIPPEL: Yeah, sure, and actually building bigger cars is in some ways simpler than small cars because as you scale up, the aerodynamic drag does not grow as quickly as the availability of battery mass. If you make a car twice as heavy and you have twice as much battery, you don't have twice as much aerodynamic drag, so getting range is easier the bigger the car is. Again, people didn't appreciate that. You take advantage of these things, and you take advantage in some ways of people's misperception.
ZIERLER: On the infrastructure question, if I wanted to go cross-country in a Tesla, we've reached the point where I don't have that range anxiety because there's enough superchargers along the way. But what if I drive a Nissan LEAF?
RIPPEL: Good question. Of course, the Nissan LEAF is evolving. If you look at the recent LEAFs, they have a lot more range than they used to. Batteries are evolving. We're going to see at some point where Tesla and others join forces so that the recharge points will be mutually available both ways. Tesla is off to a great start with that, especially for the higher-rate charging. They're charging at something on the order of 120 kilowatts, maybe a little bit higher, for the S Car. Those numbers will continue to go up. It will probably require a lot of new ideas in batteries before we can charge at the megawatt rate, what they call the 10C rate, where you're charging it in amperes ten times the number of amp hours. But this is another thing that one looks at from physics, at least I do, and there's ultimately no barriers there. The barriers are what can we make, what can we manufacture, not what do the laws of physics prohibit us from doing. The vision I have is that we will have batteries that will be able to be charged at the 10C rate. I also think we'll see a substantial improvement in the specific energy. We'll see batteries that will store probably four times as much as the present lithium ion. I think we'll get to 1,000 watt-hours per kilogram, which means it will be easy to make a car with a 1,000-mile range. When you have a 1,000-mile range, that changes a little bit how you look at recharge.
ZIERLER: Like a once-a-month proposition?
RIPPEL: Yes, and especially if you have the high-rate charging. Having lots of little charge points rated at six kilowatts or whatever, I think that's going to go away, and we'll look at that one day as an artifact of the present time.
ZIERLER: Part of the artifact nowadays—to go back to the proprietary issue, one advantage obviously with gasoline-powered cars is it doesn't matter if you're driving a Lamborghini or a Hyundai; you pull up to your Shell gas station and you fill it up. To go back to the Nissan LEAF, it cannot yet charge off of a Tesla supercharger. Where are we going in terms of standardization?
RIPPEL: I think there is going to be a move to do that. It's in the mutual interest of companies to do that. Tesla did what they did not entirely to lock other people out, but because other people wanted standards that were at lower power that they weren't willing to work with. They felt it was inferior. Just like with the way they do batteries and stuff, they've said, "Look, we're not going to be constrained by the dumb things other people are doing. We're going to do what makes best sense." They've had that philosophy, and I like it. When possible, they look at things from first principles, from the fundamentals, rather than from convention. At any rate, I think what we're going to see with charging will be an evolution. I could be wrong, but I think it will be an evolution to fewer charge points than people think, at least public charge stations. I think that the high rate will make sense, and it makes sense economically, not just from the point of view of the customer. You don't want to wait around for 45 minutes while your battery charges. That's an expense to you, but it's also an expense to the guy who has the charge station. He's selling electricity. If you're selling it at the rate of six kilowatts, you're making so many pennies per hour. If you're selling it at a megawatt, you're making $20 or $30 bucks an hour on each charge port. Just the cost of the land you have, you have to think about that. You don't want cars tying up that land as a parking place unless you're getting paid a parking fee!
ZIERLER: If we can broaden out from infrastructure and to think in broad historical perspective, when you first started to conceive of electric vehicles of being commercially viable, however many decades ago that was, and we think to where we are now in 2021—I'm a new car shopper. I'm in the EV market. Are you impressed or are you disappointed with the offerings on the market today for EVs?
RIPPEL: I'm pleased. Now, you'll probably get a different response from Alan Cocconi, because Alan feels that EVs are not as energy efficient as they could be. I agree with Alan, to a certain extent. I think if I were to say what would be the ideal, it would be some midpoint between where Alan is and where the industry is. Alan does not put great value on things like a sunroof, or even air conditioning. He's a spartan type of person.
ZIERLER: Point A to point B.
RIPPEL: Yeah. That class of vehicle, there is a place for that, and especially worldwide. The issue with climate change, of course, is not just the United States. It's the whole world. Electric vehicles, if they're going to do good, they have to become the standard. They have to be good enough to become the standard for around the world.
ZIERLER: Good enough also means affordable?
RIPPEL: Yes. Initial cost and charging are the two weak points, as I've said, right now. Everything used to be weak except for emissions.
ZIERLER: What do you drive yourself?
RIPPEL: I have a Tesla Model 3, which I let my son drive a lot. I really love that. It's the standard version and it has more than adequate acceleration for me. I've driven in the Tesla S Plaid, which has the beyond ludicrous acceleration.
ZIERLER: Did you do it? Did you go zero to 60?
RIPPEL: Oh, yes, yes.
ZIERLER: What did it feel like?
RIPPEL: I think I know what it would feel like to have a rocket engine attached to the car—
RIPPEL: —if it were a large enough engine. It's almost I would classify it as a violent experience. The car is extremely well behaved, but the forces are such that it's not for the faint of heart. [laughs]
ZIERLER: What is your sense of Tesla's business plan of starting with really expensive cars and scaling down to "more"—and I put "more" in quotes—"more" reasonably priced cars like the Model 3, which itself is, what, $50,000, $60,000?
RIPPEL: Yes, yeah.
ZIERLER: It's still an expensive car. What do you think of that business plan and what might it tell us about affordability into the future?
RIPPEL: It is a necessary strategy for getting started. If you watch the movie Who Killed the Electric Car?, the statement is made in the movie from someone at Ford said, "Why should I pay more money for a car that does less, and does that make sense?" What Elon's strategy has been was to strengthen all the potentially strong points. You're going to be paying more for it no matter what, so if you're going to pay more, you should have the luxury items and the things that go with a more expensive car. There's an interesting thing in terms of perception, and I discovered this years ago, when there was some issue with military spending. Someone pointed out that a toilet seat in a military airplane costs $500 and that some other item cost ten times as much. People got really upset when they heard that. Now, the fact that the plane cost $100 million rather than $32 million—the numbers are so big—million, billion, gazillion, it's a big number—but the toilet seat, they could relate to. This is the same principle. You're going to be paying a lot—$50,000 or $60,000 or $70,000. Put all those things in; they don't cost that much. Make people feel that you're not cheaping out. It's the same way as when you go to a hotel and you're paying some ridiculous amount; you don't want them to nickel and dime you for the potato chips that are in the room or something. You'd like that to be included. It's kind of that philosophy. You're paying a lot of money, so at least make people feel they're getting something for it.
ZIERLER: To the race to get that electric car that's affordable, the one that Alan would like to see that just regular people can drive, to the extent that there's a race between the Japanese, the Koreans, the Germans, the Americans, and within the United States, you have Tesla and then you have the big three, who do you think is going to deliver that affordable, normal family car?
RIPPEL: It's something I've thought about a lot, David. First of all, the issue of affordability is pretty much centered with battery technology. The motor drive system is pretty low-cost. It's much less expensive to build per horsepower an electric drive—the motor and the inverter—than to build an internal combustion engine and an automatic. Transmission, probably more than two to one. So the battery is what makes the car expensive, and the battery is also where the limitations occur. The range will always be viewed as a limitation. The recharge rate. The life of the battery. Electric cars to a large extent are bound up with battery technology. When you ask that question, you're really asking who is going to make those breakthroughs in the battery area. Potentially the United States could do it because at least from my point of view—and I'll tell you why I believe this later—but you need a free type of thinking to make the breakthrough.
If you look at the way the semiconductor industry came about, and Caltech played a role in that, it was not people at the conventional electronics companies, vacuum tube companies, that said, "Oh, let's see if we can invent semiconductors." They weren't thinking that way. Bell Labs went into this as a scientific endeavor. Even Bell Labs did not end up building the integrated circuits. They created the people and the knowledge base that allowed people to leave Bell Labs and start companies like Fairchild and others that became what we know as the electronics industry of Silicon Valley. I think that the same is true with batteries. Don't look to conventional battery people, electrochemists. There's a role for them, but I think you need people who are viewed more as mathematicians and physicists and theoreticians. They're not going to solve all the problems, but they're going to open the door to something new. That's the same way with semiconductors. When the transistor was invented, we didn't know how to make it. The theory was there, and so there were really two inventions—the first invention of the so-called point contact transistor, which kind of worked, if you didn't sneeze [laughs] or there was no ground tremor, and then we learned how to build them a number of years later. I believe that that will happen with the advanced batteries. The first thing is the science. I look forward to talking about the role of Caltech with that, because Caltech has at least traditionally been stronger in science than engineering, whereas if you looked at MIT, I'd give them the edge on engineering. So to answer your question, I would say that Caltech has a shot at being the entity that makes the breakthrough.
ZIERLER: Are you following research on campus, currently?
RIPPEL: A little bit, yes. I'll talk about that in a separate thing. My feeling is that it needs to be better funded. My feeling is that it's not part of Caltech's central vision for energy. I think Caltech's central vision is too closely aligned with the fossil fuel companies. I could be wrong there, but from what I've been able to gather, and just connecting the dots, I see Caltech betting on either fossil fuels or at least the fossil fuel companies, if nothing else as evidenced by the lack of willingness to divest from fossil fuels.
ZIERLER: Interesting. Now, the breakthroughs that you envision that will get cars to be much more affordable, let's just run through what the challenges are right now. Let's start first from a resources perspective. Cobalt, that's a rare mineral. It's in difficult places like the Congo to access. What are some of the strategic infrastructure problems as they relate to acquisition of resource and building a large-scale lithium ion supply?
RIPPEL: First of all, when you hear lithium ion battery, keep in mind that there are all different flavors and varieties, and work is being done where the cobalt is being either reduced or eliminated, and it's still a lithium ion battery. That lithium is not changing valence state. I think we will see lithium ion batteries use progressively less expensive materials for the cathode. The anode, as you know, is basically graphite, which is cheap. The lithium is not that expensive. The issue has been, as you mentioned, some of these other materials like manganese and cobalt, a little bit with nickel. But there's a lot of work going on to get past using those materials. There's work with lithium sulfur and some other things where the energy will be increased substantially, and also where a solid electrolyte is used, which then allows you to go to the use of lithium metal, which is higher energy. So I think the broad view of lithium, there's going to be a lot of things happen. We'll call it lithium ion, but they may be very different from what we have right now.
ZIERLER: What about recycling? Where is recycling in all of this?
RIPPEL: It's just getting started. J.B. Straubel, who was the CTO at Tesla, left Tesla and has formed a company to deal with that problem. It's to some extent an environmental issue, but it's also a resource issue. Batteries can be ultimately looked at as a mine. You mine the old batteries to get the valuable materials out. We need to learn techniques for doing that, and doing it cost-effectively. As you know, presently, there's this thing of second life with a lithium battery, where as a battery ages, it loses percent-wise power more rapidly than energy. So the car that had the zero-to-60-in-two-second acceleration has degraded to three and a half seconds, but the range has only dropped 20%, but the battery is no longer what you want. The battery comes out of that, and yet it can be used as storage for utility power, where the power levels are relatively low, because you extract the energy over an hour or more, rather than over a period of a few minutes. So there's the management of giving second life to lithium batteries as well as the processes for extracting the valuable materials and also doing it environmentally. Lead is much more toxic than the materials in a lithium ion battery. Lead is a heavy metal, of course. Everybody's gasoline car has a lead acid battery in it. We've learned how to recycle those fairly well, with the exception of what happened in Vernon with the Exide battery company. If we can do it with lead, I think we can do it with the lithium ion.
ZIERLER: What about efforts to decarbonize our electric infrastructure, to do away with or to move away from coal-fired plants, to rely more on solar and wind and nuclear? What role do you see in the development of mass adoption of EVs?
RIPPEL: Interestingly, EVs and carbon-free power generation are synergistic. Again, the thing that brings the synergy together is batteries. Right now, in some cases, solar photovoltaic is cheaper than coal, but the problem is the storage. The sun, most of us agree, does not work too well during the night, so you need some energy storage both for that, and also the wind doesn't blow all the time. The present lithium ion battery is not economically viable for utility energy storage. When you have a battery in an electric car, the energy coming out of the battery is valued at maybe three times the energy that came out of the wall, when you include the battery depreciation, the fact that you paid for it and it only has so many thousand cycles of life. That same formula, if you applied that to a utility, you start out with energy being generated at let's say five cents a kilowatt-hour, and to store it costs 15 cents, you have to sell it for at least 20 cents a kilowatt-hour, and that's at the upper end in many cases. So battery technology is at the core of utilities being able to go 100% renewable, 100% wind and solar. There will be other generation that is not intermittent, for example geothermal. Of course we'll continue to have the hydro that we have, and we may in some cases use pumped hydro, where you use that as a form of energy storage. But energy storage is the key to our dealing with the future of energy and having a carbon-free economy.
ZIERLER: And an EV in every garage will be helpful at some point in the future?
RIPPEL: Yes, yes. Of course with autonomous vehicles, the one point is that it might not be in people's garages. In some cases, they'll pull up in front of your house. I don't know how much that will be accepted. It may make sense. I'm concerned from the point that you'll have vehicles traveling from point A to B without any passengers, which means more traffic on the roads, which means you're going to have to invest more in the infrastructure of roads. We'll see, but in some cases, I'm sure it will make good sense, especially if you see the way some people drive. [laughs]
ZIERLER: Speaking of infrastructure, to the extent you're following developments in Washington and all of the emphasis on infrastructure spending, is that generally headed in the right direction, as far as you're concerned?
RIPPEL: It's interesting; I am deeply concerned about climate change, and I think it's the biggest problem we have. In answering that, I'm going to go back to how I got started with electric vehicles. In the building next door, Dabney, second floor, I was in a history class.
ZIERLER: Oh, wow! [laughs]
RIPPEL: That was when it got started. We were talking about the Civil War, and then after the Civil War, Reconstruction, and how the United States, instead of remaining a federation, it really became a country. When we hear State Department, that always is funny, because you'd think that it's dealing with the individual states or something. It was a very smoggy day. In those days, in the 1960s, the smog would be so bad that you'd go for weeks without seeing the mountain, the San Gabriels. We were talking about the role of government, the role of federal government, and the role of state government, and how that was apportioned. It devolved in a very natural way into, "Well, what's the role of government in dealing with smog?" The role of the federal government, the role of the state government. It was a very lively discussion.
The pronoun "they" was being used excessively. Someone would say, "they," meaning the federal government, or "they," the state government, or "they," the car companies, and we were getting confused with which "they" was current. One of my classmates, who was pretty smart but also kind of reserved and quiet, said just a few words. He said, "We are they." That was the start for me. The reason I bring this up now is because the issue is interesting. What is the rightful role of the federal government in dealing with climate change? You can see that I probably have some ideas at least in connection with the recharge thing, because I'm aware that the charging is going to be, five or ten years from now, very different from what people think right now. Right now a public charging point may be a six-kilowatt or no more than 15 or 16 kilowatts of power. I believe the time will come when we'll view that humorously. Like imagine going into a gas station where they pumped gas at the rate of a gallon an hour. You'd laugh at that. And while they did that because pumps were not very good—they had this little hand pump, and it took them an hour to get a gallon on, we'd laugh at that. I don't want to see a lot of investment put in things that are dead ends. That's one of my concerns. I believe that there is a role for the federal government to play, and it's one that they don't want to play. If you do damage, if you break somebody's window, the role of the government is to say, "You've got to pay for it. You've got to fix it."
ZIERLER: To enforce that, you mean?
RIPPEL: Enforce it, right. We do that. We do that well, with laws. If I break something, I'm responsible to pay for it. I think the same should be done—you're putting carbon, CO2, into the atmosphere, that is doing damage, and we can now scientifically establish, pretty much, how much damage we're doing per ton of CO2 emitted, so at least what you should do is put a tax on it. Tax it as it's being pumped out of the ground, whether it's coal being dug out or oil or natural gas. Tax it pretty much in proportion to what the damage is. Some of that tax money of course should be used to help people who still have gas cars and are at the bottom end of the pay scale. But I think that a tax can be more effective. When things become expensive, then you go away from it. You go to something more cost-effective. Right now, we're seeing what we think is expensive gasoline. Suppose gasoline were $6 or $7 a gallon. An electric car would seem more like a bargain. Even at $50,000, you'd finance it right and you'd say, "Look, okay, I drive a lot. That will pay for itself in this many years." Already, in many cases, buying an electric car makes sense when you look at the total cost. That's the role, I think, that the government should do. This would not be adding to the deficit. This would be actually subtracting from the deficit so that money could go into the Treasury. But we refuse to cut the benefits we're giving to the fossil fuel companies. We're doing that as a nation, and Caltech is doing it, too.
ZIERLER: Just to get a sense of your overall motivations and aspirations, to establish an extreme end on either side of the spectrum, this is all about concern for resources and carbon emissions and global warming and electric vehicles needs to be adopted on those grounds. Then there's the Tesla Model S Plaid beating a Lamborghini in a zero-to-60. Where are you on that spectrum?
RIPPEL: I'm on both of them. Work I did at JPL in the 1980s focused on power. Beating the crap out of MIT was a wonderful thing in the electric car race. There is that spirit, and it's a healthy thing. I would like to see it go a step further. I'd like to see the Americans and the Chinese go to quote "war" [laughs] over—
ZIERLER: This is a good Cold War going, right?
RIPPEL: The battery war! And let the communists prove that their system will develop a battery faster than we will. We kind of did that with the Apollo program, and we won. Of course looking back, I'm not sure we're as good as we were back then. It would be good for us. I think it would motivate young people in science, engineering, and math, more than anything else. We need that. If you go to a football game and you watch the game, and then you go and watch the athletes working out, wind sprints and stuff, who would do that kind of exercising if there weren't a game involved? So I think having a game involved is wonderful.
ZIERLER: What's the game?
RIPPEL: It can be what you want to make it. Talking about the electric car race in 1968, that was hopefully something that would have engendered interest in batteries. I didn't succeed. Maybe I don't know the best answers. On the other hand, we're in a different world now. One game could be international. It can be universities competing. Universities have competed making electric cars where they get this battery and this motor and put it in. What they end up doing is learning how to drill holes in metal and bend metal. A little bit of that is good. I did that. But you've got to go past that. What we should have is people dealing with the Schrodinger equation, writing physics equations to get insight in how you make a breakthrough battery. I'd like to see a broader spectrum, especially in the more theoretical areas involved. I really think that Caltech has a role to play there.
ZIERLER: On that question of a game, one last question before we take it back to the beginning for you. The rivalry between Caltech and MIT, it reminds me of, if you're familiar, the Cannonball Runs, the races that people do. Now, if memory serves, I think the most common car that has won those races is the BMW M5. This is a car that can cruise at 140 miles an hour for long periods of time. Quick fill-up at the gas station, you're on your way. When will an electric car, Tesla Model S, whatever it is, when will we have the technology and the infrastructure when electric cars will win those Cannonball Runs?
RIPPEL: When we have the breakthrough battery is the answer to that. It's amazing that electric cars are doing as well as they are with the battery technology we have. The lithium ion battery stores eight times as much kind of energy as a lead acid, and the power levels are much higher than people thought they would be. There's another factor of four in energy, I think, that can be obtained, and a large factor in power. There's no bound I see in terms of theory. If you can discharge a battery in six minutes, already we have more power than we know how to handle. The main thing for what you talk about there is recharge time, being able to charge the car. That's where the races will be won and lost, is the difference between a six-minute and a five-minute recharge.
ZIERLER: Just to be clear, electric cars, they can cruise at very high speeds for long periods of time?
RIPPEL: Almost. Gas cars used to be weak. A gas car that would do 140 miles an hour could not maintain that. Most cars will not maintain their top speed without overheating. That's definitely true of the Tesla Model S. I've done work in that area and have patents dealing with improved heat transfer in the motor. I think we know how to do those things, but Tesla hasn't done them yet.
ZIERLER: We're getting there?
RIPPEL: Yes. They don't require fundamental physics. They require just some applied engineering. But the battery, in my view, the breakthrough battery requires first some science, and then you build some small things that may cost a million dollars and be the size of a pea, but they will work and validate that you understand the science. Then you'll learn how to build them. It may take a while to do that, and it will be different from what we see right now.
I'll give an example of where I see the differences coming. If you talked to battery people and you'd say, "What is the one thing that you know will always be the case?"—people said that in the semiconductor era. They thought they knew certain things that would never change. "What is it that will never change?" "Well, batteries, you'll never have a high-voltage cell. You'll never have a 100-volt cell. The lithium ion is pretty high at four volts, and maybe it will get to five volts, but it will never get to 100 volts." And they'll give you reasons, and good reasons, why that's true. But those good reasons may not fully understand all of the physics at hand. I believe that the time will come when we will be able to make a cell that will be a 1,000-volt cell. We'll make these things, make a 10-kilogram, 1000-volt battery that will be 10 kilowatt hours, and that will be enough for a small vehicle. For a large vehicle, you'll put a number of them in parallel. It's much easier to put them in parallel than in series because you don't change the system voltage. That's the vision I have, is a high-voltage battery. There's physics involved that I'm scratching away thinking about, and I know little about, really.
ZIERLER: And to wish you a long and healthy life, do you think this will happen in your lifetime?
RIPPEL: I don't know. I really don't know. Here's what I've learned about predicting technology. When little happens, you can predict the future. The lead acid battery was invented in 1859 and there were just little, small, incremental improvements made, so it would be very easy to predict the future. You looked at it—well, it improved by 2% over this period, another 2% over the same period. That's easy to do. But when breakthroughs are involved, all bets—everything is off the table. You don't know what that's going to be. People are surprised by it when it happens, even the experts.
ZIERLER: But you are saying Caltech is a place to keep your eye on.
RIPPEL: Yes, yes. Caltech may not be betting on the renewable energies the way they should be, but I'm betting on Caltech.
ZIERLER: At the individual level, at the research group level?
RIPPEL: Yeah. It's interesting—some of my best memories here at Caltech were staying up late at night, being out at the hall in Page House, just bs'ing with people, talking about things. This was when the computer revolution was just getting started. I remember things that were said in one particular late evening, and we'd been drinking too much beer. Somebody said, "One thing we know we're always going to have is core memory, because it's cheap." That guy was wrong. Another person said, "The day is coming when the software in a computer will cost more than the computer." [laughs] "What's in your beer? It's more than alcohol!" Another statement someone made was, "The day is coming when an entire computer will be put on one piece of silicon." These were all audacious statements. Some were true and prophetic and some were humorous, and that's how it is.
The one thing that you do have that is an anchor point is the laws of physics. Engineering changes. We've forgotten how to make vacuum tubes, so all those things that we learned are obsolete. But the fundamental laws of physics, that's the anchor point. As a physics person, I revere that, and I feel that should be our starting point. We have not tapped the physics community for work on batteries. We think of this as a chemistry problem, an electrochemistry problem, and it is, if that's what you make it. That's what we're doing. Yet if you look at the evolution from previous batteries to the lithium ion battery, the lithium ion battery looks a little bit less "electrochemic-y." That's a new word I just coined. [laughs] Then if it becomes, with a solid state electrolyte, you'll have two electrodes that are solid, and what's between them is solid. So we're moving to what will ultimately be a solid state battery. It seems that the solid state physicists will have something to say about that.
ZIERLER: We've done so much thinking about the future; let's go all the way back to the beginning for you. Let's start with your parents. Tell me about them.
RIPPEL: My dad, when I was born, was working at NBC Radio, Sunset and Vine. When I was a little kid, he'd bring resistors and capacitors home for me, so I would play with those things and imagine things. As a matter of fact, I have a memory of when I was five years of age, I had taken some capacitors and connected them together, and I took it with me while my dad was visiting a friend, and I pretended that those components somehow were making the car go. [laughs] So my dad played a role in my getting interested in engineering and such. My dad did not finish high school, during the Depression and stuff.
ZIERLER: Where did he grow up? Was he from Southern California?
RIPPEL: No, he grew up in New York. He was fascinated with radio. Radio was a magical thing in the teens and the 1920s. My dad explained that to me, and I didn't appreciate it until I was older. We take it for granted, but the idea that a person would be in their home and be able to hear the president's voice for the first time was an amazing thing, and to be part of that, as my dad was. He didn't initially fully convey the magical-ness of radio itself, but I did gain an appreciation for the fact that you could have these inanimate objects—wires and vacuum tubes and stuff—and out of it would come a human voice that was hundreds of miles away.
ZIERLER: How old was he when he got to L.A.?
RIPPEL: He was about 36 when he got here.
ZIERLER: What was he doing before then?
RIPPEL: He had worked in audio at the Astor Hotel, at another large hotel, setting up audio microphones, amplifiers, repairing the equipment.
ZIERLER: For conferences and events, that kind of thing?
RIPPEL: Yes, yes. He had the opportunity of hearing some of the leaders of the time—the mayors, the president, other people—speak. It gave him a window on the world of what was happening. Then he conveyed to me the magic of engineering. He was my inspiration.
ZIERLER: Was there a specific job that drew him out to L.A. or he had some adventure in him?
RIPPEL: No, my dad had gone through a divorce, and I think he came here to start a new life. It was hard getting employment right at the end of World War II, and it took him a while. He wanted very much to work at NBC, and he ended up working there. I have these wonderful memories of when I was five and six and seven, going to visit him at NBC. He'd show me things. That's where I first saw an oscilloscope, and amplifiers, and different things. I learned the words. I learned the vocabulary. I would talk to some of my dad's colleagues and I thought I knew what I was talking about. They were very patient with me. They enjoyed talking with me. They would even ask me some math questions, and I would struggle at things I couldn't do. But it gave me a feeling of being part of the community.
ZIERLER: What about your mom? Where's your mom from?
RIPPEL: My dad and mom met in New York at I think it was the Astor Hotel. No, the Waldorf, excuse me. My mom had problems with her eyes, so she was a stay-at-home mom. She couldn't drive. She was tremendously supportive and loving for me. I was an only child, and so I was in a way spoiled, because I was given as much opportunity as possible. [laughs] I remember when I was in fourth grade, I was not doing well with my multiplication tables. I got a note that I had to take home for my mom to see, that she would give me help with my multiplication tables. I was so embarrassed that I forged her signature. I worked out a way so that with pinpricks and so on that I'd be able to, I thought, do a way of forging her signature. Well, the teacher immediately caught on. The reason I did that was because I didn't want to disappoint her. I wanted her to feel that I was doing well in school, and I wasn't doing well in math in fourth grade. I did better here at Caltech! [laughs]
ZIERLER: Did your father earn a good living at NBC? Middle-class upbringing?
RIPPEL: It was at the bottom of middle class. It was at the end, maybe okay. I never thought of myself as being poor. On my mom's side, there was an inheritance, which enabled my mom and dad to buy a home in Hollywood, which was nice. But we did everything ourselves, from plumbing to electrical, and it was wonderful. I really loved the growing up learning hands-on, and that hands-on experience helped me as I did the stuff with the electric car here. I did all the machine work down in the basement of Spalding.
ZIERLER: How old were you when Sputnik was launched, 1957?
RIPPEL: I was, I think 12. I was born in 1944.
ZIERLER: Did that register with you?
RIPPEL: Oh yes. What was interesting is my dad was a very proud American, and the idea that the Russians would be ahead of us in anything was just complete anathema to him. He tried to spin it that we were going to ultimately prevail. Well, he was right, but the reality was at the time we were well behind. Unless we had taken a big step like the Apollo, we weren't going to be able to do anything where we would end up ahead. That whole era was a special thing, because I of course had a sense of pride. It gave me an added enthusiasm for engineering. The Apollo program was both engineering and science. It was a very special time for me.
ZIERLER: What about on the road? Were you a car guy when you were growing up?
RIPPEL: No, absolutely not. The first time I did anything mechanical on a car was I had a Ford Falcon starting in my sophomore year. I got to the car and I saw water dripping out of the water pump. Then I started the engine and more water came out. I called my dad, and he said, "Hey, Wally, go over to Pep Boys and get another thing. It's only four bolts you have to take out." That was the first time I had done anything working on a car. It was very simple.
ZIERLER: Back then, you could actually work on your car. [laughs]
RIPPEL: Yes, yes. [laughs] And I miss that! I miss that a lot. After you do one thing, you become open to doing the next thing. But I was definitely not a car person.
ZIERLER: What about a tinkerer? Did you have like chemistry sets, model airplanes, that kind of thing when you were a kid?
RIPPEL: The big thing I had was an erector set. I got that when I was five years of age. A friend of my dad's recommended that he get that for me. I tried to build everything [laughs] with the erector set. I built elevators that went up to the ceiling and all different things. I also had a train set, a Lionel train. I never had a chemistry set, and that could explain why I didn't do as well in chemistry.
ZIERLER: What high school did you go to?
RIPPEL: Hollywood High.
ZIERLER: Big school?
RIPPEL: Yes. There were 3,000 people. I had some interesting experiences there. I was excited about electronics, and I got permission—they'd never allow this nowadays—to teach a class in electronics that I put together. I created the curriculum. A shop teacher agreed he would sit in on every class. The teacher never taught a single lesson. I created all the material. I did the tests and everything. There were about 38 people in the class. I think back, and it in a way seemed crazy.
Then another thing I did in high school is I put together a demonstration with a large stroboscope. I had been inspired by an earlier demonstration that was done by the phone company with a stroboscope. I found out stuff and I built a large stroboscope that would be suitable for the entire student body at the auditorium. I created several things where you couldn't see what was going on because it was moving fast, whirling, but with a strobe light, you'd be able to see it. I had a propeller, and the propeller started out being bent at a strange shape. But when it would spin fast, the centrifugal force would make it pull into a straight line. We had the sound effects of an airplane engine starting, and it made it fun. You just saw the blur with regular light, then when we put the strobe light on, you could see it like it was not moving. I could make it go backwards and forward. There was a drama to this. It worked out very well.
ZIERLER: Did you have summer jobs that were relevant for these interests? Did you ever try to work at NBC with your dad?
RIPPEL: No. What I did over the summer growing up was in the Hollywood house, I got a lot of exercise building retaining walls, concrete block walls. I enjoyed doing that. There was one summer where I literally did not leave the property in my folks' place in Hollywood. I'd be mixing concrete and stuff. [laughs] It was the other side. I just enjoyed the physical building of things.
ZIERLER: Were you a really good student in high school? Did you fix those multiplication table problems?
RIPPEL: Starting in junior high, I wanted to be in the honor society, and I always missed it. I got A's in science, and starting with algebra, I got B's. It was interesting; I had a knack for making mistakes. I still make math errors more than I should, I think. In high school, I finally in Algebra 3 had a solid A, and I went to the teacher and looked at the roll book. She said, "You'll get an A unless you get a D on the final, and you're not going to do that." And I did. Just stupid mistakes, copy errors and things like that.
In geometry, there was a proof that we needed to do, and it was not that hard. It used some theorems that we had recently learned. I thought I'd be cute and I created my own theorem. It was valid. It was a valid theorem! I went through the steps, I solved the problem, and I got zero credit for it. I got a C on the final, and a B+ on the final grade. I argued with the teacher. I said, "The whole purpose of geometry is teaching us how to think. What I did was valid. All the steps I used were valid." She said, "Yeah, but I wanted to see that you had learned these theorems that we had, and you didn't prove to me that you had learned that."
Well, I had the reverse experience my junior year here at Caltech. I had a classical physics class with Professor Eugene Cowan. There was a whole section dealing with the so-called Poynting vector. This is the cross product of the electric field and the magnetic field, and it deals with the propagation of electrical waves and so on. A third of the final was dealing with that, and I had not studied any of this. I didn't think it was going to be on the final, and I was busy doing other things, including the electric car stuff. What I did is, to the best of my ability, I worked out, during the final, what those equations would have been. As you might guess, I made an algebra mistake, so everything was wrong by a factor of pi or pi squared or something like that. [laughs] Professor Cowan realized what happened. He said, "It's clear you didn't study the material, and you blew the algebra." He pointed to where the mistake was. But he said, "What you did was worthy of a physics person. I like it."
ZIERLER: Because it showed ingenuity.
RIPPEL: He took five points off for the algebra mistake, and I ended up with an A on the final, and an A in the class. I realized that Caltech was looking for something different than what my high school teacher was looking for. It's something that I really value, is not the information you have, but the ability to think.
ZIERLER: When you were in high school and you were thinking about colleges, was Caltech the be-all and end-all for you? Is that where you wanted to go?
From Hollywood to Caltech
RIPPEL: That's really interesting. Starting when I was a kid at NBC visiting my dad, my dad would talk about Caltech. When I was a kid, I didn't even know where Caltech was.
ZIERLER: Pasadena is a long way away from Hollywood. [laughs]
RIPPEL: I think it's in the United States someplace! But I didn't know exactly where it was. The first time I went to Pasadena was after I had been accepted here, for orientation.
ZIERLER: It's probably the first time you saw smog too, right?
RIPPEL: Oh no, no, no. Smog was—
ZIERLER: You had that on the west side?
RIPPEL: Oh, yes. Oh, yes. It was bad all over here. So, I had heard about it. It had been kind of a dream. Some of it was because of the encouragement I got from my dad. At any rate, I took the SAT and stuff. When the time came for filling out the applications, I thought about my math grades. I said, "I've had straight B's in math. They're not going to accept me." I told my mom that. My mom especially, she said, "But you've done some things that other people haven't done." Like with the class teaching. Also I would one day a week teach the physics class, and the kids liked my doing it. I got good reports that I was doing a better job than the teacher. [laughs]
All of that was in my application, including an invention, or I thought it was an invention. I was interested in audio, because that was my dad's field. I wanted to make an electronic circuit that would take two voltages and multiply them. In audio, everything is linear. You can amplify. But if you could multiply one thing by another, you could do some very interesting things. I learned, for instance, if you take and apply the same sine wave to both of those inputs where they're being multiplied, you'll have a sine wave that's twice the frequency, an octave higher. I thought this would probably be interesting for some audio effects, but just as a general thing, having a device that would multiply two voltages. I designed what is called a four-quadrant multiplier using vacuum tubes, and I built it, and I got it to work. Then I put a math analysis of that together of how it worked, and I included that in my application to Caltech. The person who was interviewing me was fascinated with that. [laughs] He said, "I went through the math carefully. You have several math errors in there." [laughs] I thought, "Well, he already knows my math." But he was impressed with it. He felt it was creative. Then he pulled an interesting trick. He said, "I notice you took a math class out at UCLA over the summer, and you got an A in it." He looked at me. I had not taken any such math class. I remember a couple of seconds going by, where I'm thinking, "Do I challenge him on this?" And yes, I did. I said, "I did not take any class. That's not correct." He looks at his papers and he said, "Well, maybe I had some wrong information here." I found out what he was doing later.
ZIERLER: He wanted to judge your honesty.
RIPPEL: Yeah. [laughs] That may have been one of the things that determined whether I'd be here or not.
ZIERLER: Was it attractive for you that Caltech was so close? Were you also thinking about a place like MIT?
RIPPEL: Yes. The distance wasn't the thing. I was fascinated with physics, and Caltech had at that time I think the number one reputation in physics in the country. It wasn't that far from World War II, from the Manhattan Project. When I was here, two of my professors had been part of the Manhattan Project. I selected Caltech probably in some ways not having all the information that I should have, being enamored with it, and then when I got here, feeling in a panic. [laughs] Freshman year was difficult.
ZIERLER: That was 1965, you arrived?
RIPPEL: No, I arrived in 1963. I took a year's leave of absence. My freshman grades were not getting that good, in especially humanities. I did okay in physics and math. I had a C in chemistry. I felt I kind of needed a reset. That helped me a great deal. I came back after the leave of absence and I did much better.
ZIERLER: Did you have a good idea of what your major was going to be?
RIPPEL: Yes, right at the outset. I knew I wanted to be in physics.
ZIERLER: Applied physics, specifically?
RIPPEL: What area of physics, that was not clear to me. I really had an interest in energy. I was intrigued with the idea of fusion. Something that a lot of people don't know is in the Feynman Lecture notes, upfront Feynman says a few words about fusion. People don't even know it's fusion. He uses the word "hydrogen." The idea of hydrogen fusion. He made the statement, "This is an important problem. Physicists will solve it." But we haven't, after all these years.
ZIERLER: It's always around the corner.
RIPPEL: Yes. And I think again, it's very hard to explain breakthrough thinking. If Einstein hadn't done the General Theory, who was next in line to do it?
ZIERLER: Could be nobody.
RIPPEL: Yeah, it might not have happened for quite a while.
ZIERLER: As a high school student, was a name like Richard Feynman known to you?
RIPPEL: Oh, yes, I've got to tell you about that. This is a fascinating story. I had heard a little bit about Feynman. I got my books several weeks before classes started, and then there was a tour that was offered. I came here and there were about half a dozen other students on the same tour, being led by a grad student, Frank Winkler. I remember his name. We went various places, and finally we ended up over in the Synchrotron Laboratory. Then we got handed off to—and I was sure this was somebody's dad, because he had this Brooklyn accent, and he was touring us. He couldn't have been a faculty person, I concluded, because he wasn't using the big words. He'd say things, "When the protons crash into the target over there, all hell breaks loose!" No, no, when they impinge on the target! [laughs] We climbed up places, looking down on the synchrotron, and all different things. I knew he knew something about this, but I didn't know who he was. After it was all over, I introduced myself, and I said, "I didn't get your name." And he said, "Feynman." He didn't say "Dr. Feynman" or anything; he just said "Feynman." I said, "Are you related to the Feynman who wrote the physics book?" He said, "Oh yeah, close relative of mine!" [laughs] I could see some of the grad students looking—"God, they're getting dumber than ever!" [laughs] It was an interesting experience.
I had a second experience with Feynman. I got to a lecture late, a physics lecture, sophomore year. Because I was late, I went in through the back door of the lecture hall, and quietly sat in the back row. A couple of minutes after I had taken a seat, Feynman came in, and he sat about five or six seats over from me. He was doing the same thing; he didn't want to disturb. The lecturer gave some equation that the student up front thought was an error. Toward the end of the lecture, this guy sitting in the second row raised his hand and he said—and it was a guest lecturer we had—"Professor So and So, I think equation 17 is actually wrong." The guest lecturer felt that it was wrong, but he didn't want to say it was wrong because he could see Feynman sitting up there. But none of the other students knew that Feynman was there. There was a period of about ten seconds of silence, and then Feynman stood up in a loud voice and said, "The young man in the second row is right! Equation 17 is wrong!"
RIPPEL: Afterwards, people said it was like hearing the voice of God say, "I too have sinned." [laughs] But it left an impression on me, of what science is. Science is being honest. It's being honest about when you have an error. It's not being political and trying to spin things and give an excuse for it. That was something that, to this day, I really revere. It is what I would like to see the country become, the world become, where you have a debate between Democrats and Republicans and the Democrat points something out or vice versa, and the other side says, "Thank you. I made a mistake there." What a different world that would be. It would be wonderful.
ZIERLER: In terms of the curriculum in physics, how much of it was on the theory side, and how much of it was on the applied side?
RIPPEL: First of all, I was the first class that used the Feynman lecture notes. That was used both for freshman and sophomore year. Feynman himself was a theoretical physicist as you know, so there was a strong emphasis on the theoretical side and understanding things in a good way theoretically, understanding how things connect. We also had the labs. In the labs, you're doing the work of an experimental physicist. So we had contact with both. The one experiment we did in a lab was the Mössbauer experiment, which was a profound thing for me. I think I appreciated that more than most people, that you could move something at a centimeter per second, and the Doppler effect was significant. The speed of light is 300 million meters per second, and one centimeter per second versus 300 million meters per second, to see that effect, that was profound, and the fact that you're shooting bullets and the target is responding en masse. It's like, as one person put it, a soldier firing a gun and the recoil momentum being given to the entire platoon. The physics of that intrigued me, and I feel that holds a key—the Mössbauer effect, at least in philosophy, may hold key for how we're going to end up doing fusion, rather than using brute force, where we can take advantage of the wave nature of matter.
ZIERLER: When did you start to hang out in the shops here and get to building stuff?
RIPPEL: That all happened with the electric car. Let me go back to just the moments with the electric car. The first moment as I mentioned was in history class, thinking about what can we do. Then the next thought is I took that personally. What could I do? What should I be doing? This was during the time of the Gemini missions with the space program, where you had two astronauts in orbit. Gemini was a steppingstone to Apollo. It enabled us to do rendezvous in orbit. The spacecraft was powered by a fuel cell, where hydrogen and oxygen was used, and the chemical reaction produced electricity and water, and we'd be using a similar fuel cell in the Apollo. The reason this made such good sense is because the water was drinkable. The product of the reaction was something you could drink, which was definitely better than when you burned gasoline. [laughs] That caught my attention right away. I contacted some people at JPL. I didn't fully appreciate that JPL was not involved with the manned space program, and I thought maybe they were doing stuff with fuel cells. They weren't, but I talked to some people in the electrochemical section, where later I would work, and I found out that the size of the fuel cells was too small to propel a vehicle, and that I wouldn't be able to afford them, and that even if I could afford them, I wouldn't want them. The amount of support needed to maintain operation of a fuel cell, the longevity of everything. I realized that at least at that time, which was 1965, the fuel cell was not an option for a vehicle. Now, General Motors had put a fuel cell in a vehicle to demonstrate that it could work. They called it Electrovan. But it was purely a laboratory curiosity, and it was used once, perhaps, on the road. Also the danger of dealing with the liquid hydrogen at the time—it boils off, and hydrogen is not a good thing to fool with.
ZIERLER: What about the smog? Was that a motivating factor as well?
RIPPEL: Oh, absolutely. As I mentioned, that critical day in the history class was a very smoggy day. The question was, so what could General Motors do? What could the federal government do? What should the state of California be doing? Then ultimately, when Neil Wright spoke up and said, "We are they," meaning the "they" that really counts is Caltech, that's been kind of something I've felt all through these years. "We are they." We have a role to play. I spent some time, a couple of weeks I think, looking at fuel cells. Then I went to look at batteries. The first question I had was power plants, because I knew that you're going to get the electricity not just from hydro, but you'll get it from steam plants that burn coal or oil. I wanted to know if that would be a step in the right direction or not. It was fortunate, at that time, Dr. Haagen-Smit was in his prime here at Caltech doing research. He had already established that roughly 80% of the smog in the greater Los Angeles area was due to automobiles. There was a lot of controversy about that. The car companies didn't like that, and it was a challenge for Caltech dealing with that. But I spoke with Dr. Haagen-Smit personally and learned a number of things about smog.
ZIERLER: What was he like?
RIPPEL: Dr. Haagen-Smit was old school. He was truly a European. He had the accent. He was a very courteous person, at least that's how I perceived him. He had a natural humility and yet a lot of knowledge. You learned something from him, and then you could go deeper and deeper. He had learned a lot about the chemistry of smog. The superficial thing I learned which was I guess the only thing really necessary was that the large majority of smog came from gasoline cars. Now, at the point, that didn't make the case for electric cars yet, because I needed to know something else. If all the cars in the Los Angeles area were electric, how much electricity would that be? If you had to increase the electricity by 50 times, that wouldn't be very good. But I knew that the electric utilities were creating no more than 20% of the smog, and likely less, because there's still refineries and other industry in the area. I did the calculation. I figured out how much energy it takes to propel a vehicle, and I estimated for efficiency for batteries and chargers and motors and so on. I was able to do that. I realized that if every car were electric, and trucks as well, electricity generation would have to increase by only about 20%. Put all the numbers together. That was my aha moment. I realized that from an emissions point of view, electric cars made sense. But then came the bad news. [laughs] Batteries, how bad they were.
Batteries and Smog
ZIERLER: When you said you started to get involved with batteries on campus, where? Where were the batteries?
RIPPEL: First it was just theoretical. The first thing was, how much energy is stored in a lead acid battery, how much does it cost, how long does it last. I got that information together, and it was not encouraging. But then I realized, "Okay, this is why we don't have electric cars is because of the battery. They're bad. If I build an electric car I could build something that will be good enough that I can commute from Pasadena to Hollywood." Where I would be living. I'd be living off campus as a junior and a senior. I saw it as something that would work personally, and I thought this would also act as a catalyst to get other people into the technology and batteries and motors and all of this stuff. The idea of converting a gasoline car to battery power intrigued me. I got a summer job working at Litton Industries. I earned about $1,000 over the summer. That allowed me to buy, for $700, a 1959 VW Bus, and also surplus electric motors. I got batteries donated from a golf cart battery company, from Trojan Battery.
ZIERLER: What were you doing at Litton?
RIPPEL: I worked as a technician in connection with an encoder thing for the military. Encoders are things where you turn a shaft and it tells you what its position is. These things are important for all sorts of things—for telescopes, for putting things in orbit where you want to position cameras and things like that. They had a technique that would make a better encoder than had ever been made, a higher resolution encoder. They were using an electron beam machine so that you didn't have the optical limitations of printing on a conventional photosensitive surface. You could do it with higher resolution made possible by an electron beam, the same theory as an electron microscope versus an optical microscope. Logic circuitry was needed, just very simple stuff where you had counters and logic gates and stuff. All of that stuff was very new at the time. I breadboarded that and got it working. It was interesting; all of the stuff was working, and we were setting up to do an actual print. There were a bunch of these little switches, and you had zeroes and ones, getting them in the right sequence. I was getting all these switches switched, and all of a sudden, the lights flickered and there was an explosion in the building. Smoke came out. It was funny; my first reaction is, "What did I do wrong?" Of course something had happened that had nothing to do with what I was doing, but for five or ten seconds, there was this feeling, "What did I do wrong?" [laughs] Here was a little power supply putting out a couple of watts of power to power this thing. But it is a moment that I remember! [laughs]
ZIERLER: Is this "The Bus"? The 1959 VW Bus?
RIPPEL: That's right. The Bus, yes.
ZIERLER: What were your dreams for the Bus? What did you want to do with it?
RIPPEL: What I wanted to do is get it to the point where I could use it on a daily basis, where I could demonstrate some utility, and especially to garner interest here on campus. I talked to some of the people in chemistry about batteries. I talked to Fred Anson, who was then the electrochemist. There wasn't a lot of interest in batteries. I could understand why. Batteries were empirical. You didn't write equations. You built some things, and it didn't work, and you changed some things, and it didn't work, and you kept changing it until it kind of worked. That's not something that Caltech would want to be involved in, and I agree.
On the other hand, I felt that maybe batteries could become a science. We're just trying to get there now. Batteries, ever since the first battery done by Volta in essentially 1800, and then through the Thomas Edison era, have been empirical. You try something, and if it works, you go with it. If it doesn't, try something else. That's why it's expensive. As you go down that road, it starts out very simple. You cut some lemon slices and stack them with zinc and copper disks and it works. Then you say, "Okay, now what do I have to do to make it better?" But at some point, it gets very difficult. What Sony did with the lithium ion battery took them many millions of dollars to get something that was marginally working. We have to have a different approach. It has to be more like semiconductors. When Intel says, "We're going to make a new chip," you don't have to do a bunch of trial-and-error stuff. The science is there, and the layers of science have been established. We need to do that with batteries, especially if we want a breakthrough battery. So that was kind of my dream, is that I'd get something going here at Caltech. After the vehicle was together and I was driving it, there still wasn't a lot of interest.
ZIERLER: Physically, where were you keeping it?
RIPPEL: During my junior and senior year, I was commuting, so I would have it at home, at nights. Then during the day, I'd park it at the building and grounds, and reel out an extension cord so I could charge it during the day so I'd have plenty of charge to get home. I had enough charge to make it round trip, but [laughs]—range anxiety—I wanted to top it off, so I would always charge it when I was here during the day.
ZIERLER: If you could explain, how much of this is a retrofit? Are you pulling out the entire engine?
RIPPEL: Oh, absolutely. Yes.
ZIERLER: What are you keeping?
RIPPEL: What I kept was the transmission. The conversion was done in two steps. First, it was very crude. I had two surplus aircraft motors coupled with a chain drive. The distance between mechanical failures was about the same as the range of the vehicle. [laughs] It was very unreliable. But it worked, and we got a little bit of press coverage with The Star News, and there was enthusiasm from the point of view that I was doing something aiming toward the smog, and that I had this vision for being able to combat the smog ultimately through electric vehicles. But everyone realized they had to be an awful lot better than what I had. Partly because of that initial interest and so on, there were some donations that came in. I found out about a company in Ferndale, Michigan, that had converted some vehicles and driven them from Detroit to Phoenix, Arizona, where they used a large charger that was carried on a pickup truck to each recharge point. It took them about a month to get from Detroit to Phoenix, but in the process they established contact with the electric utilities. Also this company had access to a motor that was very much better than what I had. They had a motor similar to the motors used in the early electric cars, in the Detroit Electrics of the early 1900s. [laughs] Kind of strange that you have to go back in time to get something, but that's what it was. Through them, they donated a motor and batteries to us, and I upgraded the vehicle. I now had more battery, more battery weight. I now had significant range. The range went up to about 60 or even 70 miles if you drove carefully. The car, I could get on the freeway. You'd get up to 55, 57 miles an hour, and if you stayed in the right lane, people didn't pay too much attention to you. I drove on the freeway with that.
ZIERLER: Now why a Bus? Why not a Beetle which I assume is lighter, more aerodynamic?
RIPPEL: Good question. I picked the Bus because I figured I'd have all that payload capability for the battery. I'd be able to do things easily, and it was an easy vehicle to install things in. But it had the negative, of course, of having an aerodynamic drag that was a lot greater than the Beetle. I don't think I could have put the 2,000 pounds of batteries in the Beetle, though, so that was my choice. It was an interesting and iconic vehicle. Before I upgraded it, the original set of batteries was built into seats, so you could put seven people in the car. The original golf cart batteries gave maybe a 30- to 40-mile range. Then when it was upgraded, I had a lot more range. That's when I decided, if there's going to be any hope with the electric car, we've got to get people interested in working on the battery problem. I then directed my interest to what can I do with this vehicle that's working to garner interest. It wasn't working too well [laughs] in terms of getting any faculty lined up for working on batteries here. My first idea was to have a drag race between my vehicle and a truck that the Los Angeles Department of Water and Power had. I shared that idea with one of my classmates, and he said, "Wally, you're not going to accomplish anything with that. It's going to be a step backwards. You're going to have a drag race that will be one of the lowest performance drag races in history. It will probably be known as that, and it'll push people away from electric vehicles. That's not what you want to do." Reluctantly, I agreed with him, that it wasn't a good idea.
ZIERLER: What was acceleration like in the Bus?
RIPPEL: If you talked about zero to 60, it didn't exist. The vehicle didn't quite get to 60. We would joke we never knew because the battery would be depleted before you'd get to the top speed! [laughs]
ZIERLER: But like on-ramping to the freeway, was that scary?
RIPPEL: It took a little skill. The zero to 45 miles an hour was maybe 15 seconds. Then the acceleration was dropping off. So you'd look and make sure that there's no trucks doing 60 miles an hour that are close by, and you could do it. But it was the opposite side of where Tesla is today. [laughs] It was a step above a golf cart, for sure.
ZIERLER: You wanted to garner more attention for this.
The Great Electric Car Race
ZIERLER: When does MIT enter the picture?
RIPPEL: The next thing, I got to thinking—a really audacious idea—suppose we had an electric car race across country. What this would focus on is one of the weaknesses of electric cars, which is recharge. It would also be a test for survivability of things. It would test a number of things. It would put everything out there. You'd drive a stake in the ground and show where it is, how bad it is, whatever, but it might also inspire a few people that would say, "Okay, if you can do that now, we can do better." I thought there would be a chance of sucking MIT in because of the idea of rivalry. That would be kind of a mechanism.
The first step I felt would be to get some communication with MIT, so I met with Dr. Fred Lindvall. He was the dean of engineering at the time. I told him my idea, and I said, "If you could write a letter to your counterpart at MIT, who in turn would explore and see if there's student interest in doing something like this, that would be great. I think this would be better than my trying to contact the students on a cold basis—‘I'm so and so at Caltech and want to challenge you.'" I felt that the dean would have better luck in communicating with students than I would. Fred Lindvall was not impressed. He said, "Okay, Wally, you write the letter. I'll rewrite it and send it on to Dean Brown at MIT." I wrote this letter the best I could, and he rewrote it and sent it on. I never heard exactly what happened, but one of the stories I heard is that Dean Brown got this letter, thought it was a foolish idea, but he made the mistake of expressing what a foolish idea it was when some students were listening, and some undergraduates thought, "Gee, this is cool. The dean thinks this is a dumb idea."
ZIERLER: "Challenge accepted."
RIPPEL: Yes! "This has got to be really cool!" [laughs] So they formed a group. Leon Loeb became the head of the group.
ZIERLER: Just to be sure, no one was working on batteries and cars there?
RIPPEL: No, but they were working on something called a DC brushless motor, with the possibility of electric propulsion, for electric vehicles of some type. Today's electric cars, with the exception of some of the Teslas, are all powered by DC brushless motors. Theirs was different. It was an axial gap motor. It was a clever design, very simple. A grad student was doing his PhD on it. But the big challenge was - to make it into a motor, an inverter was needed. Inverters were almost impossible to build, then. We didn't have the components. General Motors had built two electric cars known as Electrovair and Electrovan, which used very expensive inverters. This technology had been developed for the military for torpedo drives, and they put this into a vehicle to demonstrate that you could in fact get reasonable acceleration that was similar to a Corvair using an induction motor and a thyristor inverter. The inverter was a tremendous thing, and it was very unreliable. MIT tried to build an inverter using transistors rather than thyristors, and they burned out hundreds and hundreds of transistors in the process of trying to make it work. The components weren't there, nor was the theoretical understanding. There were a lot of things at that time we didn't understand, if you were going to do things. Today, the best engineers probably could make those semiconductors work because of things we know that they didn't know back then. MIT put a lot of effort into trying to build an inverter, and they had to give up last minute. They used the same type of drive system that I had, a series motor with a relay controller. Their controller was cruder than mine. The car was jerkier than mine. But it worked. They had NiCad batteries; I had the lead acid.
Well, at any rate, the student interest was good, but they were not committed to the race yet. The thing that enabled MIT to actually commit to it was the press. The press wrote about this. They heard about it. They wrote about it as if it was a real event. It wasn't real. MIT had not agreed. There were liability issues, and insurance, and everything else. When the press started writing about it, MIT kind of got drawn in through that press coverage. The press, as I've often said, they bootstrapped it into reality. They played a role. Without the press, there would have been no electric car race.
ZIERLER: The competition was too delicious—MIT and Caltech.
RIPPEL: Yes. In the process, I kind of lost some of the momentum or the focus on batteries. The rivalry between Caltech and MIT became the thing the press was interested in, and if I talked to them technically about batteries and specific energy and power and stuff, they weren't interested. They were interested in what was happening right now between the two—
ZIERLER: Who is going to win.
RIPPEL: Who's going to win, exactly. And the race really was exciting. It had some fascinating twists and turns.
ZIERLER: Were you tinkering with the race in mind, or was your prototype ready to go?
RIPPEL: Oh, it was both. The main thing that I had to develop that I wasn't using was the high-rate charger. I tried to build a solid state speed control where the charging function was an integrated function with that. It was what we called a three-in-one. It would provide the driving, the charging, and also regenerative braking. It assumed that I could get thyristors to work in this environment. I spent a lot of time in the basement of Steele working on stuff. At the last moment, I had to give up, too, on the solid state stuff, but I did get a charger working. The charger, it was a lot easier to do with thyristors, because you didn't need what are called commutation circuits, and the technology was there. I built a 30-kilowatt battery charger that would work off of three-phase power. MIT built a much more powerful charger. Theirs was capable of at least 60 kilowatts, probably more. They had nickel cadmium batteries, which potentially could have been charged in 15, 20 minutes. Mine would take the better part of an hour, so I had the lower-power charger. But 30 kilowatts of battery charging in those days was considered horrendous. It's still higher than what most people do with it.
ZIERLER: Is this a one-man show for you? Who are some of your partners here at Caltech?
RIPPEL: It's interesting—it was a one-man show, and that was a weakness on my part. I talked to faculty where I could, and there's interesting stories of my talking to people. But in terms of doing the actual work—one professor took me under his wing, Professor Jerry Shapiro. It was he who introduced me to the machine shop. Don Laird was the head of the machine shop at that time. He showed me basics of using a lathe and a mill and safety and all that, and making sure that I would clean up after myself. I was permitted to work in the machine shop, and I would do stuff between classes and after class. Sandwiching things in was an art, between that and homework and classes.
ZIERLER: What about fellow students? Did you enlist anybody from your class?
RIPPEL: No, no, initially not. When the electric car race became a reality, I realized I need some people to help drive the vehicle, because we're going to be doing this 24 hours a day. I had two friends, and I asked them, and they said, "No, I'm getting married." The other guy said, "I've got a job lined up." But then, because of the stuff with the press, several people came to me and said, "I'd like to be part of the team." I was looking initially for two people, and instead I ended up with five people. It was just a blessing that I had the five. I didn't realize that I really needed more people. I learned some things about the human side in connection with this, and especially in the course of the race.
ZIERLER: Who decided the ground rules?
RIPPEL: I wrote the rules initially, and I talked to Leon Loeb who headed things up at MIT. Initially, he pushed back on the idea of doing 24 hours a day. But then what happened is they realized they needed more time. They'd be starting late, and people were going to grad school. He then accepted the idea of 24 hours, because it would fit in with the schedule that [laugh] he could come up with. He accepted it on that basis. We disagreed on things of what do you do if you can't get to a recharge point. They wanted to tow; I wanted to have a diesel generator. We agreed you can do either, so we had the rules expanded. If I used my generator, any time I connected to the diesel generator, there would be a half-hour penalty. Any time you tow, there will be a five-minute-per-mile penalty. But we had other penalties. If you add weight to the vehicle, if you replace a battery, and I forget the constant, but for each pound that you add, whether it's a battery or a motor or anything, you will be paying a penalty for that. We would have to pay some penalties along those lines as well. We pretty much agreed on things.
There was a little bit of pushback, and I would say there were two or three iterations and we had the rules nailed down of when we start, what the electric utility power would be, the maximum power. There was also an agreement that if it's not dealt with in the rules, you can do it. We tried to think of all possibilities. For instance, we said that if you tow the vehicle, towing by a motor vehicle or towing by an animal would have the five-minute per mile penalty, but we allowed people to push the car without penalty, because we didn't think people would push it too many miles.
ZIERLER: Is the driving team in the car, or are they shadowing in another car?
RIPPEL: That was interesting. That was one of the things discussed. I wanted to keep the driving team in the car. MIT had a lot of people and they wanted to be able to recycle, which in their case was really necessary just for survival. I agreed that you could do that. But we kept—there were three of us who drove the electric car—Ron Gremban, George Schwartz, and myself. We were in the electric car at all times. There was the weight penalty of having three people in the vehicle at all times. George weighed 200 pounds at the time, I think.
ZIERLER: What about the route? What were the options? Did it have to be the identical route going in different ways?
RIPPEL: The route was established pretty much by Electric Fuel Propulsion, who had done that thing from Detroit to Phoenix. They had the contact with the electric utilities. It was pretty much US-66 most of the way, and then I-90 or whatever on the East Coast. It was established pretty much through what the utilities could do and what the contacts with Electric Fuel Propulsion had been. I didn't have too much input there. I passed those things on to MIT, and we agreed that the distance between recharge points should not exceed about 60 miles. In that sense, the route was important. But other than that, it was what came out of the company in Ferndale, Michigan.
ZIERLER: How much did you know about MIT's technology and what were you feeling at the beginning of the race about who would win?
RIPPEL: I was a one-man show, and I knew that MIT was a big place. I knew that they were starting stuff with AC drive. I had heard this stuff about the motor and stuff. I felt that they had an edge there. They demonstrated also their proficiency in getting donations. They got a $20,000 set of NiCad batteries donated. They got a new General Motors Corvair donated. On my side, I got some semiconductors donated from International Rectifier. I got some tires donated from Firestone. The donations were much less. But in some way, I didn't need it, because I already had the vehicle.
ZIERLER: How much attention did this garner among the Board of Trustees, the president, the provost? Was Caltech institutionally paying attention to this?
RIPPEL: Toward the end, they started to, and they said, "You are going to be representing Caltech, and what happens if you have an accident? What happens if you start an electrical fire? What happens if you overload some part of the grid and knock stuff down?" So Caltech put together a million-dollar insurance policy for us that I didn't think would be needed. But we were insured for [laughs]—I think they applied for a two-week time. They figured that would be enough time to either quit the race or to get where we were going. So toward the end, because of again the press, Caltech got involved. But it was interesting—Dr. DuBridge, who my family kind of knew—because my mom and dad were involved a little bit with the Caltech Service League. Through that, they got to know the president's wife, Arrola.
ZIERLER: I'm not familiar with this. What is that, the Service League?
RIPPEL: The Service League was an organization that would help students. Like during Christmas vacation, those that were staying here, they'd provide meals and different benefits to the students, just kind of like the Y would do, later. Through that, my mom knew President DuBridge's wife, and ultimately I got to know Dr. DuBridge as a friend, because really of my mom and my dad. Dr. DuBridge was an interesting person. He was easy for people to talk to. He would talk to a Nobel physicist one moment, and the next moment, he'd be walking, and the custodian, and he'd stop by and talk to him. "How are things going? Are there any problems you're having?" He was an amazing person, he cared for other people, and he had an amazing mind of knowing who could do what. We found this out when he was a guest at Page House, and people asked him questions about scholarships. It seemed like he knew every scholarship and the opportunities different universities had. He was an encyclopedia of knowledge. But very humble. An amazing person.
But he did not talk about the electric car race as Caltech versus MIT. He used my name. I was aware of that, and I came back—visiting, I was part of a parade here in Pasadena a couple months after the race. I visited him, and I said, "I'm honored by this, but why do you do this?" He said, "Well, do you know what my number one job is?" I said, "You're the president of Caltech." He said, "Yeah, that's my title, but what's my job?" He said, "My number one job is to bring funds into the university. There are things here that are very sensitive that are a problem." He said, "I've said enough. You can figure the rest out." Others told me—we had close ties then, as we do now, with what became—it was originally Union Oil Company, and now it's Chevron. Fred Hartley was I think the head of the Board of Directors at the time, the chairman of the board. So the electric car issue was a sensitive issue. I didn't realize it. My take on it was, "Why would an oil company worry about this technology? [laughs] It's worse than you realize!"
ZIERLER: Seriously! [laughs]
RIPPEL: But I think they were worried that it could change, and they may have had more vision than the rest of us have. I don't know. But it was an interesting thing with Dr. DuBridge.
ZIERLER: Where did the race start for you?
RIPPEL: The starting line was on what was known as Creasey [?] Street, which no longer exists. When the campus was rebuilt, that street disappeared. San Pasqual used to go through the campus, and Creasey Street bordered on the student center, originally Winnett Center, and the other side was Franklin Thomas, now is Gates-Thomas. There was a line that was painted on the street there, and that was our starting line, and that was MIT's finish line. MIT did a similar thing. A line was painted out on I guess that's Massachusetts Avenue, and that was my finish line. Now, when I crossed that line, I went another half a mile, because I figured, knowing the MIT students, they might have put a fake line there [laughs] and I would end up wasting my time and they'd say, "Oh, you haven't crossed the finish line yet." [laughs] I just wanted to make sure, so I kept driving for another half mile and then I came back. [laughs]
ZIERLER: What was the communication system? How did you know that MIT and you were starting at the same time?
RIPPEL: In my communications with Leon Loeb. These were phone conversations that I had often at my folks' house. I'd call Leon at a certain time and we would discuss the rules and other things. Originally, the race was going to start not on August 26th but on August 19th. We were both facing problems and uncertainties, and so we mutually agreed to delay it for another week. I brought a number of things here to show—
ZIERLER: Oh! Wonderful.
RIPPEL: Some things you've seen, but—you've probably seen the E&S magazine.
ZIERLER: Yes, yes.
RIPPEL: The account given here is reasonably good. Most of this was written by Dick Rubinstein.
ZIERLER: Who's that handsome young man?
RIPPEL: That's how I looked when I had hair on my head. It's amazing what half a century does. Then I have some pictures from the race. Also I have this. And you can have this; I have some copies of this.
ZIERLER: Oh, thank you!
RIPPEL: This was done by Machine Design magazine. Machine Design magazine had cars which followed both MIT and Caltech to make sure we didn't cheat on the rules that we had agreed upon. Originally, we were going to have General Motors do this. I had been in contact with some people at General Motors, and it looked like it was going to work out. Then right at the end, they said, "You know what? Corporate just doesn't want to do this. They feel it's not in their interest." Through some help of the faculty, we found out that Machine Design would be interested. They scrambled, and last minute they sent somebody out here, and someone with MIT, who was with us every minute of the race. On our side, it was Sam Barnes. I forget the name of the person on the other side. The MIT side of the race was more exciting than our side. They had more chaos, and more problems, I think, than we had. We had some interesting problems, but—
ZIERLER: What were they? What were some of the key problems you had?
RIPPEL: Some that I had, or some that MIT had?
ZIERLER: Start with you.
RIPPEL: The race started out pretty well. We got to the first recharge point. I'll show you an example of what a recharge point looked like. This is where we were, right on that starting line at Creasey Street. You can see here I am, Ron Gremban and George Schwartz. With the motor, you can see the series motor, that bolted to the transmission. I had built the shaft adapter and the housing adapter in the machine shop, and other things had to be done. This is an example of a recharge point out in the California desert. We had, as I'll show you in a moment, a list of all these places and what the mileage was. As we were driving on US-66, we thought, "Well, we should be getting near to Hector in five miles from now," but we couldn't see anything. Good visibility. We could see a little yellow truck. You can just see the beginning of it here. We joked and we said, "Well, that must be Hector." Fortunately, we saw a little cardboard sign that was scrawled "Hector" with an arrow, with a dirt road, and the dirt road led over to this utility pole, and wires—you could see them draping down—were in the sand. They were live. No one was around. Maybe a rattlesnake might come out and get shocked, but no one was around, and just the utility truck was there, and they connected us to power. That was the Hector recharge point.
RIPPEL: The first recharge point, which was San Bernardino, we got power out of a manhole. In other cases, they'd climb a pole and wires would be draped down from the pole. Each recharge point was different, and each one was an adventure. At first, everything was going fine. The charger was working fine. The batteries were getting warmer and warmer. It was August, and we had 100-degree temperature, and the batteries were heated more during recharge than during driving. It got to the point that there were tar seals around the individual cells and the tar started to get soft and gooey. We were concerned about doing damage to the batteries. On the other hand, the high temperature actually increased the performance. Chemical reactions get better as the temperature goes up. On the other hand, the rate of damage goes up dramatically as the temperature goes up. We knew that we were probably going to do some damage to the batteries, but also they were working pretty well.
ZIERLER: How do you mitigate that when the batteries are that hot?
RIPPEL: Well, that's part of the story here. [laughs] We were having some problems. It wasn't a disaster but we were concerned about it. We realized that I hadn't done a good job on providing cooling, heat transfer for the batteries. But MIT had a real disaster on their hands. Shortly after the first recharge point, they couldn't drive because the batteries got so hot. They had to pull over and try to let things cool down, try to put blowers on the batteries. We heard what was happening through the news media. There was just some reports on this. My concern was that the race was going to come to an end, at least for MIT. We agreed we'd still drive across the country to MIT and embarrass them—
ZIERLER: It's a lot less exciting, though.
RIPPEL: But I wanted for it to be a real race. The second day of the race, MIT did the only thing they could do; they started applying ice on the batteries. Imagine this—200 pounds of ice on top of these exposed terminals, this water melting down. You're charging, and the voltage off of ground is a couple hundred volts. It's fatal voltages, especially when you mix water with it. There was that concern. They were careful. It worked so well—we started tracking them. We said, "My gosh. They're not only back in the race, but if they keep doing this, they're going to win the race." So starting with the third day, we started piling ice on top of our battery. Only 50 pounds, though. [laughs]
ZIERLER: Because your batteries are not getting as hot as their batteries?
RIPPEL: That's right. Less heat, and a little higher energy efficiency. When we crossed in Oklahoma—so now as we progressed, we were going to recharge points where MIT had already been there—people said, "Oh, the Caltech car is so much more efficient. It only uses 50 pounds of ice!" [laughs]
ZIERLER: [laughs] What was it like when you crossed the MIT guys on the road? Did you wave? Did you stop?
RIPPEL: No, we were at the same recharge point. We got to the recharge point first, and we established some type of communication. We had a walkie-talkie. We wanted to embarrass them as much as we could. We said, well, if they need a tow, we'll be there to help them. They put inside my vehicle, without my knowing it, a thing that says, "Committed for destruction by the MIT guerilla force," something like that.
RIPPEL: But we had fun meeting each other and throwing barbs at each other a little bit.
ZIERLER: It must have been a true tie at that point, meeting at the same place in Oklahoma.
RIPPEL: Well, no. I think MIT was favored to win at that point, because of—
ZIERLER: They had traveled farther than you had at that point?
RIPPEL: Yes. At least that's my recollection. It gets complicated because of the penalties. We had already been out of the race for a day because of a blown motor. That's a fascinating story. The same thing happened to MIT. We both had some major problems. At any rate, in terms of problems, things went pretty well for the first part. The main thing was battery heating. Then we finally got into cooler weather, and when we saw temperatures start to come down a little bit, we felt we could live with it. Then especially with the ice being applied, that problem was behind us. We got to Kingman, Arizona. We knew that the next—we had like 86 miles to drive from Kingman to Seligman, Arizona. We knew that would be beyond our range, so we knew we were going to have to use the generator.
ZIERLER: What's the range-meter in the Bus? How do you know when you're almost on empty?
RIPPEL: Good question. First of all, you know by miles. You've driven so many miles. We had a voltmeter, and you watched how much the voltage drops as you draw current, getting a feel of that. As the battery gets toward its depleted point, the voltage drops quickly with increasing current. It's like when you start a car and the battery is near dead, the starter turns slower, and so on. There were several cases where we just barely made it into a recharge point. In one case, we had a hill as we were coming to a recharge point, and we just crept up to the top of the hill, and then coming down, we were able to use the crude regenerative braking to gain five or six miles worth of range which we needed to get to the recharge point. There were several cases where it was—talk about range anxiety. I mean, we know what that means! [laughs]
This is Seligman, Arizona. Before we got there, we had to use the generator not once but twice. There was a map error. It was even further than we thought. And so we charged the battery with the diesel generator to put in what we thought was enough amp-hours, and it wasn't, and we had to do a second recharge. The charging with the diesel generator was slower than the recharging with the electric utility. Finally we got to Seligman, Arizona. We were now a couple of hours later than we had hoped to get there. We thought that the problems would be behind us. This was the longest lap of the race, to speak. We start charging—the power came from a—there was, I think, wires brought down from a pole. We connected to those. Oh, after about seven minutes of charging, the power went off. We had blown a fuse. But it was not a secondary fuse; it was a primary fuse that took out an area—there were several businesses that were in the dark, and people coming out mad [laughs]. The utility replaced the primary fuse and I was able to charge at a lower rate. After charging for about half an hour, the same thing happened again, so they replaced the fuse a second time. Now, we charged at an even lower rate, and more time was lost. I was thinking, well, maybe this was the worst that's going to happen. And the worst was yet to happen. About ten miles out of Seligman, Arizona, I was driving. It seems all the bad things happened when I was driving.
RIPPEL: I was driving, and there was this little downgrade, and an opportunity to use the regenerative braking. I was in third gear at the time, and I figured I would downshift to second gear. I knew that the motor would get up to about 4,000 RPM. It was rated for that. I had done the math. I downshift, and a few seconds later, there's a tremendous thud, and the car quickly decelerates. The follow car had to hit the brakes so that it wouldn't run into us. What had happened is that the motor blew up. The centrifugal loading on the motor was more than the banding could take, so the motor blew up. When it blew up, the clutch acted as a brake. The clutch slipped. If I didn't have a clutch, if it were a direct connection, I would have probably destroyed the transmission. When I realized what had happened, I figured that there was no chance for us to continue in the race, because we'd have to get a new motor. There were holes that have to be drilled in that motor for the mating, the housing adapter. Then the work of shipping that and everything, I figured that's—
ZIERLER: It's over.
RIPPEL: "Let's call it quits." Dick Rubinstein, who was one of our follow car members—and he was the one very proactive trying to keep us on track doing things efficiently, and we had already started hating him, because he was [laughs] always telling us how we could do things better—he said, "We're going to fix this, Wally." He said, "I know the rules as well as you do. The rules allow us to push the car without penalty." He said, "Pushing the car from here to Boston is going to take more than a month." He said, "I think that's a bad idea." He said, "We're going to fix the car. You're going to get a new motor, and we're going to fix it, whatever it takes."
One of the follow cars drove me back to Seligman, Arizona. I had a lot of quarters with me for—we didn't have cell phones then—and I called Electric Fuel Propulsion, where we had gotten the original motor. The person there had just broken his ankle, but he had some people that would help him. He said, "Well, we'll get another motor created up and sent to you." He figured approximately what he could. We'd have to coordinate a little bit with the flight scheduling, when the flights would go out of Detroit to Phoenix. Just before I was to hang up the phone, I said, "Bob, the motor has this weird shaft. It's a square shaft that I had to adapt to." I said, "You're still using that, aren't you?" He said, "Oh no. About six months ago, we went to a round shaft with a double keyway." I realized that things aren't going to work. He said, "But what I can do is I can take this over to a local shop. We have one of the square shafts. Take the motor apart, put the new shaft in, recreate it, get it sent to you." I said, "Well, okay, but I still have a problem. I'm going to have to do some machine work on the motor when we get it."
He created it up, sent it to the Detroit airport, got it on a TWA flight. Meantime, I was able to con my way into getting a university to allow us to use their machine shop. Now, think of this in terms of insurance. We're going to be taking a 200-pound motor, putting it on a mill bed to drill some holes in it and tap that, and if someone gets hurt, what happens then? I talked to the machinist and he said, "Yeah, you come in, be careful" and he let us come in and do this. Northern Arizona University machine shop.
All of that had to be coordinated, the logistics. Middle of the night, the motor was picked up. It was shipped from Detroit—the flight happened to work out—to Sky Harbor Airport at Phoenix, was picked up there, and then driven 70-some miles or whatever to where the machine shop was. They got in early, something like 7:30, so we'd be able to do this. George Schwartz did all the machine work and everything, got everything with the holes right and so on. I then went to the machine shop, and from there we took the motor back to where the car was. As we were driving back, we rehearsed how we were going to put the motor in the car. At first, someone said, "Well, we'll just put it in the way we took it out." "No, no. We've got time now while we're driving; let's do this in detail. Who has the 7/16th inch wrench? Okay, Ron, you have the wrench. Who has the thing we're going to use for lifting the motor? You have that." And we go through this. "No, that's not going to work, because we're getting in each other's way." We went through this about three times. The net result was when we got to where the car was on the roadside, about seven miles out of Seligman, Arizona, it took us only 15 minutes to get the motor put in the car.
RIPPEL: That was another aha moment. I realized what can be done when people work together. I had been weak in that, and without the extra people, without Dick Rubinstein and others, it would have been impossible.
ZIERLER: This is a lesson in teamwork for you.
RIPPEL: Yes, yes. This was something that I was weak in, and it was a very powerful lesson, that if you want to get things done—you may spearhead it, but you need other people.
ZIERLER: How much idle time was this, total, with the motor breakdown?
RIPPEL: This is interesting. From the time the motor failed—we kept track of that—until I flipped the switch and we were back on the road again, was 23 hours and 30 minutes. That included all these things—the motor being taken apart, the new shaft being put in, the motor being put back together, being crated up, taken to the airport, being shipped, being shipped from the airport to the machine shop, being worked on at the machine shop, being transported from the machine shop to the roadside, and then installed in the vehicle. All of that was 23 hours and 30 minutes. If it would have been 24 hours, we would have lost the race.
RIPPEL: So that was an interesting experience for me. I learned something there.
ZIERLER: Did MIT have a similar kind of crisis?
RIPPEL: Oh, yes. Of course at this point, we were now behind—we had been running behind, and now we had lost a day. MIT was doing great with the 200 pounds of ice. It really looked good for them, and we knew that MIT was going to win. In a way, I was glad. It was looking good for them, and we have a real race. We realized that there is always the possibility that something bad would happen on the MIT side. Well, before something bad happened on the MIT side, something else bad happened to us. We got into Amarillo, Texas. We were charging at a post office, the U.S. post office, and it was about 4:30 in the morning. It was dark, 4:00 to 4:30, somewhere in there. I remember seeing these great big busbars that we were connecting to, 208, three-phase. It was probably a 1,000-amp capability. The charger was what is known as phase rotation sensitive. There are two ways you can connect the wires, the right way and the wrong way. [laughs] A 50% probability. If you get it connected the wrong way, when you turn the firing circuit control, to a certain point, you'd hear a certain sound, and you'd back off and switch the wires, and that had worked before. Well, I was a little tired, and I got to this point, and I didn't hear the sound. I should have known better; I kept turning the control more. All of a sudden—I mean, it was like a bomb going off—I saw a tremendous flash. I could see where we were for the first time. It was like a flash picture of the postal area. What had happened is a current surge took place which caused the diodes to fail in a shorted mode. We did not have proper fusing. A tremendous current surge then ensued, which physically yanked these great big 200-amp alligator clips, yanked them off of the busbars, drawing an arc as they were thrown off. If I would have seen that in a movie, I would have said, "That's completely impossible. Magnetic forces aren't going to do that. It takes thousands of amps to do that." But it happened. George Schwartz was struck in the back by one of these clips. It didn't hurt him, but it surely alarmed him.
Well, now I knew what I had to do is to replace the diodes and make sure I don't make this mistake again with the phase rotation. I knew what had happened. There was one problem, though; the diodes were in the follow car, and the follow car had gotten lost, the only time they got lost. I got on the phone to the Highway Patrol. I called up the Highway Patrol, told them what's happening, and I described the car, and I said, "Can you escort this car back to where we are, at the Amarillo Post Office?" And they did. I don't know if we'd be so lucky nowadays. [laughs] They came in. It was another hour and a half or so lost. I put the new diodes in, and things worked. That was our last major problem, but unless MIT made a big mistake, we knew we were going to lose the race. Things went on, and we were now struggling just with ourselves. We were tired, and staying awake, and checking on ourselves so we wouldn't make any mistakes. We had another 1,200 miles to go or something. I forget exactly what it was.
When MIT got to Amboy, California, they were only three charge points away from Caltech, and they had a similar problem with their charger. They blew up their diodes. I don't think it was so spectacular. I think they were smart. They had proper fusing. They replaced the diodes, and the same thing again happened. They concluded that there was something different with the recharge point, that there was a transient or something. They figured that the best thing they could do would be to tow to the next recharge point. They knew they were going to win the race. Tow to the next recharge point rather than put the last set of diodes in and have that fail and then they couldn't do anything. That was a rational decision they made. But they made a mistake. They left the car in first gear, and they didn't have a clutch, and when they towed, they went 80 miles an hour.
ZIERLER: Oh, no!
RIPPEL: Long before they got to 80 miles an hour, I know that the car—the motor had blown up. When the motor blew up, they tore out the transmission, because there's nothing to absorb that. They got to—
ZIERLER: That's a bigger, catastrophic problem than you had.
RIPPEL: Oh, yes. They got to the recharge point without a motor, without a charger, and without a transmission.
RIPPEL: They knew that the time that it would take to fix those would definitely be more than the penalties they would get in towing the rest of the way to Caltech, so they towed the rest of the way to Caltech, and they towed across the finish line. I think my last picture here is of the MIT car, towing in. Where do I have that? Yeah, here it is. Corvette, towing the MIT car into Caltech.
ZIERLER: Oh, my.
RIPPEL: They were demoralized. They didn't know whether they were going to tow or abandon the car or something. They were very—and of course, the finger-pointing—I felt sorry for them. I realized the same still can happen to us. "Don't gloat." So we were extra careful. Dick Rubinstein said, "You're still going to lose the race, even with their penalties and everything." He said, "You've got to pick up—the only thing you can do is shorten charge times." I had been charging at a little bit below the maximum rate of the charger. He said, "Your charger was designed to work in the desert. Now we've got reasonable temperatures. Do the calculation. Figure what you can push it to. In the worst case, your charger fails and you have to do something, but you may be able to get diodes put in. You'll still get to MIT. But let's make an effort to try to win the race." I was just tired. I was thinking, "Dick, I just want to get to MIT and find a bed to lie on. I'm just dead. I can't do this anymore." He kept us going. He was amazing. Without him, we definitely would have not won the race. [laughs] And he wasn't getting any positive feedback We just hated him.
ZIERLER: What did it feel like when you crossed the finish line?
RIPPEL: Relief. It was more relief than victory. I remember the other members of the team, they wanted to find a place to lie down and sleep. I met with the press, and I don't know if I said crazy things. I was pretty worn down. Initially, with all this, MIT still had won the race, when they did the calculation. Machine Design had a formula that used the start time and the finish time, the local times—there's three hours' difference—and then it corrected for the time difference. But the way their formula was structured, you needed to enter that three hours twice, and they entered it only once. When they entered it once, MIT was ahead by two, two and a half hours or something. Then they caught the mistake, and it turned out—so first they released some information to the press that MIT had won. Then they corrected it, that Caltech had won.
Now, what was interesting is we were so worn out—I think everyone was asleep while this was happening, because they were so tired. I think I was asleep when the news came, and when I woke up, I heard that in fact we had won, and that was great news. Then the president of MIT did something interesting. We had originally been put up in the men's dorm, and when he realized that Caltech won, he moved us to McCormick Hall, the girls' dorm [laughs]. It was all vacated. It was still summer. Just the symbolism of that was wonderful.
ZIERLER: Despite the technicality in terms of the calculation, what about just the fact that you guys got to MIT on your own four wheels, and MIT did not?
RIPPEL: Yes. Well, this was very important, and it was kind of a badge of honor. We wanted to be the first electric car to cross the country fully on electric power, and we did, with the exception of a few feet where we pushed the car when we were working on the motor thing. But other than those few feet, it was all electric power.
ZIERLER: Last question for today. To go back to that history class, where you thought about the pronouns—what can they do, what can we do, what can I do—when you recovered from this race, how did that change your thinking about what you could do?
RIPPEL: Well, that was interesting. As I said, I learned a lesson. The lesson I learned is you can have a seminal idea, you can have an inspiration, and that's good, but it has to be backed up with other people's effort. That was an important lesson. See, I had been brought up kind of to be the rugged individualist. You could see me doing the machine work. There was some stuff that I got help with. I didn't know how to weld, so there was some welding that had to be done that was done here at Caltech. But I tried to be as much hands-on as possible. I learned a lesson. I'm not sure I've fully utilized that over the years, but I definitely know it in my head.
ZIERLER: With that, we'll pick up for next time.
[End of Recording]
ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is December 16th, 2021. I am so happy to be back with Wally Rippel, Wally thank you for joining me.
RIPPEL: It's my pleasure.
ZIERLER: I'll start with a prosaic question—after the race and you find yourself in Cambridge, what did you do with the VW Bus?
RIPPEL: Directly after the race, I was invited to participate in a Washington DC expo dealing with transportation. The VW bus was transported from Cambridge to DC at the expense of VW of America. In DC, we joined a number of vehicles which were on display around the Washington mall. I remember driving several laps around the mall with passenger guests - some of whom had impressive titles. After Washington, the bus was transported to Ithaca, home of Cornell University where I used it for daily transport during my graduate career there.
ZIERLER: This is a true statement of the possibilities of EV, that you didn't just kill it cross-country, that it was still a viable means of transportation.
RIPPEL: It was. But it was interesting; I had a minor accident where there were some dents put in it. As a result, I did not transport it back to California. I left it at Cornell University. I had set up an electric car lab there, and I thought I'd donate it to them, and they'd be able to use it as a test bed or something. What they did was they junked it. They got rid of it, shortly after I left.
ZIERLER: Oh no!
RIPPEL: My mom was furious. She had told me many times, "You should have donated that to a museum or something."
ZIERLER: I know. That's what I was going to say.
RIPPEL: My thinking was so off. [laughs] I remember telling my mom, "Well, there were so many flaws in it." [laughs] Later on, I thought yeah, there were so many flaws in the Wright Flyer, and stuff. The flaws now, I look back, they would be the things that you'd value.
ZIERLER: As a college kid, did you appreciate at the time the historic significance of what you had accomplished?
RIPPEL: It's interesting; I didn't, as much as I could have. This is kind of the thing of myopia. I was aware of the design defects in the vehicle—"I could have done this better and that better" and so on. I looked at that from a point of a negative. I saw it that way until maybe 20, 30 years later, and then I appreciated its significance. One has to remember, in 1968, electric vehicles were viewed as the least likely alternative.
ZIERLER: But people were talking about alternatives.
RIPPEL: They were talking about alternatives, but most of the talk was variations of the internal combustion engine and diesel to some extent. The view of electric vehicles as any potential mainstream vehicle was not at all there. It's only recently that we've gained a vision for that. Even after the EV1, that vision was still not there. It's only after Tesla has done things that people see it now as a future. I'd have to say the lithium ion battery was the main thing that changed it. Of course the lithium ion battery wasn't even a dream at that time. A lot has changed. At any rate, I used that as my transportation during my graduate years. There was the first Earth Day, and I was present with the VW with that, on campus.
ZIERLER: Let's rewind back to Caltech to get a sense of your aspirations for graduate school. First, what kinds of programs in graduate school were you looking at?
RIPPEL: I was looking to do work in quote "batteries and fuel cells" but from a physics point of view, rather than an electrochemistry point of view. That's what was in my application to Cornell, and they seemed to like it. My goal was to be able to do some things where I'd be applying my physics background to further energy storage. The battery thing is interesting; I was thinking about it this morning. There's kind of a thread that goes through here. Going back to when I was a student here, I had a thermodynamics class with Hans Liepmann. I may have mentioned it last time. I had that opportunity to teach a class, one class on batteries, and I didn't feel that I could pull stuff together that gave me a comprehensive understanding, so I passed on it. Then when I went to Cornell, the idea was I would be working in batteries and fuel cells. I met with my advisor several times and I just couldn't get anything even over the horizon identified, so I switched from physics to EE. I was a TA in both cases. I enjoyed the academics of physics more than engineering, but I felt more at home in the electrical engineering because of the things I had done, and just it was easy for me to see where I could make some progress.
ZIERLER: That was your degree at Caltech, was in EE?
RIPPEL: No, my degree at Caltech was a BS in physics. But at Cornell, I was going to get a PhD in physics, but my thesis would have been directed towards something in connection with batteries and fuel cells.
ZIERLER: But at Caltech, you were more on the applied physics track.
RIPPEL: Yes, yes. As an undergraduate, you're taking certain classes, so I still had the opportunity of whether I was going to be an experimentalist or a theoretician. I think I concluded fairly early on that if I were going to work in physics professionally, I'd be working in the experimental or the applied side. I liked it. I had more abilities there. I came to realize, theoretical physics, to really make a mark in it, you have to have some talents that I didn't have.
ZIERLER: Well, if you're hanging out in a place where you have people like Feynman and Gell-Mann, that sort of raises the bar.
RIPPEL: Yes, yes. Very true. That is both inspirational and also scary.
ZIERLER: Where else besides Cornell did you apply or was there something specific about Cornell that that's where you really focused?
RIPPEL: I only applied to Cornell. I liked Cornell because of the rural atmosphere, the countryside, and they had a solid state physics group that I thought would be applicable to what I wanted to do. I thought of applying to MIT but I didn't. So I [laughs] lived dangerously. And I say that because at the time, with the Vietnam War, you were either in school or overseas.
ZIERLER: Cornell also has a strong engineering physics program. Was that something that you were thinking about also?
RIPPEL: At the time, I was not aware of that, as such. I was aware mainly of the things in connection with solid state physics. I felt shortly after I came there that what I wanted to do was kind of a maverick thing. It was not any part of anything that they had a vision for. That became discouraging.
ZIERLER: What year did you start at Cornell?
RIPPEL: I got there in 1968. The race was August, and early September. [laughs] It sounds so funny, talking about a race, spanning two months. [laughs] So yeah, I got started then.
ZIERLER: Coming from Pasadena in 1968 where relatively speaking, the campus was quiet and was largely apolitical, what was it like on campus when you got to Ithaca?
RIPPEL: Oh, that was very interesting. This was really at the peak of some of the student protests. We had the SDS, Students for a Democratic Society, that were very active. I had been brought up in a conservative environment. The Vietnam War was supposedly a good thing for standing up to the communists. So for me personally, there was the tension created. There were some pretty extreme things that occurred while I was there. A group of students, including the SDS, took over the student union with live ammunition. It was on the cover of I guess TIME magazine. I couldn't understand why the faculty and the president were allowing all of this. Potentially something could have happened where people would have gotten hurt. Later, I found out that the SDS had done a little research on the president of Cornell, and they found some skeletons in the closet, and so they were able to take advantage of that. I got really discouraged—and the feeling that the campus was about to blow up—so I put a phone call in to someone I knew, Lee DuBridge, who was then Richard Nixon's science advisor. I thought, "There's one chance in a thousand that I'll get through to him." But I called the White House.
ZIERLER: Did you know Lee from Caltech?
RIPPEL: Yes. As I mentioned last time, it came about to some extent through my parents, who were part of the then Service League organization. He was a very approachable person. The fact that I got to know him, I don't give any credit to myself, because he would reach out, whether it was a person with two Nobel Prizes [laughs] or someone who was working in the janitorial staff. He treated people as people.
ZIERLER: And at a small enough place like Caltech, you can do that? You can have those relationships?
RIPPEL: Yes. Well, you can also not have them, but he elected to have them, and I have a very high respect for him. At any rate, I called the White House and told who I was, and within a moment, I heard, "Hi, Wally, how are you doing?"
RIPPEL: I told him what was happening at Cornell, and he said, "Yeah, I know all about it." I said, "I'm going to ask you—is this a place I should stay? What do you think?" He said, "Wally, in about a week, your school is going to have a new president, and things are going to settle down and be pretty nice." And in about a week, we had a new president.
ZIERLER: What did he know?
RIPPEL: That's exactly right. He was privy to information that the rest of us weren't. I often wondered [laughs] what all was behind the scenes there. Partly because of that, I calmed down. I remember there was an April 1st—we had a student newspaper, and there was one of these lampoon articles about the SDS [laughs] wiring one of the bridges to blow it up [laughs] on campus. And I'm reading this, and [laughs] for the first five minutes, I'm believing it. It was a window on myself, of how I had gotten so wound up in seeing the politics in it. It was a lesson to me, personally, how to calm down and look at things in a little bit more humorous way.
ZIERLER: As I'm sure you know, Alan Cocconi was insistent that he would never be involved in any technology that would be coopted by the military, for example. For yourself, were you thinking along those lines about military applications, what you'd be willing to participate in, what not?
RIPPEL: Alan is an unusual person, and I deeply respect him. I was not at that point nor am I at that point. I have what you'd call a more moderate point of view. People talk, for instance, in one sense, about "defund the police" and my feeling is "fix the police." It's a more moderate thing. I see defects. You will need police. You will need a military. The issue is, how do you run it and what are your values. But on the other hand, I respect Alan's point of view. When you look historically, you realize that military and technology have often gone hand in hand. You go back to Archimedes and others, and you see that, and you realize that it would be better if we could use our brains and technology more constructively. You look during World War II, and we did amazing things that we haven't been able to do since. In some ways, war brings out the—I'm not going to say best, but it definitely—
ZIERLER: There's an urgency to produce.
RIPPEL: Yeah. And I'd like to see us have that same urgency in connection with climate change. Both of them are somewhat of an existential battle for survival.
ZIERLER: That's right.
RIPPEL: The nice thing about climate change is you don't have to kill people.
ZIERLER: Except if you do nothing.
RIPPEL: Good point. Well, then, you're the victim, of course.
ZIERLER: In terms of your professional aspirations when you got to Cornell, were you thinking about the great electric car race as the first step in a career in alternate forms of transportation?
RIPPEL: I think my vision has been ever since my sophomore year for electric vehicles. There may have been a few moments where I wavered slightly in terms of would it be batteries or fuel cells, but I came back quickly to batteries. I seriously wanted to contribute to the energy storage thing. That was how I envisioned myself initially. Then the turning point at Cornell was not being able to put something together. I had some attempted starts, and I discussed that with my advisor, and it didn't look too promising. To continue my academic career at Cornell, I switched over to EE, and I got support for an electric car lab at Cornell. We set up a dynamometer and we built stuff and it was all engineering.
ZIERLER: I wonder if you can explain what a dynamometer is.
RIPPEL: A dynamometer is the equivalent of a treadmill. If you want to see how your heart is working, you get on a treadmill, and they up the grade or whatever, until you yell "Uncle." When you build a drive system where you have a motor or a gasoline engine, electric motor, whatever, you want to know how it's going to work, and you don't want to go through the complexity of putting it into a vehicle and where you're far away from the lab. You have the equivalent of a treadmill, where the motor is operating into something that's a load, that produces a resistance to its operation, and you're in an environment where you can acquire data and you can fix things and modify things as you want to. That's what a dynamometer basically is, and you build a laboratory around it with other ancillary equipment, your test equipment.
In those days, recording data was a big deal. Today, you use your laptop computer and you can record all sorts of stuff, and after you have the data, you can do all sorts of things with it. In 1968, you'd use things like pen recorders, the type of recorders we see for earthquake monitoring. You'd have a chart, one representing voltage and another current and speed and so on. Then you'd tediously go through and you'd figure out what the power was or what the efficiencies were. Or you'd have to transfer it to cards or something, for running it into a computer. So manipulating data then was very awkward compared to the way it is now. It gives one great appreciation for the present.
ZIERLER: Was the central focus of your research on batteries?
RIPPEL: No. It would have been. It was motors and the power electronics, especially the power electronics. That's something that I took a liking to, and I had some talents in it. Even at Cornell, I got a couple of patents on things, things that long since have been useless and obsolete. [laughs] I focused on the power electronics and a little bit on motors, and then later, more on the motor side. I took a couple of classes dealing with motor design at Cornell. In terms of the power electronics, at that time there was really nothing at Cornell. There was an oral exam I had in connection with my master's thesis. I felt I was helping the faculty to ask the right questions.
ZIERLER: Because you were further ahead than they were?
RIPPEL: I think so, at the time. Yeah. But often I'm sure when you interview people you hear all the success stories of what they've accomplished. Since electric vehicles for whatever reason now are really a success or moving in that direction, I also want to point out where I've fallen short, and that was in the battery area. Going back to my junior year, I had an opportunity to—maybe had I taught that class, I would have gotten more involved academically. I had the opportunity at Cornell University, if I would have perhaps been a little bit more insistent and persistent, I would have gotten something going in the PhD area. I pulled away from it.
ZIERLER: What does that tell us, though, about the fact that lead acid was really the only thing to work with, at that time? How dynamic was the field, really, at that point?
RIPPEL: The problem was, if you were going to do anything of any note in batteries, it was empirical. It was not something that connected to physics. Over here, you have the realm of physics where you're dealing with some of the fundamental equations. Then there's a big gulf between that and what people were doing with batteries. The application of physics to batteries was very superficial at the time. It's still not what it should be. I believe when it gets lined up properly, I think we will start to make greater progress, more rapid progress. Now, here's what's interesting. Toward the end of my stay at Cornell, I was invited to come back to Caltech in the chemical engineering program and get my PhD in chemical engineering, doing what I wanted to do, in connection with batteries and fuel cells. I jumped at it.
ZIERLER: You finished with the master's at Cornell?
ZIERLER: Were you on track to go on to the PhD and you cut that short?
RIPPEL: At Cornell? Yes. I didn't want to stay at Cornell. I wanted to go some other place. With the opportunity here at Caltech, I thought, "Yeah, that's good." I probably should have done a better job of discussing with a couple of professors who invited me what exactly I'd be doing, to avoid a repeat of the problem at Cornell. One of the professors left, and another was killed in an airplane crash. I was then somewhat on my own, and after a couple of quarters, I just gave up and left. Twice, I'm a PhD dropout. [laughs]
ZIERLER: Were you recruited back to Caltech? Were you looking around, and that was just the best option?
RIPPEL: No, I was recruited. I was contacted. It was interesting.
ZIERLER: Who was driving that recruitment?
RIPPEL: Fred Shair was one of the professors involved, and Professor Leal [?] or Professor Vaughn, I don't remember who, was the second one. My memory is a little short there.
ZIERLER: They were in chemical engineering?
ZIERLER: What does that tell us about both chemical engineering and what you were doing in power electronics? Because I would think you would come back in EE here.
RIPPEL: Yes, I know. Well, there was this side of me that wanted to get back and do something in batteries, because I felt this was the important thing. I knew that there would be progress in power electronics whether I did something or not. I took the easier road for me personally. I think that it was taking the easy road when I dropped out the second time here at Caltech. I didn't see a pathway for making something happen. I got discouraged. I'm sure I'm not the first person that that happened to.
ZIERLER: Did you ever interact with Carver Mead? Were you following what he was doing in integrated circuits?
RIPPEL: A little bit. I spoke to him during my undergrad period here. I think it was he that I asked the question of. I said, "Is that possible to make a high-voltage transistor? If I had that, then I could make a good speed control [laughs] for an electric vehicle, and other things—inverters and stuff." He said, "Well, you can make a high-voltage transistor." He asked me what I meant by high voltage. I said, "I'd like something at 600 volts." He said, "Well, yeah, you could do that." At the time, the highest voltage rating on transistors was maybe 100 or 120 volts. But he said, "You wouldn't want it." He told me all the trades you'd make to get to the high voltage would cause—the speed of switching and everything would be slow, and other problems would occur, so you wouldn't want it.
Now, what was interesting—he was completely right about the tradeoffs. But at the time, he didn't realize how good things could get if you had the fabrication technology to make the ideal transistors. It took a long time until people realized how good it could get. Then it got even better because we learned, instead of making a bipolar transistor, we used the field effect, which was a little new thing, and it meant you could control it much easier. Then it got better yet with the IGBT, where you combined the transistor with the field effect transistor, the two different versions. I had worked, when I was at JPL, on technology kind of doing that. I was very close to re-inventing the IGBT.
I did a number of things. I have a number of patents dealing with power electronics. But I missed the thing with batteries. I had other opportunities. Coming back to Caltech was not my last opportunity. After I dropped out of the PhD program here at Caltech, I worked for about a year in a company building power supplies. Then I became part of the technical staff at JPL.
ZIERLER: Just to interrogate a little your motivations at that point, instead of being hard on yourself about dropping out of the program, maybe at some point you realized that going for the PhD would lead you down an academic path, and that's something that simply didn't appeal to you? You wanted to be in industry. You wanted to build stuff.
RIPPEL: Yeah, I liked building stuff. But I also recognized—I guess I valued both. I felt especially with batteries, we needed to create a theoretical basis, which would likely come from academia. Industry was, especially at the time, you had lead acid batteries with small profit margins and no money available for R&D. Even if you did R&D, it wasn't clear what you were going to accomplish. Batteries never would have become what they are without the tech industry. They needed something, and they had money, so they parlayed the lithium ion battery into the battery that we see today. It started out pretty poor. A lot of work had to be done by Sony to make it what it is today.
ZIERLER: What was the timing of the inclusion of catalytic convertors on automobiles, and understanding that this would be a major solution to the smog problem in Southern California?
RIPPEL: That's interesting. The catalysts came in the 1970s. This is very interesting, because it shows an area that I didn't appreciate. I did not think that it would be possible to clean the gasoline engine up by the large percentage that it was done. I thought they'd get a factor of two or three but not a factor of 50 or 100. It worked far better than I expected.
ZIERLER: Maybe that retarded interest in electric vehicles to some extent?
RIPPEL: Oh, absolutely. The next interest level was not based on pollution but based on the 1970s with the energy crisis.
ZIERLER: How long did you stay at Caltech in the PhD program?
RIPPEL: It was just a couple of quarters. I also felt the courses I was taking, there was a side where I thought, "I'm being trained to be a petroleum engineer." That's the last thing I wanted.
ZIERLER: That's going the wrong way! [laughs]
RIPPEL: A little bit of that would be good, and I had a class in thermodynamics and reactor theory. I thought, "Some of this will be applicable." But at some point, seeing that become the center of mass rather than the things with electrochemistry and what I wanted to do.
ZIERLER: Was there a phase two of the VW electric bus project that you were envisioning at that point?
RIPPEL: What I did do, after I left Caltech, is I spent a couple of years, and I built another electric vehicle. I converted a Datsun 1200, which I used for transportation. It was better than the VW Bus, and it was still lead acid-powered.
ZIERLER: Tell me about the 1200. I'm not familiar with that model. I know the Z. That's my go-to for the Datsun.
RIPPEL: It was a small vehicle, a four-seater, with a stick shift transmission originally. Were you familiar with a 510? This was actually a little bit smaller than the 510.
ZIERLER: It's a small sedan?
RIPPEL: Yeah. It had almost the same mass of battery as the VW Bus, so I had to do work on the suspension and so on. It worked pretty well. It was definitely acceptable for transportation around Los Angeles. It had about a 70-mile range, and a little over 60 miles an hour top speed, so it worked on the freeway pretty well. But it was still nowhere near where it needed to be for a product.
ZIERLER: Between your own technical skills and advances in technology, were there obvious places where this was a step up from the VW?
RIPPEL: Oh, yes. Now, when I worked at JPL, that vehicle was used—we did a lot of testing on the vehicle as part of the DOE program, to evaluate electric vehicles. It came out on top. There were about seven or eight vehicles that the Department of Energy tested, and this vehicle was the best in terms of range, acceleration, and so on. It was still nowhere near what I was hoping for. So it was something that kind of combined into my early work at JPL, when I was first there in 1976.
ZIERLER: Now, push and pull factors—the initial job you had before JPL, was this something that was sufficiently attractive that it pulled you out of the program? Or you left Caltech and you were looking for your next opportunity?
RIPPEL: That job I got because I got married and I needed some income. [laughs] It was using my skills in terms of power electronics.
ZIERLER: What was the job? What was the company?
RIPPEL: It was a company called Autronics. It was in Pasadena on Vinedo Street. They made custom power supplies for all different things. I designed some power supplies, curiously, that were used on the Alaskan pipeline. [laughs]
RIPPEL: You know how that works. Then I designed a current sensor that was used in the Boeing 747. It was funny, because in the specifications for this, it was something that would end up weighing, I don't know, 60 or 70 grams, and they were very concerned about weight. I remember the senior engineer at Autronics said, "How can they care about weight? This is going in a plane that has a takeoff weight of more than half a million pounds, and they're worried about a few extra grams?" Of course, you do worry about it. Each gram represents, over the life of the plane, so many extra dollars of fuel. It's understood very simply, but the perception was that it was so strange that they were worrying about grams when you're building something for a 747.
ZIERLER: How long were you in this job for?
RIPPEL: That was just a year. Then something very interesting happened. This is now part of the electric vehicle history. We had this oil shock.
ZIERLER: This is 1974, after the Yom Kippur War.
RIPPEL: That's exactly right. I forgot that correlation.
ZIERLER: That's the Arab oil embargo when the Saudis stopped oil because the United States supplied Israel with the weapons.
RIPPEL: That's right. Congress appropriated $180 million for the so-called Electric Vehicle Act of 1976. You'll see that, if you look carefully at some footnote someplace, there's an asterisk someplace that will identify it, but it's something pretty much forgotten in history. Some of that went to JPL, and that was the basis of my coming on board at JPL.
ZIERLER: Oh, wow. And this was DOE funds, not NASA.
RIPPEL: That's right. It was complicated. It was from DOE to NASA or to Caltech, and so the funds were routed through a couple of interoffice or whatever agreements.
ZIERLER: Do you remember President Nixon's Project Independence initiative?
RIPPEL: Oh, yes.
ZIERLER: I wonder if this is sort of the legislative origins of that.
RIPPEL: That's very possible, yes. There's things that I should remember about that, that I don't.
ZIERLER: What were DOE's hopes and dreams with supporting JPL?
RIPPEL: The $180 million was appropriated to a number of laboratories. JPL was only one. It was split to several of the other government laboratories, Lewis Research Center and others, for two purposes. Mainly to get an assessment of where electric vehicles were at that point in time. A significant amount of work at JPL was to evaluate existing electric vehicles. The vehicle I had became part of that program. [laughs]
ZIERLER: The Datsun.
RIPPEL: The Datsun, yes. For over a month, my wife and I were away in Phoenix, Arizona, at a test facility, where there was a test track, and doing all sorts of testing. Range tests, acceleration tests, energy use, all sorts of things, and writing reports. It was fun, in a way.
ZIERLER: When we think of JPL, we think of satellites and planetary exploration. Why would they have been a recipient of these funds? Was it because of sensors?
RIPPEL: This is what's so interesting. Where was I at JPL? I was part of the electric power section, but I was in the group, the battery group, which was headed at the time by Aiji Uchiyama. Once again, I had an opportunity to be in the battery environment. I did a few things in batteries. I did some development work for an advanced lead acid battery. I inspired a couple of other people to do work in batteries at JPL, one of whom was Jack Roulette [?] who in turn linked up with Jeff Arias [?], and they formed a company, Arias Research, to do advanced lead acid batteries mainly for the purpose of electric vehicles. They accomplished some things, but financially, it was not a success. It was what I'd call a mild technical success and a business failure. Then there were some other people at JPL that got interested, one of whom was a Caltech graduate, and an important person—Dr. Dean Edwards, Caltech PhD, was in the electric power section. I got him interested, so his life's work became advanced lead acid batteries. He was at JPL with me for six years, I think. He left JPL, became a professor at University of Idaho, and his area of work for many years had been advanced lead acid batteries. I think the thing that brought that to an end was the lithium ion development.
ZIERLER: JPL was interested in batteries for—
RIPPEL: Spacecraft. And whether it was manned or unmanned, batteries were essential. You think of Apollo 13, the battery is what saved the day. They didn't have fuel cell power, and they were living off of what little energy they had stored in batteries, in silver-zinc batteries. So batteries have always been, right from—you go back to the Explorer 1, batteries were an essential part of the space program. The goal was to make better batteries for that application, and then also to develop, if possible, technologies that could be spun off outside of the space effort.
ZIERLER: I wonder if JPL was the best of both worlds for you, the intellectual environment of Caltech with all of the applications and opportunity to build that you had wanted to do.
RIPPEL: It was in many ways that. It had both the academic and the laboratory environment, which I liked. On the other hand, what was very frustrating was both at JPL and from DOE, a lack of enthusiasm and commitment for doing the electric vehicle stuff. I can understand with JPL; electric vehicles were not part of their mainstream interest. In spacecraft, you were talking about a couple hundred watts of power at most, for things. With electric vehicles, you're talking about two orders of magnitude higher power levels, so it's different technology, to some extent.
ZIERLER: This is because, in space, without gravity, you need a lot less power, I assume?
RIPPEL: Well, and most of the spacecraft stuff is for instrumentation, not for moving things. There were vehicles built during the Apollo - Lunar Rover—but the gravity was weaker, and the speeds were lower [laughs] so the power levels were very much less. It was a different thing. As I mentioned, when I was here, I worked with a grad student who was doing his PhD on control theory and all of that. We got support from JPL and all of that came to an end because of problems with funding.
ZIERLER: What came of the program? How well was the $180 million spent?
RIPPEL: I thought poorly. Yet there's another side, because I learned a lot. For me, it was a continued education. It was in that program that I started to do some serious thinking about what could be done with building drive systems, going back to first principles. I became somewhat of a theoretician working with the induction motor drive. It was that work that I did, and was allowed to do, that prepared me for what later became the Impact and the EVI. Without JPL, I wouldn't have had that preparation, so I'm thankful for it.
ZIERLER: How long were you at JPL?
RIPPEL: I started at JPL in 1976, and I was there until 1990. The only reason I left was to join AeroVironment, thinking that I was going to be part of the EV1 design team. Then shortly after I was at AeroVironment, General Motors said, "We are going to do this with a big wall around us." There was no longer—they didn't have consultants or anything. It was just GM. And I can understand that decision. It was rational.
ZIERLER: Fourteen years at JPL, there's so much to talk about. First, in 1976, what are some of the big things happening in JPL?
RIPPEL: When I first started at JPL, the Viking had just landed on Mars. It was an interesting period, because if you go back a few years before the Mariners, Mars was so much a mystery, you could rationally talk about there being the possibility of intelligent life on Mars. People thought that they had seen these canali form, and that there may be things going on with vegetation. It sounds almost strange to talk about it that way now.
ZIERLER: Now it does, because we know so much, but that's only because of JPL!
RIPPEL: Yes. Oh, yeah. The thing I find is you take some of this ambient knowledge for granted. As you move from superstition to science, you think, "How could we be so ignorant back then?" But you are ignorant until you learn something.
ZIERLER: That's where we are with exoplanets right now.
RIPPEL: Yes, yes. I remember a time when exoplanets were only a theoretical possibility. The only planets we knew about for sure were the planets in our own solar system.
EVs and Batteries at JPL
ZIERLER: Organizationally, where did you slot in originally at JPL?
RIPPEL: I was always part of section 342, the electrical power section. I remained a part of the battery group. I was brought in there because of probably knowing Aiji Uchiyama. That friendship developed during my days here on campus.
ZIERLER: Tell me about Uchiyama. What was he like?
RIPPEL: Very polite Japanese gentleman. He knew more about batteries than—I had to draw things out from him. He did not volunteer education for me. I enjoyed working with him a lot. He was a thoughtful, kind person.
ZIERLER: He had a joint appointment on campus, or he was only JPL?
RIPPEL: I think only JPL. Of course, there was the rest of the electrical power section, which was doing power electronics, and I got involved with that a lot. I had a little bit of involvement with batteries. I got involved with something—kind of an invention, bipolar battery. It became a quasi-bipolar battery using various materials. So I did some R&D work in batteries, and working with some other people. A couple of patents came out of it. Of course, when I look at this, in any way you look at it, it would be useless now. It was where you would make maybe at most a 30% improvement in range from what we had at the time with conventional lead acid batteries. As you know, when you go to a lithium battery, you're talking about a factor of six to ten better in energy storage. The mistake I made was taking a step back and working in things like packaging and not the fundamentals. I think that if I had pushed on it, I would have been able to do work on the fundamental side, where you're going back to the laws of physics, and not starting with what you observe with the active material used in conventional lead acid batteries. The givens would have been the Schrodinger equation rather than how battery materials function.
ZIERLER: When Carter came in, were there opportunities because of his interests in energy savings and alternatives to fossil fuels?
RIPPEL: Without Jimmy Carter, I don't think we would have done the things—DOE would not have been formed. DOE was a result of Jimmy Carter. It was a brief period where we had a vision. There's that famous speech of Carter where he said, "We will never use more foreign energy than as of this date." The idea was to at least start winding down our consumption of foreign oil. That did not happen, but Jimmy Carter got us started a little bit with using the metric system. When Reagan became president, we reversed that. Jimmy Carter put solar cells on the White House. Again, Reagan reversed that. It was interesting; I was still a Republican back then. I changed later, but—
ZIERLER: It was a very different Republican Party back then.
RIPPEL: Oh, it was a different Republican Party. But still, I was thinking, "Now, let's see. How does this line up?" [laughs] It didn't. The vision for energy was not something that Republicans had. The vision for energy really was, "Keep doing what you've been doing all along, and not anything new."
ZIERLER: The Iran hostage crisis didn't help things either.
RIPPEL: Oh, yeah. That caused me to feel frustrated with Jimmy Carter. I liked Jimmy Carter. I almost voted for him. [laughs] But yeah, I was discouraged with what happened there. I guess I like seeing solutions to problems and not problems that continue on for such a long time. What was it, 444 days or something? And it ended during the inauguration of Reagan.
ZIERLER: Yeah. After Viking, what was the big project at JPL?
RIPPEL: Well, there were a number of projects. I was involved in some small projects, things like the Lunar getaway Special, things that were—we started to think about things other than the really big projects, where we could do multiple things and have more frequent launches rather than a major project once every decade or so. Earlier, of course, we had launched the Voyager projects, and that was fascinating, the idea of wanting to communicate with somebody outside of our solar system, maybe even outside of our own galaxy. I was involved a little bit with the power supplies and stuff for the space effort, and I would say probably 20%, 30% of my effort was in connection with spacecraft, and the balance of my effort, which is where my heart lay, was with things related to electric vehicles.
ZIERLER: How did that work? Did the interest in electrical vehicles more inform the space work or vice versa, both in terms of you and in terms of what was emphasized at JPL as most important?
RIPPEL: That's interesting. I felt to some extent we were a little bit of an island doing the electric vehicle work. We went through a period where there was a shortage of space on lab, and so for a couple of years, I was at an annex location in Pasadena—Altadena and Foothill. During those years, I'd be on campus periodically, but there was a sense of isolation from the mainstream activities on lab. My interest was not in spacecraft but in the technology dealing with spacecraft. The semiconductors. It was during that time that the field effect transistor was brought into production.
ZIERLER: What is that, field effect transistor?
RIPPEL: It's a transistor where the field effect is used to turn it on and to turn it off. It has lower losses and is easier to control than the so called bipolar transistors previously used. It became the basic building block starting in the 1980s for power systems. Before that, it was the conventional transistor, kind of the transistor that was invented by Shockley, the bipolar transistor. The field effect transistor was faster, which meant you could operate at higher frequencies, which meant the power systems could be smaller and lighter. Very important for spacecraft. They had some vulnerabilities, radiation vulnerabilities, but they learned how to harden them. But that also became the basis for the power system used in the Impact. The Impact had—a spacecraft, you'd have maybe four transistors or something, as part of the power system. The Impact had 288 of the largest—then largest—field effect transistors to provide the inversion function, the changing of the DC to AC. So there was stuff going on at JPL that I was learning about, that helped me in many ways to be prepared for the Impact.
ZIERLER: The physics in space versus the physics on planet Earth, when you're thinking about propelling an electric vehicle, is it basically the same? Are there fundamental differences?
RIPPEL: In space, of course the idea of ion propulsion—there's power processing that has to be done where you take your power source, which may be a nuclear source or solar panels, and that is then converted into the appropriate voltages and currents for an ion thruster. So there's some areas of commonality.
ZIERLER: Now, I'll further break that down. Obviously the interface is so much different. In space, when you're dealing with manned versus unmanned spacecrafts, what are some of the things that you have to think about, in terms of dealing with power electronics, dealing with propulsion?
RIPPEL: The big thing in space which you don't appreciate if you work on terrestrial power, the biggest thing in space is radiation. Radiation potentially effects things like field effect transistors, FETs. They are vulnerable to that. You have to understand limits of—
ZIERLER: This is solar radiation we're talking about.
RIPPEL: Yes. There's also cosmic rays, and cosmic rays affect not only power components but they affect logic circuitry, so you have bit-flipping, and a computer can fail to function because of exposure to radiation. I think radiation is the main thing. There's other things that we take for granted. Air works well to reduce arcing at sea level, but when you build power electronics for where you go up to high altitude, 60,000 feet—and I've designed things like that—you have a lot of problems of corona discharge, of arcing and so on. Then it gets a little bit better when you get into the vacuum of space. Things are different in space, but the main thing, I think, is the radiation issues that you deal with.
ZIERLER: I'm thinking about the ice on the MIT car. What about temperature in space, both hot and cold?
RIPPEL: Military specs often are pretty extreme, -55 C to plus 125, and so you would automatically use components that are mil spec rated for those temperature ranges. The main problem of temperature is not with power semiconductors or semiconductors; it's with batteries. We see that here on Earth. The weak point in the electric car is the battery. When you get into low temperature, the battery will have less energy capability and so the range is less. The performance will be less. The life of the battery, on the other end, degrades when you get to the higher temperatures. If you go to Saudi Arabia, don't expect a Tesla to last as long as it would in California. At any rate, I was working on power electronics. I did a good deal of theoretical work learning what could be done with the induction motor. That was exciting. I realized that I could set much higher goals than originally. We got funding from both DOE and from EPRI to develop a complete drive system.
ZIERLER: What's EPRI?
RIPPEL: EPRI is Electric Power Research Institute. They were located near San Francisco. This was exciting to me because this would lead to a product, something that would be put in production and might even do a little bit of good. There were problems in the program, and to a large extent the problem was that in most of the engineering, I was doing all of the engineering. I was not complemented by other people that knew things that I didn't. I had a good friend at JPL, Dr. Dean Edwards, and he was doing more stuff on batteries, but I got him started on it. He was doing stuff on the bipolar lead acid battery. He was pretty enthused with it. He left JPL because he didn't see a product coming out of it. He wanted to see something with automotive companies or so. The work we were doing with EPRI and DOE, it wasn't clear that that was really going to lead to a product. We hoped it would, but there was no assurance of that.
ZIERLER: Where did the induction motor go? What was the application for that?
RIPPEL: The induction motor was invented kind of by Nikola Tesla and some others. It's one of the most common motors that is used. You plug it into 60 hertz of power, and if it's of one design, it will run at 1,800 RPM, or another design, it will run at 3,600 RPM. You don't have the ability to vary speed when you plug it into the wall, but when you combine that motor with an invertor, with power electronics, then it can be a variable speed motor, which is what you of course need for an electric vehicle. That combination of the motor and the invertor was the work that I concentrated on at JPL. Also understanding how the motor could be optimized to get higher power-to-weight ratios by better heat transfer, by higher speeds, by a lot of things. In the internal combustion engine world, one horsepower per pound of motor weight, at least at the time, was considered pretty respectable. I realized we could do much better than that with the induction motor. Even though when you go to Sears and you buy an induction motor that you plug into the wall, a one-horsepower motor would weigh about 35 pounds. So it was a different environment, and power electronics changed things, and so it was exciting to see how much power you could get out of a relatively small quantity of material. I was doing this work. The frustration was that it was only leading to reports. I have an example with me of one such report that was done at JPL on some of the invertor work I was doing.
ZIERLER: Who's the audience for the reports? Who reads these and decides what to do?
RIPPEL: These reports theoretically should have been the Department of Energy. But when you get to know people, and you realize the way it works, you'd be lucky if a few people read a report. It's submitted. They check off the funds were spent. It's filed. Maybe a few people in academia would read it. But so much work was done by the other laboratories, not just JPL, which is put on a shelf someplace. Now you can see it, because some of it is on the internet, but at the time—
ZIERLER: But what you're saying is you're writing these reports because you want to see the technology go somewhere.
RIPPEL: I wrote the reports because I had to. [laughs] That was the first thing. The money comes, and they expect something, and the deliverable was a report.
ZIERLER: But obviously, best case scenario, somebody in the right position reads the report and says, "Go do something with this."
RIPPEL: In the best case, yes, and that was questionable whether those best cases would come, even. I was hoping that there would be some opportunity to do something with this technology. In 1985, I heard about this company, AeroVironment, and they had achieved human-powered flight. This of course—you laugh at this as being a curiosity—pedal-powered flight. They even crossed the English Channel. Bryan Allen, great athlete, pedaling [laughs] and reaching the point of near exhaustion at the other side of the Channel. But I realized in order to do that, they needed to be good at aerodynamics and also building lightweight structures. I got in touch with AeroVironment and told them what I was doing at JPL, and I knew what they were doing.
Aerovironment and the Great Solar Race
ZIERLER: How did you first hear about AeroVironment? A news story?
RIPPEL: Just a news story. Reading the L.A. Times, I think. And thinking about that—wouldn't it be good if there could be a partnership formed? I got very limited approval from JPL, approval just to explore the possibility of doing something, but without any commitments. We explored the possibility where JPL would provide a drive system, and AeroVironment would bring together the rest of a vehicle, a chassis, body, to put together a demonstration vehicle, a demonstrator vehicle that could show, at that point, what could be done with electric vehicles. It was a lot more than anything the government had seen at that point. I had learned things about the drive system, and I think we were ahead on that from anyone else.
ZIERLER: Why the drive system? Why would JPL bring the drive system parts of this?
RIPPEL: Because that was the work I was doing. That was the EPRI-DOE thing. We knew that DOE would get some accolades, and EPRI accolades, if something came of that, with a car company, and JPL, likewise. There was a desire to have technology spun off for the public good. I met with AeroVironment and we discussed it. Out of that couple of meetings—I came there with Dean Edwards. Dean was doing the work on the batteries, and in the proposal that was put together, there was one appendix section that Dean put together, which was the battery capabilities, what they had done, what they had achieved, and so on. I had done the stuff with the drive system, the motor and electronics. Then AeroVironment put it all in context of what the vehicle would be. This would be a lead acid-powered vehicle. It would have a range of up to 100 miles, and would be fun to drive. The original goal was zero to 60 in ten seconds, which was at the time kind of unheard. I mean, getting to 60 miles an hour in an electric vehicle was challenging, but doing it in ten seconds was something kind of unheard of at the time.
ZIERLER: This was purely a terrestrial application. Nobody was thinking about space applications.
RIPPEL: That's right. I have a copy of a proposal here, if I get this number here right. Then I can open this. This is the proposal that was put together—
ZIERLER: Oh, wow.
RIPPEL: Electric Spirit proposal. It was submitted to General Motors in July of 1985, and I was really enthusiastic. I was enthusiastic because AeroVironment picked up pretty quickly. It was not a hard sell. They liked the idea, and I knew that if this was funded, that we'd get approval at JPL to actually do this stuff.
ZIERLER: Who were the key contacts at AeroVironment you were dealing with?
RIPPEL: I was dealing mainly with Paul MacCready, the founder of the company. Paul is a Caltech person. His background was in aeronautics.
ZIERLER: Did you know him previously from Caltech?
RIPPEL: No, I didn't. I first found out about Paul MacCready as a result of reading about AeroVironment and the human-powered flight.
ZIERLER: What was Paul like?
RIPPEL: First of all, he was someone who really cared about the environment. That's why the company was named AeroVironment—the combination of "aero" from aerodynamics and "vironment" from environment.
ZIERLER: Right. Good aerodynamics is good for the environment.
RIPPEL: Well, and—but they had a division at the time dealing with environmental remediation. They had several small groups; environmental remediation was one of them. Then they had a group out in Simi Valley that did stuff that was involved with unique type of small aircraft and things. I later on would be part of that. I was part of the effort for the Helios, where we set an altitude record with a solar-powered plane and got almost up to 100,000 feet. At any rate, we had this proposal. I was really disappointed when I heard that GM rejected it.
ZIERLER: Why the focus on GM?
RIPPEL: That's a good point. Paul MacCready had some contacts at GM. He knew some people at the design center in Newbury Park, which is where this was submitted to. His belief was that having those contacts would be a good starting point, a good entry point to GM. He did not have any contacts with Ford or anyone else to my knowledge.
ZIERLER: I wonder if there's a Tom Everhart connection?
RIPPEL: That came later. Yes, Tom Everhart was on the Board of Directors at a later time.
ZIERLER: Now, 1985, this is a five-year span before 1990. Were you thinking this might have been an exit strategy for you, from JPL, to join AeroVironment?
RIPPEL: No. As a matter of fact, I was thinking at the time the opposite, that if this comes real, there's going to be more funds coming into JPL to do what we're doing with the drive system, and we will be doing the fundamental work, handing it off then to a car company to productize it. My vision, at least at that time, in 1985, was that if anything, this would be further cementing my activities at JPL. And JPL, on one hand I knew that they didn't want to be distracted from their primary missions, of course. But I also knew that they wanted to do stuff where they would be viewed as doing things positive for the environment and society. As long as the work I was doing had that theoretical element, where it can go to any area—you learn how to make better semiconductors; they work in spacecraft as well as in electric vehicles. It all seemed at that point to make sense.
ZIERLER: What's the chain of command at JPL? Who are the superiors that need to be behind your work in order for this to succeed?
RIPPEL: That's interesting. Obviously the division head, and I'm trying to remember—Kirk Dawson. At JPL, I learned, you've got to get the political ducks lined up. Later, after, I worked for Aiji Uchiyama and then I later had Jim Graf. He has accomplished a lot at JPL. He has headed up some programs and so on. Jim was very astute at understanding the politics of you've got to communicate with people and get their buy-in on things, and he did that. I gave many presentations to many different division heads and stuff.
ZIERLER: Does this interest go all the way up to the director of JPL at the time, or that's too far up?
RIPPEL: That was initially Dr. William Pickering and then later - Dr. Bruce Murray. There was some level of support. It was not as much as I had hoped. I met a couple of times with some of the top people. I felt that they were telling me what I wanted to hear rather than what I needed to hear. So, it was mixed. I can understand that. The threat of all this was that you start to dilute your core competence areas and you get distracted doing things that you'd rather not do.
ZIERLER: To what extent is that structural, just because JPL, this is not the core of their mission?
RIPPEL: Their mission was the unmanned exploration of the planets, and they stayed true to that and tried to avoid things that would distract. The idea I had was that things that are at a theoretical level, as I mentioned, that apply to electric vehicles, would also apply to spacecraft. There was an area of overlap where everyone could feel like we were doing the right thing and not getting distracted. At any rate, we didn't have to worry about it too much, because the proposal was not funded.
ZIERLER: [laughs] What was your takeaway from that in terms of long-term prospects?
RIPPEL: I was discouraged. When you watch the movie Who Killed the Electric Car? this was for me the first major death of the electric car.
ZIERLER: Killed it before I started.
RIPPEL: Yeah, yeah. Then what happened next that led to something—to the actual pathway that led to something—was such a strange series of events. Now, you know I already had the contacts with AeroVironment because of this proposal, so they knew me. Alec Brooks, who was one of the managers at the time and an engineer at AeroVironment, he knew of me. Before I had come to AeroVironment, when he was in high school, he followed the Great Electric Car Race. He tells a story that he had kind of run home to listen to the news or get a newspaper to see what was happening with the progress on the electric car race. Alec was involved to some extent in the 1985 proposal that did not get funded. Here's what happened next. Completely out of the blue, in Australia, a person by the name of Hans Tolstrup who is an adventurer, a guy who had done a number of things—climbing mountains and things like that—a rowboat, he had literally rowed completely one lap around the continent of Australia. I mean, Australia is pretty big. [laughs] Now he wanted to do something that would call attention to climate change and perhaps would get some technologies started that would deal with the climate change problem.
ZIERLER: In the mid 1980s, the idea that the Earth was warming because of carbon emissions, this is just starting to come online.
RIPPEL: It's just on the horizon for people. It's interesting—when I was a sophomore here, I wrote a little article for the student newspaper, and I put a few words in about climate change. I was aware of it, I had heard about it, and I was parroting back what I had heard. But it was not viewed as an existential threat by any means at the time, and it was viewed as something that would—"Yeah, when the time comes, we've got to deal with this." A very different perception than we have now.
Tolstrup had a more alarmist perception than most people did, and he wanted to do something of significance. He put together the idea of a race, from the north to the south of Australia, along the Stuart Highway, from Adelaide to Darwin. It was 1,950 miles, I think. The rules for that race were sent out all over the world, and a copy of that ended up on the desk of Howard Wilson at the Hughes division of General Motors. Now, this was February of 1987, less than two years after the aborted proposal thing. Howard Wilson thought it would really be good for General Motors to enter into the race, and win it, of course, and they had the resources to do that. Spending a couple million dollars would not be a problem, and that would be more than probably most of the other people combined would spend. The only problem was he needed a skunkworks, something that could do things quickly. That didn't exist at Hughes or, to his knowledge, at General Motors. Howard Wilson had a couple of colleagues, one of whom knew Paul MacCready and suggested that he get in contact with Paul MacCready at AeroVironment. He talked to Paul MacCready about it, and they realized that the financial thing would not be a problem. The question was time. Paul was intrigued by it, and so he bought into it, so AeroVironment had the charter of basically developing what became known as the Sunraycer. Normally, they wouldn't have been able to do much in the area of propulsion. When I first met AeroVironment in 1985, they didn't have things like oscilloscopes or power supplies, so they wouldn't have been in line to do stuff for making a drive system for a solar-powered vehicle. But Alan Cocconi was on board as a consultant. The reason Alan Cocconi was a consultant at AeroVironment was because he had gotten fed up working for Caltech's Professors Ćuk and Middlebrook who had formed a company called, ironically, TESLAco. He kind of quit in a huff. Apparently someone was brought into the company to manage, and he didn't like the way that was going. Alan was a very independent kind of person. Alan's main interest was not electric vehicles; it was airplanes.
AeroVironment was kind of doing things in airplanes, all different things of small remotely controlled aircraft, things like that. Now, a project had come in for AeroVironment to make a replica of the pterodactyl, a bird that existed I think 60 million years ago. It was supposedly the largest flying creature that ever existed on the planet, with a wingspan the same as a Cessna. The goal was to make the wings flap so it would look like a real bird and not just a glider. That was Alan's job, was to do the power electronics, the drive system, to make the wings flap. It was a challenging project. Alan did that, and that work had been completed at the time Hughes went to AeroVironment and said, "Are you interested in doing something on a solar-powered vehicle?" Alan was available, and Alan was also needed. I was contacted immediately to work as a consultant and got permission, so I spent typically half a day a week, I think it was, where I'd be taking off from JPL, working as a consultant for AeroVironment, in connection with the Sunraycer project.
ZIERLER: Now, solar-powered propulsion, I assume this must have been of interest to JPL.
RIPPEL: Yes, except it was interesting: the communication never really took place along those lines. I could have initiated something, but I didn't. Part of it was that the solar panel was going to be done entirely by Hughes. Hughes was, as a matter of fact, perhaps in some ways a competitor to JPL in doing things with solar panels. Anything with a solar panel was going to come out of Hughes and definitely not JPL. But I could have still had some communications, because there might have been some lessons to be learned and things that would have been good. I did not take the initiative to provide those connections or establish them.
I worked with Alan in the Sunraycer project. It was a very fast-moving thing. What was interesting is at the time, people thought there was only one way to build a solar-powered vehicle; you want to have a solar panel that is a flat surface. That was the thinking. Then you can tip it so that it's just the right angle to the sun so you get the maximum power. Even though it looks ugly, you have this thing that's a giant postcard mounted on a vehicle. It would be efficient. The aerodynamic loss, people thought, would be very small, because it has this leading edge, which is just a very small rectangle, 100 square inches or something of frontal area. They didn't think that there would be much additional air drag caused by the solar panel. Paul MacCready understood that was not so, that people had a much higher penalty from these solar rays than they thought. So Paul MacCready wanted to have the solar panel curved and built right into the aerodynamic shape of a vehicle. Now, the problem doing that is it's a curved surface. It's no longer a flat surface, and different portions of that solar panel are going to be in different intensities of light. You have this cosine theta effect. If the angle is a 90-degree angle between the ray of sunlight and the surface of the solar panel, that's the ideal. As that angle moves away from 90 degrees, the amount of power you can extract from the sunlight reduces.
But it gets worse than that. You have these different parts of the solar panel that are connected together typically in series, and the power you would get would be limited by the weakest portion, where the angle was the greatest, where the sunlight was essentially the least. The immediate thinking that engineers had is this was the last thing you wanted to do. When AeroVironment proposed this to General Motors showing what they were going to do, the GM engineers immediately balked at it and said, "We know that's wrong. First of all, no one's doing it that way." They gave the explanations that I gave right now. But Alan was able to do something that compensated a lot for the problem. The solar panel would be broken into 12 segments, and each segment would be controlled separately, so that you extract the maximum power possible from that segment, and the nth segment does not limit the power that can be extracted from the first or any other segment. That meant building an electronic circuit, a power processing circuit, which had to be efficient, and also lightweight. Alan built a prototype of that in two weeks that was tested and worked wonderfully. It was very lightweight and very efficient, and it also had the controls so that it would optimally seek out—it would control so that the power was the optimal power. There is an optimal voltage and an optimal current that corresponds to optimal power for a given amount of sunlight, and you have to sense that in some way, because the sunlight is varying. Especially when you have clouds and so on, everything has to accommodate that. Alan did all of that with the controls in two weeks. It's the type of thing that you'd normally get a two-year contract to do! [laughs] That showed that the most critical part, the thing where there was the greatest question, that could be overcome.
ZIERLER: To go back to MacCready's insight on the aerodynamic aspect, did he intuit this, or was there wind tunnel testing where he arrived at that conclusion?
RIPPEL: He had done enough other things. What he knew was what they called a skin loss. He knew that the equation they were using was incomplete. The equation they used would be appropriate for an automobile, usually, where you have a large frontal area. But when you go to something that has a very small frontal area, which makes you think you're in great shape, then the rest of the surface becomes a significant factor. It was there anyway but normally that term didn't amount to much. In the case of automobiles, it got taken up automatically—the math of it, you automatically took account for those losses. You didn't have that problem when you were designing a car, but they didn't know how to—they didn't have equations for this weird thing, so they thought they knew what to do, and the equations were wildly optimistic, so people were building things that had more aerodynamic loss than they realized. They thought, well, even if it's worse than that—that was the argument—even if it's worse, you still have this problem when you have the curved solar array, that it's going to be limited by the weakest portion. Being able to overcome that problem.
So it was two elements—realizing the aerodynamic thing, and then with Alan, realizing how you could compensate for the problem associated with a curved solar array. There was one meeting where some GM people were very troubled, and they said, "Ford has been working on this. They've had something for 18 months. There's all these other people doing stuff. No one's doing this. Someone would have surely discovered this by now." And Paul MacCready's answer was, "Well, [laughs] why don't you have Ford build it then?" [laughs]
ZIERLER: [laughs] That's great.
RIPPEL: There were a few seconds of silence, and then we went on from there.
ZIERLER: Now, as a result of Paul's insistence that the solar panels be built into the form of the machine itself, is that the essential challenge that you and Alan had to work on? Would that challenge not have been there if you had the solar arrays as a separate—
RIPPEL: Sure, it would have been a lot easier. Now, that was not Alan's only challenge. Alan also developed the inverter for the motor. The motor was a DC brushless motor developed by the Remy division of General Motors. It kind of highlighted a magnetic material they developed which was fairly low cost, a permanent magnet material called magnequench. A permanent magnet motor is useless without an inverter, just like an induction motor is useless without an inverter. Alan developed the inverter, and there were a lot of decisions to deal with in the design of the inverter. Alan just went ahead and set his own specifications and designed everything. There was a group at General Motors that disagreed with almost everything Alan was doing. One of the smart things Alan did is he set up what the interfaces were—the plug types, the size of everything—and he said, "Why don't you guys develop your own inverter, and you can plug it in, and it will work. As long as we meet these specs." Of course it never happened. It would have taken them a long time to develop any inverter. Alan just went ahead. His approach was make things happen and don't get hung up with all the endless meetings where you don't agree on things. That's his strong point, and also it probably would be a limitation that he faces, working in a group. He has a strong view of what he wants to do, and if everyone else happens to line up with that, fine. But then you don't need them anyway. The bottom line is he works best—
ZIERLER: That's why he's a consultant, not a company man.
RIPPEL: Absolutely. Now, the inverter had—we started out, everything looked fine, and then we had some semiconductor failures. I was involved in that, analyzing that. You never know for sure that you've solved a problem, especially when it's something that happens seldom. The vehicle I think had been tested for a couple hundred hours when they started seeing some of these problems. Then you analyze it, and you hope you've solved them, but you don't know that you've solved them. You won't know until you have more testing. What they did is they made I think five or six copies of the inverter, just in the unlikely event that in the race, the inverter would blow up, to be able to put another one in and continue on. In the race, there were no inverter failures. There were no electronic failures at all, as a matter of fact. The only thing that happened is they had a couple of flat tires, and they expected to have that. So it was a great success. It won the race by a day and a half over the second place vehicle, which was Ford Motor Company. There were 25 vehicles in it, many of them Japanese. At the time, Japan was definitely a leader when it came to doing things in power electronics and solar panels and the like.
ZIERLER: In terms of your own excitement, the things that were really fun for you, given the fact that initially your work with AeroVironment was very part-time, did that speak to you in terms of what you should be doing full time? Was that sort of the transition for you away from JPL toward AeroVironment?
RIPPEL: At the end of the Sunraycer, I had no intention of leaving JPL. Well into the Impact project, I had no intention of leaving JPL. The first inkling of anything was when I was contacted by Hughes. They said, "How would you like to work at Hughes? We'll pay you more than you're getting at JPL." And on and on and on. I didn't want to do that, so I rejected that. Now I'm jumping ahead a little bit; when it came to the possibility that AeroVironment would be intimately involved with General Motors in a production car, what later became the EV1, that's when I decided to work for AeroVironment. Now had I known—here's the interesting thing—had I known that shortly after I joined AeroVironment, General Motors would terminate the relationship with AeroVironment in connection with the EV1, I would not have left JPL. You can see my restlessness, because I was at AeroVironment. I started at AeroVironment in October of 1990. Then I left AeroVironment, and Alan and I formed what became AC Propulsion in February of 1992. Alan left his consultancy well before I left AeroVironment. Alan persuaded me to leave AeroVironment, and I persuaded Alan that we weren't going to work out of his home. We were going to do this right.
ZIERLER: You were going to be a real company. [laughs]
RIPPEL: I was the initial president of AC Propulsion. One of my jobs was to bring in funding, and I wasn't very good at that.
ZIERLER: Let's go back to Sunraycer. First, were you in Australia? Were you on scene?
RIPPEL: No. I was a dad with a two year old daughter at the time. I had the opportunity to go, but I didn't want to go and leave the family.
ZIERLER: As a matter of teamwork, where do we see your DNA specifically in the Sunraycer?
RIPPEL: In the Sunraycer, not a lot. I was involved when there were problems. Alan would call me up almost every night and say, "I'm doing this and this." I'd ask why, and so there were a lot of times I was learning stuff from Alan. I was a good sounding board. Obviously there were times where he did things differently because of discussing things with me. We'd converge on something, and would Alan have done it that way anyway? Maybe. I don't know. But it was his design, and I was a support to him. There was no question about who was doing the design work, the lead design on it.
ZIERLER: Beyond Ford, how good was your intel on the other competitors? Did Sunraycer go to Australia, and everybody was confident that they were going to crush it, they were going to win the race by far?
RIPPEL: I think GM had a little bit of intel on that. I had seen in the general press pictures of the other vehicles, and especially hearing people talk about what they were doing. I had a feeling that we were going to win. The question was how much. I didn't expect to win by a day and a half, but I was pretty sure we'd win. But what was interesting is the learning curve. Two years later, the race was reheld, and GM did not enter, and it was good they didn't enter, because they would have lost. Honda took things over, and the time they had was considerably better than the GM time two years prior.
ZIERLER: It's such an irresistible question—the obvious parallels between the race in 1968 and the race in Australia. Obviously you're at a different stage in life. It's different technology. It's a different continent. You're not on scene in Australia. But what were some of the similarities going through your mind?
RIPPEL: Let me tell you what the similarities are: young people, in both cases. It was one of the things that further reinforced my knowledge that if you want to do something really worthwhile, you need young people. I look to other things—the Apollo program. It was amazing; the average age was in the low thirties, I think. What happens is people accomplish things when they're young, like Einstein did, and then you get to know them when they get old. I think that was one of the things that would be a commonality.
ZIERLER: What's that about? Audaciousness? Energy?
RIPPEL: Yeah, and it may be just the dynamics of the way things work with communication. When Einstein was doing his good work, he was busy doing the good work, and people didn't know about it, and if they did, they wouldn't have valued it as they did later. Later on, Einstein became more available to talk to the press and the public, and the work that he had done was gaining an appreciation. I think there's that dynamic that generally occurs. I think older people should work harder at not just the PR but also doing the engineering or whatever. What happens also is you start out as an engineer and then if you're good, you're moved into management, and you might not be a good manager, so you reach that point where you've reached your level of incompetence.
ZIERLER: What about the applicability question? To go back to 1968, one of the motivations is that at a very early stage, you recognized that electric battery-powered vehicles could be a viable mode of transportation. But with the Sunraycer—
RIPPEL: Excellent point.
ZIERLER: —that was always understood to be a novelty, I assume?
RIPPEL: That's right. It still would be. It's an excellent point. I don't see the possibility of a solar-powered vehicle without a battery in it. The solar panel, if it's cheap enough and whatever, it can augment. If you're driving only 20 miles a day and you park in a parking lot in Phoenix, Arizona, the solar panel gives you a good portion of the energy you need. But if it were just the solar panel without the battery, the vehicle would not have utility. You couldn't drive at night, for example. The realization is that the core technology is that of an electric vehicle, and the solar panel is an add-on. However, you've got to go a step further. Look at today. You have a Tesla vehicle. It doesn't have any solar panel on it, but you've got the solar panels on your roof, and those solar panels are providing more energy than the car uses. The technology, the elements, the components, that were in that race were clearly relevant to all of the things we want in the present world. It was a good idea. Those vehicles could showcase the technology, the individual components.
ZIERLER: Then where is the irony or the historical accident that it was the Sunraycer that prompted GM to do the electric concept car, and not the VW 20 years earlier?
RIPPEL: Right now, David, you are getting to the thing that is closest to my heart. The history books, other things that have been said about this, they give the picture that after the Sunraycer, General Motors came back to AeroVironment, and said, "AeroVironment, can you do something with electric cars? We're interested." That is not at all what happened. It was just the opposite. After the success of the Sunraycer, AeroVironment had a meeting in January, 1988. I was still a consultant to AeroVironment. I was still full-time at JPL. I was at that meeting. Alan was there. Alec Brooks, Paul MacCready, and other people from AeroVironment. The theme was, "Now that the iron is hot, let's strike. Now's the time to put a proposal together, because if we wait, GM may lose interest."
ZIERLER: There's also, what's next on the agenda for AeroVironment?
RIPPEL: Yes, that's right. You keep the ball rolling, keep the money flowing. Paul MacCready started out discussing what he thought made sense, and he felt, in his view, that a bread-and-butter vehicle, a delivery van of some sort, would make sense. A utility vehicle.
ZIERLER: Not a passenger vehicle?
RIPPEL: People knew where I stood. I wanted to see a high-performance passenger vehicle.
ZIERLER: Something fun to drive.
RIPPEL: Something fun to drive. I didn't realize at the time that Alec Brooks was on my side. Part of the reason I didn't realize it is because Alec didn't want to go against his boss and owner. I realized I was on the losing side. Alan was silent. Alan does not remember this meeting. Finally, Alan spoke up and said, "If we're going to do something like a bread and butter vehicle, a delivery van that uses conventional technology, I don't want to be involved." People realized how important Alan was to anything that would happen. If there was going to be something useful, they needed Alan. So the owner of the company, Paul MacCready, switched courses in a couple of minutes.
ZIERLER: That goes to show how reliant Paul was on Alan. He needed Alan on board.
RIPPEL: Yes. He needed Alan. Yes. He knew also that if Alan wasn't in it, my interest might not be in it either.
ZIERLER: Also, what's cool about a delivery van? [laughs]
RIPPEL: I know, exactly. That changed the course of things.
GM and the Great EV Experiment
ZIERLER: What you're emphasizing here, Wally, is that it's AeroVironment going for it and pitching GM, not the other way around.
RIPPEL: That's right. That's really important. It was not just that meeting; it was a very difficult battle that came ahead, the lobbying. Howard Wilson at Hughes lobbied for it. Of course, AeroVironment. A lot of things were attempted. It was a good while before GM signed on to do it. But Alan got started building stuff right away. AeroVironment had a budget set up for him so he could buy components and have a consultant's salary coming from it. It finally did come through, but it was quite a battle to get GM convinced that they should do this. I think in the end, at least for a while, they did regret it. Because once they got on board and this became a real thing—I had a secret meeting, as I mentioned last time, with the CARB and gave them a heads up that an electric vehicle would be developed that would be fun to drive. That at least got the ball rolling a little bit with what became the ZEV mandate. They probably looked further and got other inputs. I'm sure they did. The ZEV mandate then was what held GM's feet to the fire. That [laughs] now you're going to build this. That's where the cost of the Impact was a few million dollars, but the cost of doing the EV1, by the time they were done, with advertising, with all sorts of stuff, was over a billion dollars, and it was at a time when GM was running in the red, so it was a difficult time for them.
ZIERLER: And they were not producing great cars. The 1980s was a low point.
RIPPEL: Oh, it was a lowest point. I'll tell you a story about that. The Impact was unveiled at the 1990 auto show in Los Angeles. I was there, and I went around looking at different vehicles, and especially hung around the GM area, with the Impact, and answered questions and so on, informally. I noticed one of the GM cars had the hood open, the front hood, so you could see the engine. I looked carefully and I saw the strut that held the hood open was the same strut that my father-in-law had on a GM car he has, and that strut failed after 18 months. I talked to the guy with it. It was an Oldsmobile something-or-other. I said, "I notice the gas strut that's used on the front hood is the same as you've had for several years, and it fails after a couple of years, after about 18 months." He said, "Well, we look at that as a replacement part just like windshield wipers." That really bothered me. I said, "You see that vehicle over there?" [laughs] I was really nasty. "You see the Honda Accord? That's the replacement part." [laughs] I didn't engender any friendship in doing that, but it was an attitude they had at the time that was not good. They thought that they had a captive audience, and they didn't appreciate that the Japanese were going to take market share. They used to have guaranteed market share.
ZIERLER: It's an important point, too, because at this point in the late 1980s, early 1990s, the Japanese, their initial toehold in the American market was based on fuel efficiency.
RIPPEL: Right, right.
ZIERLER: But what you're saying is now 15 years later—
RIPPEL: First, fuel efficiency and then quality.
RIPPEL: Quality came. First people thought, "Well, I'll buy this little flimsy car, because at least I can afford the gas." Then they found it wasn't so bad. Then when they got the next one, they thought, "Wow, it's really good!" [laughs]
ZIERLER: Let's go back to the decision-making on leaving JPL. If I understand correctly, it's only with GM's support of what AeroVironment is doing that you joining AeroVironment was a sufficiently stable career move? It was not too risky at that point?
RIPPEL: That's right.
ZIERLER: Because JPL, that's a quasi-federal job. It's a stable position.
RIPPEL: Absolutely. And it was a job that I liked because of the learning environment. It connected with Caltech. My education was continuing on, and I was getting paid to learn. I liked that. But I also had this burning desire to see something happen with a product. That's why I made that move to AeroVironment. But that was after the Impact. That was in the mid 1990s that I considered that. The actual move was in October of 1990.
ZIERLER: As you were thinking about leaving JPL, with some level of frustration, whatever the right word is, what could you point to besides the report that you had built at JPL, that actually moved the mission forward?
RIPPEL: What I had at JPL was I had reports, I had some patents, I had a lot of new technology things. I was identified one year as the second most prolific patentor at JPL, so there was IP and all that. But all that, when I sat down and looked at it, it all amounted to reports, paper, and not real stuff.
ZIERLER: A Sunraycer. Not an EV1.
RIPPEL: Yeah, yeah. Well, and the Sunraycer would not have satisfied me because that was a curiosity. But the EV1, the first production, the first modern electric car, that captured my imagination. That I could be an instrumental part of that and help in the design of that, that I felt was worthwhile.
ZIERLER: Have you kept tabs subsequently on all of the patents and all the reports? Have any of those gone on to a life of their own?
RIPPEL: There was one patent that was interesting, a heat sink patent. Heat sinks are things for like a radiator in a car, for extracting heat from components that produce heat, and radiating outwards so the part doesn't get too hot. There was an invention I had, it's called the split air feed heat sink. It's a very simple idea based on understanding a little bit of the physics of heat transfer. I invented that for the sole purpose of electric vehicles. Now, here's what's so interesting. That was air cooling. We used this technology in the Impact, but I didn't appreciate that when cars would go into real production, air cooling would be out, and so the patent would be useless. I also didn't appreciate that the patent would have value for laptop computers, and without my realizing it, it was used by HP, Lenovo, a number of companies. I never knew it. Finally the patent came to the end of its life. I had gotten, for a few things, a few thousand dollars' worth of royalty, but nothing of any consequence. A company in Texas that deals with intellectual property saw the patent, and they realized that people were violating it, HP and other people. They were able to sue these companies, HP and Lenovo and others, on a retroactive basis. Even though the patent had become obsolete, its time had run out, they were still able to go back and show during the last five years that people were violating the patent. What they did is they purchased the patent from Caltech for one-point-something-million dollars, I forget what. At the time, when I was at JPL, there was an agreement where I'd get 15% of any royalties that came into Caltech. At that time, when all this happened, I was working at the company that I had cofounded with Alan, and a phone call came in that I should check with Caltech; there's a royalty check for me. I thought, "That's nice. It will pay for whatever." I was expecting to see a $1,500 check; it was a check for $105,000 or something.
ZIERLER: Whoa! [laughs]
RIPPEL: [laughs] I made the mistake of depositing it at an ATM machine, and that caused further problems. [laughs]
RIPPEL: I realized Caltech was not aggressive in defending patents. I needed to realize that if something was going to come, it's not like people beat a path to your door, saying, "We're thinking of using your patent." You have to be the watchman, the police officer. They won't do it for you. So there was not any real royalties I got from the patents at JPL, but it's a badge of honor, so to speak, that you thought of some things. Some of the things I thought of were used in spacecraft, so that was nice.
ZIERLER: In terms of the transition and the riskiness, did you take a pay cut? Was this a lateral move?
RIPPEL: When I moved to AeroVironment, it was lateral in a pay sense, and it was a step down, I felt later—and you'll see what happened—it was a step down when GM pulled out and I realized, "Okay, I'm here, and I'm probably not going to be doing what I thought I would be doing." Alan quickly got discouraged with AeroVironment and terminated his consultancy in I think late 1991, October of 1991 or something like that. He wanted me to join with him to start an electric vehicle company. I resisted that at first, and then I thought, "I'm not going to be that happy doing nonelectric vehicle things here at AeroVironment." So I left AeroVironment in early 1992 and with Alan, we formed AC Propulsion. That was difficult for me financially, because I thought I had some things lined up with investment, and it didn't work out. I wasn't able to bring in any investment.
ZIERLER: You were really only at AeroVironment for like a year and a half?
RIPPEL: The first time. [laughs]
ZIERLER: Right, the first time. Where was GM during that time period?
RIPPEL: There was a contract between AeroVironment and GM, but it was almost exclusively dealing with hybrid vehicles. Electric vehicles were not part of it.
ZIERLER: The concept car is not yet viable?
RIPPEL: The work had been completed in 1990. January of 1990 was the auto show, so the Impact work had all been completed. The stuff in the Impact was what they used to get started on the EV1. They had several attempts. You look at when the EV1 finally came out, that was 1996. Between 1990 and 1996, six years of development, there were I'm told a couple of false starts. I don't know the details, because it was kept within the GM family what was going on. I had almost no contact with the EV1 effort. I had a little contact when I was first at AeroVironment. They wanted to utilize the dynamometer facility that I had put together at AeroVironment, for testing motors that they would be building. This was in the very early days when they were just getting started with this. That surprised me that they wanted to use our facilities, because the Delco division built electric machines. Earlier, they were building stuff for diesel electric locomotives, the Electromotive division at GM, so I was surprised that they wanted to work with AeroVironment where we would be doing testing.
We got a motor from GM, and before I put it on the dynamometer, I did some preliminary tests. I connected it to 60-hertz power, and it should have run at 1,800 RPM. It didn't work at all. It didn't even turn. I analyzed it further and I realized the motor was completely mis-wound. We sent it back and I told Alec, "I know the next motor we get will be perfect. There were some mistakes made, and I'm sure they're embarrassed, and that's not going to happen again." I said, "Mark my words, we'll get a motor back in less than two weeks." Well, months went by, and finally we got a motor. I performed the same test, and it ran faster than 1,800 RPM, which, if it was wound correctly, would be impossible. I analyzed that and saw that there were—figured out kind of what the defects were in it. Finally, the third time around, they wound it correctly. A little after that, one of the GM managers visited us at AeroVironment. He said, "This is expensive work that we're doing." He said, "We've spent half a million dollars just trying to get this motor thing."
ZIERLER: What does it mean to wind a motor correctly?
RIPPEL: An induction motor or any motor, if you look at the stator, there are these slots in what looks like an annular structure made up of laminations. You start out with coils of wire that are put in those slots, and those coils of wire get connected together and so on, and that overall connection of those coils is referred to as the winding, or the motor winding. There's a lot of different ways you can wind a motor. You can create different numbers of poles so that when you plug it into 60 hertz power, it will run at either 3,600 RPM, 1,800 RPM, 900, some factor of 3,600 divided by N, where N is the number of pole pairs. That's technology that went back to the early 1900s. Now of course what we're doing is different because the motor is paired with an inverter. This was one glimpse I got, is that they were off to a difficult start. My feeling is if you're having problems with this, you're going to have a lot of problems with an inverter. The inverter was farmed out to the Hughes division. Hughes was fairly literate in electronics. They did a reasonable job. There was a lot of things they had to learn. They had a challenge taking what Alan had done, even though it was semi well-documented, and translating it into things they understood and that they could use. There was a difficult transition period. Tesla would experience the same thing. Alan communicates efficiently but not always completely. It was a difficult thing for people, and it would be probably difficult under any circumstance, where you've got new ideas. Unless it's very well documented, it becomes difficult.
ZIERLER: Just to zoom out for a second here, so the chronology of time, that short period of time when you're at AeroVironment for the first time, this is flush off of the success of the Impact concept?
RIPPEL: Yes, yes.
ZIERLER: And you were really not involved in any of that, but you saw that—
RIPPEL: No, I was intimately involved with the Impact design. The Sunraycer, I was not involved so much, but with the Impact, I was. I'll tell you some of the things where I was involved.
ZIERLER: While you were at JPL, as a consultant?
RIPPEL: As a consultant.
ZIERLER: We have to develop that more, then.
RIPPEL: Heat transfer, heat sinks, I was involved in. I was involved with the concept which we had in the Impact but it was not carried forward, of integrated recharge, where the inverter was used not only as the inverter to provide the motor function but also as a charger. Some of that, the car companies will probably discover in the future, and things will be done with that in the future, but right now, chargers are built as a separate thing, and it adds to the cost of the vehicle. The chargers are not rated at as high a power as the charger in the Impact. That was my contribution. I did a lot working with Alan on the inverter. The fundamental control ideas of how the induction motor would be controlled were ideas that I had developed at JPL, and those were carried forward. They were done non-digitally at the time, with quasi digital analog mixed circuitry of digital and analog. That technology later at Tesla would all become pure digital. So yeah, I had a significant role in what was in the Impact. The Impact, in turn, was carried forward to the drive systems that were used in the EV1.
One little curious thing that I contributed in the EV1, and it was not the usual thing you'd think of as engineering, was motor sound. I knew how to design an electric motor that would be silent. Tesla has designed motors that way. The motor in the EV1 was deliberately designed to have some acoustic sound, and people loved it. It had the sound of a—people described it as a jet engine—when you'd accelerate. You'd hear the turbine sound. The pitch would increase in frequency as the vehicle gained in speed. When you would apply full power with the accelerator, the intensity of the sound was greater. It really captivated, I think, a lot of people that had the EV1, and they liked that. It's something that I think Tesla and other car companies should think about, especially when you do performance vehicles like Tesla. Silence is not a good thing. At full power, you want the motor to speak to you, and you want to hear that something is happening.
ZIERLER: It's that connection with the driver.
RIPPEL: I knew how to do that, in the design. That was simply copied in the EV1. I don't think they knew—they thought it was designed that way for efficiency, and it wasn't. It was designed—certain things were done for the acoustics.
ZIERLER: To return to this theme of applicability versus novelty, your involvement on the Impact, obviously it was a concept. Did you see it, at the time, that it was a concept on the road toward mass production and mass adoption for consumers?
RIPPEL: I surely hoped so. The Impact, I felt, definitely was good enough to be parlayed into a production vehicle. The issues were not fundamental design changes. The issues were making things so that you can produce them on a production line. The way you do fasteners and things like that is different. Molding, using cast aluminum in place of other things, that we were doing, that's in fact what GM did. When you look at the EV1, it was designed as a real automotive product. A lot has happened since then, of course, in the way things have been refined. But the use of castings in place of sheet metal structures, it was built—the electronics, for example, looked automotive already in the EV1, whereas everything that I had been familiar with and had been doing was industrial or prototype. I wasn't making castings and things like that. You wouldn't do that, because it's too expensive for a prototype. Now actually people are doing castings, because of the numerical machining being so cost-effective. You start out with a big block of aluminum that weighs a couple of hundred pounds, and it gets whittled down to where it weighs eight pounds or something, with lots of chips. The chips are reused, and you have this complex structure that has been carved out of a solid piece of aluminum. The next step, of course, is you make the molds and you make the same thing, where it's being molded. It's a new way of producing things that at the time was not being done.
ZIERLER: Given the success of the Impact and the challenges that the EV1 would have, just a counterfactual kind of question—if you can mass produce the Impact in a vacuum, where you didn't have to worry about the challenges of scaling up and what you needed to change as a result, and you were just able to cookie-cutter the Impact, exactly what it is, not for one car but mass produce it, would the Impact have had the same problems or the same challenges that the EV1 had?
RIPPEL: Oh, that's a good question. As I said, the Impact was not designed with castings and things that were suitable for a production line. The other dimension is that the original Impact was lead acid, because that's all we had, and lead acid at best was marginal. Now, my calculations had shown that we could have a 100-mile range. We fell short with the Impact, and then things progressively have gotten worse. As we have these super batteries, the lithium ion battery, people have at times gotten a little bit sloppy in the way we design the rest of the vehicle. It has reverted back more to the way people do things in the internal combustion world. When you have a limited supply of energy, you're more careful. We saw this with computers. The early people who had designed code were very careful in the way they used memory. You had code writing that was efficient for the use of memory. Then you came along with super memory, and an extra gigabit of memory means nothing, so you don't write code that way now. It's written in a different way, and it's more efficient for people to be sloppy in terms of the memory use. In some ways, it's a lot easier, because you look at code and you can understand it easier, where you're less efficient with the memory use. This has been something that has frustrated Alan. Alan is aware that we could do much better in energy utilization. The efficiency could be better. We have kind of drifted into this area where we're less efficient than we could be.
ZIERLER: The electric Hummer, right? That's the apotheosis of this.
RIPPEL: Yes, sure. Obviously you're not trying to minimize the number of kilowatt hours per day or per year or whatever, but I think there's still some good work that can be done in gaining efficiency. Learning how to make better gears, for example. You think of gears as old technology, but the gears are very important, because as you go to a better quality gear, you can go to a higher-speed motor. As you go to a higher-speed motor, you can actually gain efficiency and also reduce the weight. You can reduce the cost in many cases. An old technology can dictate what you can do with the new technologies. They're coupled.
ZIERLER: For that short time you were at AeroVironment initially, what was the mandate? Coming off of the Impact concept, was the EV1 already on the horizon? Was that the main thing to do?
RIPPEL: Of course I left JPL to join AeroVironment because I saw the EV1 coming about, that that was going to occur. The mandate was in place pretty early, in 1990. With the mandate in place, we knew that there were going to be cars produced. The mandate initially called for 2% of the cars being zero-emission. It didn't use the word electric, but it was understood that the only option you had really was electric.
ZIERLER: This is coming from California?
RIPPEL: California, right. But we also knew that if this was successful here, it would spread to other parts of the countries.
ZIERLER: California is the beta tester for the United States.
RIPPEL: Yeah. The goal was that by the year 2000, it would be up to 10%, and we're still not there. You could say California has a successful electric vehicle industry with Tesla, but with all of that, we're not at 10% sales yet. And 10% sales means you only have a few percent, then, cars on the road that are electric, so we've got a long ways to go before electric cars start to really help and put a dent in the carbon emissions.
The Origins of AC Propulsion
ZIERLER: For that brief time, what ultimately convinced you that you should go off with Alan and do your own venture?
RIPPEL: [laughs] Alan.
ZIERLER: You would have stayed put?
RIPPEL: I think I would have stayed put. Alan gave me the courage to think that I could raise money. I had never done that before. I took the step. That was a bigger step than leaving JPL. That was a step into the unknown, really. For the better part of a year, I was without any income. Originally, we started where the company would be 50/50, Alan and me. But Alan was putting money into the company, and we had a formula, so he was gaining equity in the company, while it was being diminished for me. It finally got to the point where I realized I had to leave AC Propulsion to survive financially. And guess where I wanted to go? Back to JPL. You'd have guessed that. I contacted people at JPL, and they were enthused about my coming back. But the person who—I won't mention his name—the person who headed up the battery group at that point, at first he seemed very enthusiastic, and then something happened, and I have no idea what it was. He said, "You need to come back as a consultant, a no-fee consultant, and bring some funds into JPL." I should have realized, "Well, if I can't bring it into AC Propulsion, why would I be successful at JPL?" I was working for more than a month, a month and a half, as a no-fee consultant, and I realized, "I really do need income." I had to borrow some money at that point. So I went back to AeroVironment. There was a project—ironically, it became a NASA project—for the Helios airplane, which set a record, an altitude record. The goal was to parlay that into an atmospheric satellite, where the airplane would be able to, with solar energy, stay aloft indefinitely. The energy would be captured in batteries, and stored for overnight, so that the plane could fly 24 hours a day and would be used for telecom type—like where you send internet messages from tower to tower, or something like that. There was a lot of potential use for it, if it could be made to work.
What happened there was interesting. The Helios part was a success. We got to almost 100,000 feet. 96,500 feet. We set a bunch of altitude records and other records. It was generally viewed as a success. I developed the motors for the plane, the electric motors, and some of the other power electronics for the plane. In a sense, I felt I had accomplished something. Yet, it was irrelevant to the field of electric vehicles. I felt I was kind of off from where I wanted to be. I enjoyed working at AeroVironment. I enjoyed the environment there. I enjoyed working with Alec Brooks. Then Alec left for a while, left AeroVironment, to join AC Propulsion. That's interesting. His goal was to parlay the tzero into a real product, to do what ultimately Tesla did with the Roadster. The problems there were Alan and Alec working together, I think. Probably some of it also is that we were more engineers than businessmen, so there's that side, too.
ZIERLER: How long were you at AC Propulsion initially?
RIPPEL: I was a cofounder of the company. I was there at its birth, which was in February of 1992. I left at the end of November of 1992.
ZIERLER: That's a short stint.
RIPPEL: Yeah, it is.
ZIERLER: Was there a share in the company that you sold, or bought out of? How did that work?
RIPPEL: Yes. Well, it was more complicated than that. When I left, it had been whittled down. I had 10% of the company. Then AeroVironment was involved with General Motors, and General Motors said, "If Wally is going to join AeroVironment, he has to relinquish any interest he has in AC Propulsion." That was a condition of my coming back.
ZIERLER: Because they saw AC Propulsion at this point as a direct competitor?
RIPPEL: That's right, yeah. A threat. So I had to do that.
ZIERLER: What did AC Propulsion have to its name at this point? Was the CRX even retrofitted yet?
RIPPEL: Yes. When I left, they were selling drive systems. We sold our first drive system to Honda. It's a little side story that's interesting, because it gives a window on Alan, I think, and maybe on me, a little bit. I don't know. The first drive system was sold to Honda, and the way we got it to them, they wanted it fast. I think their American corporate thing was in El Segundo or something. What Alan did, to save time, is we drove the CRX down to El Segundo, and we had a separate motor with us and separate inverter. They wanted the motor tested for some miles, and that was the test, the burn-in test. The motor was hot when we took it out of the car and put it into the crating that they already had designed, with 25 miles of driving on it, and we put in the new motor and the new inverter so we could drive home. They then got the motor, and the technician testing it made a math error, and they concluded that the power was too low to be usable in a vehicle. There was just a math error. Alan quickly caught on what the error was. We saw a report on it, and Alan figured it out before I did, of what the error was. Alan said, "Look, I'll write a letter explaining what the error was." I said, "Alan, be careful. This is Japanese culture we're dealing with here. Somebody is going to see that they made a mistake, and it's going to be bad." I said, "What we should do is send them a suggested way of testing it. Go through a worked example. Have them send the system back to us .We'll dust it off. We'll check the calibrations. And it'll avoid someone taking the fall for screwing up."
ZIERLER: Losing face.
RIPPEL: Yes. But Alan prevailed. And that was the last contact we had with Honda.
ZIERLER: Oh, wow.
RIPPEL: It's what I expected. It could have been something else that caused it to fail, but I'm pretty sure that the termination was because of some bad feelings. Alan was very bold and direct. If someone made a mistake, he'd say, "You did this wrong." He would expect the same with himself. If you caught a mistake that Alan made and you said, "Alan, what you did was wrong," he liked that. Unless, of course, you were wrong yourself. Then he'd fight back. But he's very pragmatic. In some ways, I wish people could be that way. It would be nice. [laughs] If politicians would say, during a debate, "You're right. I was wrong on this." [laughs] It would be a different world.
ZIERLER: Last question for today. When you went back to JPL initially as a no-fee consultant, were you hoping that that would just be your long-term home once again?
RIPPEL: Yes. Well, and it was worse than that. I've got to tell you that the story is not over. I went back to AeroVironment. I had left some things at JPL. I contacted this person who was heading up the battery section. I said, "I left some things. I'd like to pick it up." He said, "Wally, I put out a memo describing how you embarrassed the laboratory, and people have read that." I said, "Tell me about it." He said, "I'm not going to." It was the strangest thing. I talked to other people. Had they seen the memo? No. I talked to the head of JPL. He said, "Any memo will be collected, and you don't have to worry about it."
ZIERLER: This is Ed Stone at the time?
RIPPEL: Yes, Ed Stone. This person, other people had had problems with him, and he may have felt that I would be a threat. I don't know what. But he clearly didn't want me coming back to JPL and other people did. It was a sad final connection I had with JPL. It shouldn't have been that way. No one knew of what he was talking about. I know Rao Surampudi at JPL, and Rao knows this person. No one knew what he was talking about with this memo. Was it real, a threat, or what? I don't know.
ZIERLER: In terms of the grand sweep of history, your interest in electric vehicles, would you have been able to continue on that track at JPL?
RIPPEL: When I was going back, and at the end of 1992 wanting to go back, I wanted to [laughs] really get serious about batteries. That's why it was the battery section and not some other section at JPL. I started to see, "We need to work on this, and stop kicking the can down the street." As you've heard in my interview, you can see what I did. There's a pattern here. When I was at Caltech, I converted a vehicle. I did the things that I could do. I realized the battery was a problem and I wanted someone else to do that work. Then at Cornell University, I didn't fight as much as I should have, with an advisor, to do the work. I was invited to come back to Caltech. I didn't grab things and fight. I had a number of opportunities to work in the battery area, and I probably—it was a thing of lacking self-confidence, so I did what I knew I could do. I kind of regret that.
ZIERLER: We'll go back to the history class and the pronouns—they, we, and I.
ZIERLER: On that point, we'll pick up in 1992 for next time.
RIPPEL: Okay, great.
[End of Recording]
ZIERLER: This is David Zierler, Director of the Caltech Heritage Project. It is Monday, January 3rd, 2022. I am delighted to be back with Wally Rippel. Wally, it's great to be with you, and Happy New Year.
RIPPEL: Thank you, and Happy New Year to you. Hopefully, we'll have a better year in terms of COVID and some other things.
ZIERLER: Amen to that! We left off in our last discussion talking about the circumstances of you leaving JPL. Just as a way to set the stage for AC Propulsion and to get an understanding of the sequencing of events, were you talking to people like Alan Cocconi even while you were at JPL? Were you thinking about an endgame that might lead you to this next venture in electric vehicles?
RIPPEL: That's interesting. I have memories, thinking back. I was at JPL, as you know, working as a consultant in connection with AeroVironment. I had no intention of leaving JPL. I got a call from Hughes Research. They were going to be doing the power electronics for an electric vehicle for General Motors and they wanted me to join them. And I did not. I talked with them a little bit, but it ended pretty abruptly. So I was not thinking about leaving for AeroVironment or anyplace until it looked like AeroVironment would be intimately involved with General Motors in the design of what would come after the Impact, in other words the EV1. It was on that basis that I left JPL and joined AeroVironment in October of 1990. That's when I actually left. It was maybe a month or so before that, that the plan was put in place. The EV1 was the thing or—it wasn't called the EV1 yet—but the idea of General Motors building an electric car that would be in mass production, and where AeroVironment would be providing some support, consulting or otherwise. It was on that basis that I left JPL.
ZIERLER: Tell me about the earliest discussions between you and Alan and anybody else I might know about, that actually led to the formal creation of AC Propulsion.
RIPPEL: As you know, there were some intermediate events. I was at AeroVironment starting in 1990. Shortly after I was there, I was aware that things changed, that General Motors would have a contract with AeroVironment dealing with hybrid vehicles but not with electric vehicles. They would be developing an electric vehicle on their own, but they decided that the wisest thing for them would be to not have any connections with the outside world when they did that. That was kind of a surprise to me. I realized I had made this step from JPL to AeroVironment based on what I thought would be a new step in my career, and that was changing. That was a negative. Alan had been involved with AeroVironment as a consultant. In I guess early 1991, he left AeroVironment, feeling, as I can understand, that there was not a future with electric vehicles there, that the decision General Motors made would make it impossible for him to do anything of any consequence at AeroVironment. That was the first thing, and I was aware of his unhappiness with AeroVironment as well as General Motors. Alan started talking about—it was Alan's initiative—started talking about forming a company. I resisted that. I guess, having moved from JPL to AeroVironment, I wasn't in a hurry to make another move. But Alan kept after me, and I decided, "If you're going to do this, why not do it right?" Alan wanted to work out of his home. "Let's get a facility. Let's get investment." Alan was okay with that. The understanding is that I would be the president of AC Propulsion, which I was. I was the first president of AC Propulsion. In February of 1992, I left AeroVironment and AC Propulsion was incorporated that month. We got a facility in San Dimas, and that was the birth of AC Propulsion.
ZIERLER: Was Alec Brooks part of these discussions at that point?
RIPPEL: No, he was not. That's an interesting question. He was not, at least not that I know of. I was in communication with Alan. Alan very much felt that the only way anything was going to happen with electric vehicles is if we made this move, and that if the move weren't made, likely nothing would happen. He was the persuader for me to leave, and I think I was the persuader of how to do things, in terms of trying to have a little bit more of a formal corporate structure. It's interesting to look at what our motives were. I think Alan and I both wanted to see the birth of an electric vehicle industry. This was a point in time where I was just starting to see climate change as maybe a more important issue than conventional smog. There was an evolution of thinking that was taking place. It's interesting, because as you know, I got started thinking about Los Angeles and smog. Then in the 1970s, the thinking kind of broadened to the issue of oil depletion and oil shortage. Then you go all the way up to the 1990s; the thinking kind of started moving then more to climate change.
ZIERLER: Earth Day started in 1992, not coincidentally.
RIPPEL: Interesting, yes. I thought the first Earth Day was earlier. You said 1992? I'm not sure.
ZIERLER: Yeah, that's in Rio, in 1992.
RIPPEL: I need to review my history! [laughs]
ZIERLER: How much of a personal risk was this for you? As difficult as it was to leave JPL and go to AeroVironment, to start a brand new company from scratch, how much personal financial risk were you taking on at this point?
RIPPEL: Well, a great deal. It was a risk because I was moving into waters that I wasn't familiar with. My training was in physics. To some extent I was an imposter in engineering, because I was working in things where I hadn't been trained fully. But then going into the idea of business and raising capital, I didn't know what I was doing, and I knew I didn't know what I was doing. I was willing to do that, because I felt that the value, if it succeeded, would be significant. It hurt me personally a lot, financially. It was a difficult move, at the end of 1992. I had to borrow money from my family to survive. My wife was of course concerned about whether we would be able to pay the mortgage and things like that. Yeah, it was difficult. I moved from the most comfortable environment, JPL, which was also a great environment in terms of education and intellectual. The environment at AeroVironment was in some ways stronger in the engineering than JPL, the reason being that JPL was not focused on electric vehicles. That was a peripheral thing. Yet there would have been reasonably good security at AeroVironment. Then starting this proved to be difficult, and it was a hard time for me personally.
ZIERLER: What reaction did this move elicit from AeroVironment, when you and Alan started to make noise that you were going to leave? Did that refocus their intentions about how serious they should be in producing electric vehicles?
RIPPEL: I'm not sure. AeroVironment I guess felt the confidence that they were doing something, because they had a contract with General Motors in connection with hybrid vehicles. But none of that would be leading to production. That would be something that was ongoing but there was no clear production intent with any of that.
ZIERLER: Take me there on day one. What does that look like? You have the facility. How do you gear up? How do you get operations rolling?
RIPPEL: Well, I don't know that I can answer that now [laughs] because I didn't answer it well then. Before leaving AeroVironment, I thought I had some investors lined up, so that was what I was first doing, was getting those contacts reestablished and firmed up, or so I thought. All of them fell through. I was off to a bad start. Meanwhile, Alan was doing engineering at full speed, and with the idea that this is how we're going to bring income in, so the faster we get stuff built, we can start selling stuff, the sooner we'll have income. Alan was paying the bills basically for AC Propulsion. The rent and buying components and all of that, he was doing that out of his savings. We had a formula, so as he was doing that, my equity in the company was diminishing. We started out 50/50, and each week or each month, it was a little bit less. That was of course fair, and I wish that I had been in a position where I could have been contributing. But I was working at AC Propulsion with zero salary, and with zero contribution on the other hand. Alan was working with zero salary and was putting money into the company.
ZIERLER: Was Paul Carosa there at the beginning, or he came later?
RIPPEL: Paul came later. I started AC Propulsion, as I mentioned, in February. I didn't see Paul until either October or November. He's listed as a founder of the company, but he was not there at the outset nor was he involved with the incorporation. Here's an interesting story, one of these little side stories. Alan has an incredible memory for things that he feels important. You can talk to him and he'll know all the stats on a particular component. Amazing. On the other hand, Alan forgot our incorporation. We worked with someone that I knew from church, who was also an employee at JPL. He helped us go through the mechanics of getting incorporated. We had about two or three meetings with him. Alan doesn't remember any of that. So it's interesting; Alan does not remember how AC Propulsion [laughs] became incorporated! I picked the name "AC Propulsion" and of course you know that I was doing two things, "AC" for alternating current because of the type of drive system, and it's also Alan's initials, Alan Cocconi. Alan was busy working. I said, "Alan, what do you think about the name AC Propulsion our AC Electric?" He said, "Oh, AC Propulsion would be fine." That was the end of the conversation. He was busy. Things like what the company name would be—"Yeah, pick something out." Two minutes is already two much time for Alan. He's a little different type of person to work with, and yet extremely strong in terms of being able to get things done quickly and efficiently, and very high quality. So, a different type of person.
ZIERLER: Was the idea from the beginning to make a Roadster-type vehicle? Was that the only product that was on the agenda from day one?
RIPPEL: Not at all. That came quite a bit later, and that came after I had left the company. The belief was that if we built the key drive components, then the car companies would see what can be done and would carry it forward from there. Keep in mind, what we were building was both the motor and the inverter. A drive system is more than that. It also includes—oh, we also had the integrated recharge. It was the integrated recharge, the inverter, and the motor. But it did not include the gear reduction. With a high-speed motor, coupling to a gear box is not trivial, so we did not have a complete drive system. Later, on review, I realized that that would have been a very important thing, to get the resources together so we could have done a complete package. It would be like buying a computer in the old days, and you get the computer, but you don't have a screen, and you don't have a printer. Those things have yet to be worked out, really. That was a mistake I think we made, thinking that just the motor and the integrated inverter would be enough to get the car companies rolling. There was some interest. We sold our first drive system, as I mentioned, to Honda. But the interest was sporadic, and it was not something that would keep the pipeline full.
ZIERLER: What would that look like, when you sold a drivetrain system to Honda? They would put it in one of those existing vehicles and that would simply be an electric car?
RIPPEL: Possibly, or possibly they'd just use it in the laboratory to test on the dynamometer, to see what the capabilities were, and to use that to make decisions. It's interesting—if you look forward in time, AC Propulsion in 2008 worked with BMW. BMW got interested in electric vehicles and we sold them a drive system which they evaluated, and then they bought like 100 drive systems for it from us to put in 100 Minis, which were leased, I think $850 a month, to people who would be willing to pay that. The purpose of that was to give them an understanding of what can be done with electric vehicles, what are the problems, what are the design issues, and so on. Our idea did work to some extent, but the market size for selling drive systems to car companies to evaluate is a small thing, and eventually that pipeline gets filled up and you don't continue selling stuff. They go off on their own, or the other side is they decide they don't want to go off on their own. Either way, it's not a sustainable business.
ZIERLER: As a business strategy, why not start from the beginning, with building an entire car from the ground up?
RIPPEL: This is interesting. That became an issue with AC Propulsion somewhat later, after I had left. That was the idea with the tzero. The realization, of course, is that if you're going to do that, you have to have access to a lot of capital, something on the order of a billion dollars. When you do vehicles in small numbers, you don't have to go through all the FMVSS crash testing and everything. If you're going to build vehicles that are going to be on the road, there is a lot of upfront investment that is required. That's something that Alan definitely did not feel comfortable with. I have talked to him about that over the years. He did not feel comfortable with that. I had none of the background necessary to bring that type of resource in. That's why you see someone like Elon Musk. He was able to do that. Now, arguably he was not trained as a businessman either. I know he did have times of great difficulty at the outset. But it was a necessary step, and we were not willing to take that.
ZIERLER: If you need that kind of capital, then, how is it that the tzero was produced at all?
RIPPEL: There were only a few of them built. They were built, again, with the idea that this would get interest in maybe the drive system sales. It would showcase the drive system. The idea was that AC Propulsion would eventually be selling drive systems maybe in moderate numbers to the car companies. It did not succeed with the conventional car companies. The tzero was out there for General Motors and Ford and all the other car companies to look at. They weren't interested. It was these individuals, Martin Eberhard and Elon Musk, that liked the idea personally of having a Roadster type car, and when they couldn't get it, they became intrigued with the idea of building a company to build them. Originally, at least one of the versions is that there were going to be two efforts, one with Elon Musk, and one with Martin Eberhard. It was Tom Gage, who was then the president of AC Propulsion, who encouraged these two groups to work together and form one company. Which is what happened, and then finally Martin Eberhard was kicked out of the company.
ZIERLER: What was the timing? AC Propulsion starts in 1992. The first venture is drive systems. How long until we get to the tzero, even if only a few are envisioned to be made?
RIPPEL: I think Alan's vision for the tzero started in the late 1990s when he was aware that GM would probably be backing away from the EV1. The tzero was viewed by the Tesla people in 2004, and the idea for the tzero I think was in 1998 or 1999, something like that. The body already existed. Alan was able to identify a car kit company that provided the body components. He made modifications to both the body and suspension. But the idea of this I think more than anything was as a showcase rather than as a product. Now, Alec Brooks in the later 1990s, in the mid 1990s or whatever, left AeroVironment for the better part of a year, to join AC Propulsion, with the intent of getting the tzero into actual production. Alec had that vision, but it wasn't backed up fully by Alan, so the effort was a frustrated effort, and Alec ended up returning back to AeroVironment, as did I. [laughs]
ZIERLER: What year did you return to AeroVironment?
RIPPEL: With Alan, I started AC Propulsion in February of 1992, and by October, I knew I was in financial trouble. My first attempt was to get back to JPL and work in batteries. That was my plan A. It looked like there was a lot of enthusiasm at JPL for my coming back, but there was one person who did not want me coming back, and as a result, I did not come back. I was there for a better part of a month working as a, quote "no-fee consultant" with the intent that I would bring in funds to JPL. I knew that was an uphill battle. I had failed with AC Propulsion, and I failed to do that for JPL. I left that consultancy, the no-fee consultancy, and returned to AeroVironment.
ZIERLER: What year was that?
RIPPEL: That was the end of 1992. That was in November of 1992.
ZIERLER: So it's really quite a short stint for you at AC Propulsion?
RIPPEL: Yes, it was. I kept in pretty close contact with Alan, the years following, but it was a short time, and it was a tough time for me financially. I've often wondered what would have happened had things worked out, had there been enough investment that I would have not left AC Propulsion. I've asked the question, would I have handled things differently than Tom Gage did in connection with Elon Musk and Martin Eberhart? I've tried to answer that question honestly, and I think that I have one gauge that allows me to give an honest answer. You remember at the start I mentioned with the Impact, we had this meeting at AeroVironment in 1988 to discuss what next. The leadership of AeroVironment wanted to do a bread-and-butter vehicle, and Alan and I held out for a passenger vehicle with high performance. Now, here's the irony. After I left AC Propulsion and Tom Gage became president, their focus became the development of the so-called eBox, which was a converted Scion vehicle. They would sell, at best, a few of them to electric utilities for meter readers and things like that, but it was not like an electric car company, not like a General Motors or a Ford putting something in real production. I think I would have opposed that approach, because I had in the past. I would have wanted to see the high-performance electric vehicle if we were going to do any product. I would have encouraged Alan to stick with that. I think Alan kind of went along with Tom Gage's view of the eBox because Tom made a case that it was the best way of getting short-term funds coming into the company. Of course there would be the argument that I had failed in doing that, so why would I think I could do it? But if I had not failed, if I had been successful getting early funds coming in, I would have obviously wanted to do things differently than Tom Gage. It's interesting to look back and ask how things could have been different. I'm of course very thankful for what did happen, because it led to the birth of the electric vehicle industry.
ZIERLER: Perhaps another way of looking at this is simply, if you had been more financially secure and the question was only how much you believed in AC Propulsion, would you have stayed on those terms?
RIPPEL: Absolutely, sure. As it was, I stayed until I was having to borrow money to pay a mortgage and stuff like that. If I had been in a better position, I would have definitely stayed. I'm aware that sometimes you have to go through a long trial period before you can start seeing net income. It takes a while. I think the lesson that I learned is that engineers do not necessarily communicate well to potential investors, and answering the engineering questions well does not satisfy someone who is looking also for seeing a good business plan. We had a business plan, and it's something that I had put together. I think, but I'm not sure, I think that Alan read the document quickly and, "Yeah, that's okay, I've got other work to do." [laughs] That kind of thing. Alan was not engaged in the details of the business side. He wanted to do the engineering. I think that was his main motive. He may tell people that his motive was climate change; I think more his motive was the challenge of doing the engineering, and doing something that he could do and others couldn't. I think that was his main motivator.
ZIERLER: When you returned to AeroVironment, did your work change from when you had left?
RIPPEL: Yes. We got involved in a program, the Pathfinder and Helios, and I ended up designing the motors for a solar-powered airplane. The goal of the Helios ultimately was that it would be an eternal-flight airplane, where it would have energy storage and solar panels, and it would be able to loiter at 60,000 feet for months at a time, at night operating off of stored energy, and it would be used for certain types of internet communications and maybe for some science applications as well. The plane was developed, and it was under NASA, and was successful. We set some important records, including an altitude record for a propeller-driven airplane of almost 100,000 feet—96,800-and-some feet. It was fun, in a way, working on that, DC brushless motors with integrated inverters that I had designed. But on the other hand, it had no bearing for electric vehicles and the lessons learned in that were not all that relevant to anything with electric vehicles. During that time, I was not really contributing that much to the field, to the art of electric vehicles, not in batteries, and not in even the power electronics area.
ZIERLER: What lessons might you have appreciated about AeroVironment's viability when you came back, given that it also had very uneven or unsure origins?
RIPPEL: That's interesting. AeroVironment was founded by Paul MacCready who is both a scientist and an engineer. He became a businessman again only because it was necessary, but not because that was his primary interest. It was pretty far down on the list. Under Paul MacCready's leadership, the company was marginally profitable. It was just on the edge of surviving at times. Later, the company was taken over—Paul MacCready transferred the company to another person who led it in a much more profitable way. The company went public and it was very profitable then to Paul MacCready and to his family. But the lesson I learned is that you do need some business skills. You think of, for example, someone like Thomas Edison, who you think of as being a great inventor. I don't think he would have been perceived as such a great inventor had he not had the business skills. Some of it was he was maybe ruthless, but he was able to accomplish the business skills that other engineers might not have been able to. There's a lesson from that, and that is, people who are in engineering that contemplate going into business, if they don't have the innate skills like an Elon Musk, they should get training or something, so that they can fulfill that role, because I think it takes more than just common sense. Some people say business is just common sense, but I think that there's more to it than that.
ZIERLER: How long did you work on those initial projects, when you returned to AeroVironment?
RIPPEL: Oh, those things carried me all the way through, starting from 1992 until when I left in 2006. I had worked on a number of projects. There were some sporadic things as I mentioned earlier that were connected with electric vehicles initially when I was at AeroVironment. I did some things with electric motor testing, but nothing of any consequence. The main thing that I did at AeroVironment was to develop an inverter that would be used in electric vehicles, a new type of packaging, and patents were filed for that. Curiously, it's something that Tesla took over. They may be [laughs] violating some of the patents that AeroVironment has. I don't know. At any rate, yeah, I did some work at AeroVironment that did have application to electric vehicles, but a high percentage of what I did was outside of the electric vehicle area.
ZIERLER: Was AeroVironment becoming increasingly more dependent on military contracts in the 1990s?
RIPPEL: Yes. Now, AeroVironment had a couple of divisions. They had a group out in Simi Valley that was doing UAVs, what we now call drones. They pioneered some of this technology and it was used for the military, and they got some good military contracts. That became the basis or a major part of the basis by which the company went public, so the military component became an important one. It's something, as you know, that was very much opposed by Alan. Alan is anti-military from the point that he sees anything with the military leading to weapons that kill people and do destruction. I don't quite have his perspective but I sure respect his point of view. I'm probably on a log scale midway between Alan and the rest of the world. [laughs]
ZIERLER: Were you following AC Propulsion's developments in the late 1990s? Were you paying attention to some of their advances?
RIPPEL: Alan and I would talk a couple of times a week on the phone. When Alan was thinking about the tzero, he was talking about that, and there were a lot of discussions we had. In many cases I was, I think, a good sounding board. I'm not sure that there were any major decisions that I would have changed that Alan made, but it was continued communication that we had.
ZIERLER: Did you ever think about jumping ship once again, once AC Propulsion seemed to be on to something by the late 1990s?
Who Killed the Electric Car?
RIPPEL: No. At that point, I did not. [laughs] I had gone through enough trauma, so no, I did not think about that. I did not think that I would be leaving AeroVironment. How that happened was interesting. I was in the movie Who Killed the Electric Car. I don't know how the contact was established between Chris Paine and myself, but basically it was a thing that he said, "Well, we're doing some stuff because of the demise of the EV1, and we'd like to be able to get you on camera a little bit at AeroVironment. Would that be okay?" I almost got permission to do that [laughs] and Chris Paine was there and filming me, and I wasn't getting work done, so there was kind of a balance between how much time I could spend with Chris before he was told to leave. He had taken probably a couple hours' worth of filming of me, and then, oh, months later, he came back and he said, "We're going to have to do all this over again." What had happened is Dean Devlin got involved with Chris Paine, and Dean said, "What you've done so far is nice, but the video quality is not good, and you need to do something a little bit more professional," so they re-filmed everything and came back to AeroVironment a second time. I guess I had practice from the first time.
Then, because of this movie, I was asked to go on tour for Sony to these screenings that took place before the movie was actually released. At one of these screenings, I met a guy by the name of Martin Eberhard. He said, "Wally, I know all about you. I want you to work at Tesla." I had maybe a week or two earlier heard the name Tesla. I didn't know much about it. I indicated I was very happy where I was. Then Martin Eberhard met me at another screening. I think the first one was San Francisco, and the second one was Seattle. He said, "Wally, I really want you to work at Tesla. You could help us a lot." I realized I needed to do something to get this guy off of my back, because here he's following me to these screenings. I figured that what I would do is give him some requirements that he couldn't meet. I gave a salary requirement but the main thing I wanted was an R&D center set up here in Pasadena that I would head up. He said, "I'll talk to the Board of Directors and see what we can do." He came back to me and said, "The Board of Directors agrees to do this."
I didn't ask for anything in writing. I felt that it was very sincere. Then I went up to visit Tesla where I was interviewed by the rest of the engineering group, and then after a while, I decided, yeah, I would make the move. I knew they had some funds. They had been successful in that, more so than I had been, for sure. [laughs] This was 2006. Originally I never thought of leaving AeroVironment. I left AeroVironment in September of 2006 to work at Tesla, never asking one question that I should have asked, and that is: Would there be a chance that Martin Eberhard would be asked to leave the company? I thought that he's the founder. I did not know of Elon Musk as a cofounder. At that point in time when I started at Tesla, I knew of Marc Tarpenning and Martin Eberhard as founders. I had heard the name Elon Musk in connection with investment, so my view of Elon Musk was that he was a businessman, not an engineer. After I was up at Tesla, I met Elon. In talking with him, I did not think that he was that literate in engineering. Later, Alec Brooks joined Tesla, and he had a long meeting with Elon Musk. Alec's view right after that meeting was that Elon did not realize what the limitations were, that he was trying to do too much all at once in terms of getting the costs down, the performance, the range, all of these things. Alec felt that that was unrealistic.
As we look back—and I will say this—I did not appreciate Elon Musk, I didn't understand him, and I still don't. He's still much an enigma to me. Clearly Elon has some understanding of business that I think a lot of businesspeople don't have. People that worked with Elon would often say, "Oh, Elon does not understand risk. He's taking chances. He's putting the company continually in the crosshairs of disaster." Yet it seems when you look at SpaceX and Tesla that Elon Musk has known exactly how far he could go to the brink of bankruptcy, within a step of it, and he knew where the boundary was in some way. I think he has some talents, and he may not even know what his talents are fully, but he also has engineering talents that Alec and I did not appreciate, and it took us a while to realize that. Alec, I think, has a more generous perception on Elon Musk's engineering capabilities now.
ZIERLER: Many more questions about your decision to join Tesla, but to go back to the documentary Who Killed the Electric Car, first, what is your sense of Chris Paine's motivations? What was he trying to convey in this film?
RIPPEL: I had the opportunity to talk with Chris Paine, so I'll first tell you what he said. He had an EV1 and he really came to love it. When the time came, when General Motors said, "We're taking it back," he didn't want to give it back. He wanted to buy it. He wanted to do anything. The first thing he did is he contacted an attorney, and the attorney said, "Look, I've looked over the paperwork. You have to give this vehicle back. If you don't, you can end up in jail." [laughs] Chris Paine realized he had to give the vehicle back, and he knew other people that felt as he did. Then he asked himself the question, "What can I do?" He thought, "Well, I've made some films before. That's what I'll do." He had at his disposal $50,000. He decided to put $50,000 into making a documentary. $50,000 may sound like a lot if you're going out to have dinner someplace, but in the film business, it's not much money to do anything with. But there's an interesting and important lesson: Chris Paine did what he could with what he had. That led to a steppingstone where Dean Devlin, who had money, said, "You've got to do this better." Dean joined the effort. He wrote a check for a million dollars so that they could make the movie as it later turned out to be. And the movie had influence. It is probably one of the documentaries that people will remember for a while. There's a lesson there, and that is, don't wait for perfection. Sometimes do with what you have, what you can do. In a way, that's how AC Propulsion got started. We didn't have all the resources by any means. In both cases, there had to be some sort of steppingstone effect. In the case of AC Propulsion, the steppingstone effect was Tesla. [laughs] In the case with Chris Paine, the steppingstone was someone from the industry who saw this and came and gave him support, and he was able to do something that he couldn't have done otherwise. So there is a lesson: do what you can with what you've got, and many times, that leads to the next step, whereas if you wait for all the i's to be dotted and t's crossed, you may never get started at all.
ZIERLER: For you, in answering the question that's the title of the documentary—Who Killed the Electric Car?—with a broad lens, given the fact that you obviously believed in the technology, both from an engineering perspective all the way to a climate perspective, given the fact that GM had created this loyal fan base, that there were regular people out there who loved driving electric cars, the fact that GM was determined not only to grab them all back but to crush them, what does that tell us both about GM, about American car culture and industry, and even more broadly, about U.S. corporations and their aversion to risk?
RIPPEL: You've got a lot for me to answer there. [laughs] First of all, with regards to crushing, this was not the first time cars were crushed. Many times, GM and other companies will develop a prototype vehicle or some small number of things where they will deliberately crush them so they don't have to worry about future liability. I think the concern that the legal people had is if these vehicles are out there, the batteries are going to have to be replaced at some point, and there will be liability. Here you have 350 volts, people are doing something, somebody gets electrocuted, and even though GM stopped building these vehicles, they will be liable. So I think there was some rational side for crushing the vehicles. I hope I don't sound like I'm taking GM's side too much.
Where I parted company is that they wanted to crush the technology [laughs]. The rational thing for them to have done, I believe, is to have, yeah, called the vehicles back, but then put together a robust engineering program to continue forward, so that they would be able to be ready when the time came where they could maybe make something and sell it at a profit. I don't think they've ever really put together a world-class effort for development of batteries and electric vehicle technology. The main thing I felt was the lack of vision, lack of corporate vision, and I used those exact words in the movie. That they lacked vision, and that's what killed at least the General Motors component of the electric car.
Vision is an interesting thing. Children have vision in the sense that they see where the target is. "Let's go to the moon. Let's cure cancer." Seeing the target is one thing, but the real vision is where you see a pathway between where you are and where that target is. That's the hard part, is that pathway, and that takes a lot of work. When I feel they were lacking vision, they were lacking that ability to put that pathway in place. I think that may still be lacking today. General Motors has a vision for—or they say they do—for all cars being electric by a decade or so from now. But they also need to expand that vision with a pathway, the pathway that will develop the super-battery technology. Many people's vision on these things is, "Well, we'll get batteries from Panasonic or LG Chem or somebody like that, and there will be better batteries then." If you really believe in something and you're a car company, I think you need to say, "We are going to take the needed steps and develop the technology."
It's like Bell Labs developing the transistor. That to me would be real vision, is to first of all understand physics well enough to be able to say, "Okay, there's a lot of room for improvement. We're just getting started." Sometimes vision is not only seeing how good it can be in the future, but to realize how bad it is at the present. If you were around a time of the Wright Brothers, true vision would be two things, really—to see how bad the Wright Flyer was, and to see how good it could become. I think this is true with electric vehicles. Progress has been great, but we need to see electric vehicles in their infancy, right now—that one day an electric car with a 300-mile range will be considered something quite inferior, and an electric vehicle that sells at the same price as a gasoline vehicle will be overpriced. Again, it's not just seeing those endpoints but seeing a pathway that will lead there.
ZIERLER: What about the fact that Ford and Chrysler were watching this from the sidelines and they chose not to jump in? What does that tell us, as I was asking more broadly, about American car companies at that point?
RIPPEL: Car culture is very different from Silicon Valley culture, and it's different from aerospace culture. From the best I can see, and I got a little bit of an interior view working with General Motors, car culture is incrementalism. You look at the market at the present time and you say, "Okay, what are the trends?" The car should be 1% longer, the car should have 2% more power. The shade of red should be a little bit different. The wheel coverings should be a little different. That's incrementalism. When technologies become mature, or at least they're perceived to be mature, that's kind of what you do. Car companies were not in the business, for the most part, of inventing a new internal combustion engine. They were using all these things that were pretty well understood, and they were focusing on the little changes that you make year to year to be current with the current trends and so on. When Ford or Chrysler or anyone else would look over their shoulders at what GM was doing, they'd say, "Look, GM is not making money on this. They're losing money on the EV1. Why would we want to do the same thing? And we don't want the state of California or other places forcing us into this, so we're going to join General Motors in opposing the ZEV mandate." So I think it was all very simple. You looked at the money. You did not have an understanding of technology or a vision of the technology. And so what they did, I think, was rational given that they were in that position.
ZIERLER: As you know, Wally, the Japanese car industry got a toehold in the United States during the oil crunch in the mid 1970s with their fuel-efficient vehicles. Are you surprised in retrospect that they did not see a moment of opportunity when the electric car was killed by GM?
RIPPEL: That's a complex thing, and I've been trying to figure that out. Toyota obviously took the lead with the Prius and they've done some very good work. At the same time, Toyota, at least by some reckoning, is the most anti-electric vehicle company of any of the major car companies. They have opposed some of the requirements that we would have pushing for electric vehicles or so on. I've tried to understand that, because on one hand, they seemed to have a pretty good base technologically. They're working now on an advanced battery. We don't know if that will be a success or not. It's possible that there's something that we don't understand. A clue to that is that Toyota has been focused heavily on the fuel cell vehicle. If you think electric vehicles are not going to make money, why would you think fuel cell vehicles would make money? Because they have a higher mountain to climb. The problems with fuel cells are a lot greater than with batteries in terms of trying to make a total system that is economic. Just the fuel costs become a problem. I've wondered—and I'm just wondering out loud, I have no knowledge here—I've wondered whether there are alliances with fuel companies, with oil companies. Japan depends very heavily on importing oil. Is it possible that they're doing things so that they do not want to offend oil companies? I don't know. It's just that what I've seen Japan doing and Toyota doesn't make sense. Given their capabilities and resources, I would expect them to be pushing more for electric vehicles than they have.
Tesla as a Viable Company
ZIERLER: A technical question, just so I have the timing right—by the time you appreciate that Tesla is a viable company, and you decide to jump on board, are lithium ion batteries fully understood to be the way of the future? Is there any relevance for lead acid at this point in electric propulsion?
RIPPEL: No, I think going back to somewhere around 2004, it was very clear that the lithium battery would be the answer. Now, they were a lot more expensive, especially then. If you go back to 2000, lithium batteries were selling for something around $1,000 a kilowatt hour, and lead acid batteries were a little over $100 a kilowatt hour. You were paying a lot of money to get the benefits of a lithium battery. But I think it was also clear that the rate of improvement was steep enough that if you looked ahead five or six years, you'd see lithium batteries that would be reasonably priced and continuing to improve in engineering terms, energy and recharge rates and things like that. I know when I was still at AeroVironment, before I left AeroVironment, the president of AeroVironment, Tim Conver, was very uncertain about lithium batteries because of the safety factors and the liability. That remains an issue, of course. Cell phones catching fire still does happen occasionally. The rate of lithium-powered electric cars burning is actually less, I'm told, than gasoline cars. That probably has given some confidence that the safety is good enough, and it'll get a lot better if we have a solid state version of the lithium battery.
ZIERLER: Is your sense, in your early discussions with Martin Eberhard, that he was inspired by the tzero and simply wanted to take what the tzero represented and scale it up into a car company? Or did he want to take it in a particularly different direction?
RIPPEL: That's a good question. He was inspired by the tzero personally. He had gone through a divorce. As he jokingly said, "When you get a divorce, then you've got to do something. You get a sports car to compensate." He joked about that. His first thought was personal, having an electric sports car. I don't think that at the outset he had aspirations to form a car company, and I think that he had some financial resources to work with. I think that evolved. I don't fully know the motivations, but he was like Elon to some extent. They both were aware of climate change, and they had those concerns. Understanding people's motivations, though, is complicated, because often we will doctor things up to make it sound better. [laughs] "My motivation was to do good for humanity." But you don't want to say what some of your other motivations were, because it doesn't sound as good. [laughs]
ZIERLER: Do you have any insight into how Martin and Elon Musk initially connected?
RIPPEL: My understanding is that they were brought together at the well. They were brought together at AC Propulsion. That was the meeting point.
ZIERLER: When you talked to the engineers, during that initial tour, what impressed you at Tesla, and what might have given you pause?
RIPPEL: There's a number of things. I've got to tell you an interesting story because it connects with my interview. At AeroVironment, I told you I developed this inverter technology, and it had application to electric vehicles, but it also had application for stationary things, like uninterruptable power, solar inverters, and things like that. I thought it would be good if we could partner with International Rectifier, the company that was making the power semiconductors. I knew International Rectifier going way back to the electric car race. I set up a meeting with the chairman of the board of International Rectifier, Alex Lidow, and key people from AeroVironment went with me to this meeting at International Rectifier. The first thing, it was really interesting—Alex Lidow, in a stroke of humor, he introduced me to each of the people at AeroVironment. He said, "I want you to meet Wally Rippel" and he told them what I've done. [laughs] It was a humorous moment. I thought at that moment, "This has got to be the best meeting I've ever been in."
I gave the presentation. It was about our so-called alpha technology. I couldn't think of a term so I called it alpha, the packaging of IGBTs. I had built hardware. We were building product using it at AeroVironment to some extent. The idea was to in some way partner with International Rectifier. I had this nice slick PowerPoint presentation, and I'm about halfway through, and Alex interrupts me and he said, "Wally, I've got to stop you. Our parts are not going to work in that application." He started telling me why his parts wouldn't work, and I'm in the position of saying, "Well, we've gone through all these tests, and it looks very good." But shortly I realized, "This isn't going to work. I can't convince the CEO of International Rectifier and say yes, your parts are good when he's saying no, they're not adequate for that application."
The meeting ended, and Alex Lidow said one other thing before we left in kind of great discouragement. He said, "You know, I have never championed solar-powered anything. Solar cells require more energy to manufacture them than they produce over their lifetime." I knew that wasn't true, but I wasn't going to argue with him. So that meeting at International Rectifier, which started out to be the best meeting in the world, ended up being the worst meeting in the world. And why do I tell this story? Because when I was interviewed at Tesla, they were telling me things to impress me. They told me that they had $60 million in the bank, and that they thought that that might be enough to get the Roadster into production. But then they told me about the deal that they had worked out with International Rectifier, and with Alex Lidow, and it was the exact same parts [laughs] that Alex Lidow had said, "No, those are not suitable" in virtually an identical application! What I figured out is that there was some deal that had been worked out between International Rectifier and Tesla, and Alex wanted to kind of bring a halt to things with AeroVironment because it would become awkward, or he would have had to tell me that there was a deal or something like that. It was an interesting moment in my interview at Tesla, realizing why that meeting with International Rectifier had ended as it did.
They discussed a little bit of their technology of how they cooled the battery and different things. There was no NDA in place or anything at this point, and there never was, actually. As I continued to learn more and more, though, I was aware that they did not understand that much of what AC Propulsion had done. They were copying the technology. At that point, they didn't understand it. They understood it maybe in bits and pieces, but they didn't have a comprehensive understanding. Maybe that was the reason why they wanted me to join the company. I started out with some enthusiasm, and then after I was working there, that enthusiasm diminished on a linear basis. [laughs] When we got to the end of 2007, I was pretty sure that Tesla was going to go bankrupt. One of the things that stood out to me is I saw all these cars in the parking lot, 300 cars or something, and I realized, "None of us here are building anything. This is just so that we can get contracts with companies overseas to build things."
I had a rough understanding of the logistics, for example that body parts were coming from England, and then various parts of the drive system were being built in Taiwan and other places. Things were going across the ocean back and forth, all adding to time and cost. It seemed to me like a very inefficient process. I remember talking to my wife—I think it was at the end of 2007—saying, "I think I'm going to leave Tesla. This doesn't make sense." She encouraged me to talk to Alec Brooks, which I did, and so I stayed on at Tesla. Then in early 2008, I was asked to leave. I was asked to leave at a time that the company really was very close to bankruptcy.
ZIERLER: It wasn't too painful for you, anyway?
RIPPEL: No, no. The thing that surprised me, and it greatly surprised me, is that something happened after I left. I jokingly have said, "Things got so much better for Tesla after I left." [laughs] I did not expect the Tesla S to be anything as it was. The engineering quality was an order of magnitude better than what I was seeing in the Roadster. I guess I had been involved in some of it, with the motor design, but the detailed stuff, I was not knowledgeable on who was doing what, and how they brought all that together. Keep in mind when I left was the transition from Martin Eberhard running the company to Elon Musk running the company. Under Elon, a lot of changes took place such that the company really started to do things in a more efficient way. The manufacturing overseas, all of that was terminated. I think the quality of engineering and the engineering processes were greatly improved. Elon singlehandedly, I think, changed the course of the company, without question. Martin Eberhard almost admits it.
ZIERLER: For you, for the brief time that you were there, what were you working on? What were your contributions at Tesla?
RIPPEL: When I first came there, I thought everything was pretty much in place for the Roadster. But they had this idea with the two-speed transmission, and the stuff we had developed at AC Propulsion was all fixed ratio, no shifting of gears. They needed a way of shifting the gears quickly and not with conventional hydraulic techniques, so the first thing I was involved with was a gear-shifting solenoid and trying to design the magnetics for that. But in the course of doing that, I started thinking, "Wait a minute. Why don't you just build a bigger motor and stay with the fixed ratio?" Because there's a lot of problems with a shifting transmission, especially if you try to do it quickly and you want high efficiency. They wanted things simultaneously, which are hard to get. They wanted fast shifting. They wanted high efficiency. They wanted it to be not too expensive. They were working with a company that just couldn't provide that, and I don't think anyone could have. On the other hand, a little bigger motor was an easy thing to do. I brought that up in an engineering meeting. I think I mentioned that. I said, "The real solution to this is just build a little bigger motor." I said, "It's not that difficult to design a new motor." The impression that Martin Eberhard had was that the motor was a tremendous effort, and that the motor was something you take as a given, you don't take as something that can be a variable. I argued against that in this engineering meeting, which everyone in the company who was an engineer was there. I got a cold response. I tried to add some levity by saying, "I worked with General Motors, and sometimes they were slow in accepting new ideas." Then I paused and I said, "But you guys are worse!" [laughs] It didn't work. The silence just continued. [laughs]
A week later, J.B. Straubel, the chief technology officer, invited me out to lunch. I thought he was going to ask me to leave the company. Instead he said, "Wally, I want you to make the motor. I've got a budget for you. Make the new motor." So I did. We got the motor built, and we got tests ran. I ran tests working with Drew Baglino, who is now the new CTO of the company. The motor worked pretty closely to what the math said it would, what the engineering parameters said it would. That was a success. But then they realized they're not going to use the new motor anyway in the Roadster; they're just going to upsize the inverter and the thermal problems be damned, the car will be good enough. That's what they did, and the Roadster worked. But if you had a Roadster and you got on a long upgrade and you drove it 80 miles an hour, the motor would overheat, so they should have had the bigger motor. But the bigger motor that I designed I think was the cornerstone of what they used for the S car. The motor in the S car was not identical to what I had designed, but it was very similar.
ZIERLER: Did you have a chance to drive both the tzero and Roadster, and can you comment on their distinctions?
RIPPEL: Oh, yes. In both vehicles, you really are aware of speed, because you're very low to the ground. They both were noisy vehicles. In the case of the tzero, you had a good deal of road noise. Actually, that adds to a sense of character. Sports cars are not quiet cars, usually. Driving the Roadster was kind of exciting, and likewise with the tzero. They were similar. The Roadster was a more polished vehicle. The body style was much, I thought, better looking. The tzero had a little better performance. It was a lighter vehicle. On the other hand, the tzero was not crash-worthy. It didn't have airbags. The Roadster was a logical next step. But the Roadster was almost an exact copy of the AC Propulsion drive system, and as such, the drive components were really not production-level components. They were almost production-level.
ZIERLER: I asked about your feelings when you left AC Propulsion, and now I'll ask about your feelings when you left Tesla. Comparing the two, when you left AC Propulsion, did you feel like that was more viable than when you left Tesla, thinking about if Tesla was more viable?
RIPPEL: Wow, that's an interesting question. When I left Tesla, I believed that the company was going to go bankrupt. I had a stock option so that I could buy $4000 of stock at 20 cents a share. I told my son, "I think this would be a good way of wasting $4,000." My son said, "I have $4,000 that I've saved, and I'm going to buy it." And Eric did buy it. He used virtually all of the money investing in me. When he sold the stock, it was a million dollars, and he has used all of that in connection with patents and so on. My son has had a strong belief in his dad that's uncanny. [laughs] But at any rate, just to answer your question, when I left Tesla, I felt that I was leaving a ship that was about to sink, whereas when I left AC Propulsion, I was leaving a ship that was—the engine wasn't running, but it wasn't sinking. It was not going anyplace, but it wasn't going down. Whereas when I left Tesla, I felt I'm leaving this just as [laughs] it's going to go underwater. Apparently, my estimation was correct. The company was very, very close to failure. One of the things that saved it was the ability to get federal money that was enabled because of the economic downturn. If General Motors wouldn't have taken that money, it wouldn't have been available to Tesla. The needs of the American car companies was something that the collateral effect was to save Tesla. So yes, it was very close to failure.
ZIERLER: At this point in your career, thinking about your next chapter, leaving Tesla, was retirement an option? Did you specifically want to stay in the workforce?
RIPPEL: Retirement was an option. I had received an inheritance. My parents had passed away. I was in a better position then, than earlier. As you know, I went back to work at AC Propulsion. I was working there just as an engineer. I was not part of the management. I was having fun. I kind of enjoyed it that way more. What's interesting—and I guess I didn't talk about it much—is what was it that we did, what was it that Alan and I and others accomplished, starting with the Impact and carrying through. It's rather interesting; if you go back to 1987, 1988, when this was getting started, electric vehicles were still using DC brushed motors and they were at low voltage. The idea of having an inverter in a car was not something that was accepted yet. I was working on this at JPL and the contact at JPL who was knowledgeable of what we were doing, he said, "Wally, to be honest, I don't think you'll ever see inverters being used in automobiles." Now of course every hybrid vehicle and every electric vehicle has at least one inverter, and more than that, when you look at the Teslas with multiple motors, and so on and so on.
Then the other thing that was not accepted at the time was high voltage. The high voltage was already considered anything above 100 volts, and the idea of going to 350 volts was not accepted. I remember giving talks at Hughes Corporation. They were very dubious about that. There were technical reasons why we went from 100 volts to 350 volts. Without that transition, we would not have had the high-performance electric vehicle that we had both with the EV1 and with the Tesla vehicles and so on. One thing that I worked on that has not been accepted is in connection with recharge, the integrated recharge. People are doing low-power recharge but not anything high-power that's integrated. The other thing is, all the car companies including Tesla now use isolated chargers, which cost a lot more. It's a lot more electronics. It triples the cost of the charger. The reason that's done is supposedly for safety, yet Alan and I have concluded that you can get equivalent safety without having to do that. So there's some areas where we did development that was not accepted, and other areas where it was accepted. But we'll see. The issue of the non-isolated onboard charger may still come to pass. We'll see what happens.
ZIERLER: From the outside looking in, when did you realize that Tesla would not go bankrupt, that it would be viable, and that maybe at some point it would even go on to become a smash success?
RIPPEL: When the stock price started going up. [laughs]
ZIERLER: The stock price doesn't lie. [laughs]
RIPPEL: Yeah. I remember when the stock got up to, I don't know, $50 or something, I said to Eric, "Well, it's overpriced. Selling it now—" And when he sold it, it was basically a million dollars. I said, "It's probably the best time to sell." [laughs] It has gone up many times that. It was a real surprise to me. I did not expect Tesla to do as well as it did. A lot of people including me felt that if they were a success, then their very success would be a challenge because the car companies would gear up and would be able to overpower them. It wasn't that long ago that people were saying, "Well, you wait and see. When VW or Toyota or GM starts making electric vehicles, it'll be over for Tesla." And now, what you hear a VW or a GM saying is, "We believe we can catch up to Tesla." That's their vision. [laughs] It's not likely that that's going to happen very soon.
ZIERLER: What was your first purchase, just as a civilian consumer as it were, of an electric vehicle?
RIPPEL: Well, just recently I bought the Model 3. Now my son Eric is driving it most of the time, and we're probably going to be able to buy a second car, which will be his, and then the car that he has, which is really mine, I'll be driving. But he drives a lot more. With the COVID virus, I've been pretty much here at home, and he commutes from Hollywood daily to here in Altadena. He's putting the miles on, so I figured it's best for him to have it. He loves it. He now informs me on what's happening worldwide with electric vehicles. He's much more knowledgeable of what's taking place in terms of the corporate world than I am.
ZIERLER: Just to bring the narrative up to the present, from 2008, what were you working on at that point?
RIPPEL: At AC Propulsion?
RIPPEL: Or you mean between 2006 and 2008, or from 2008 to when I left AC Propulsion in 2014?
ZIERLER: So I understand the chronology, you leave Tesla in 2008, and you go back to AC Propulsion?
RIPPEL: Yes. At AC Propulsion, what happened is AC Propulsion had a great opportunity. They worked with BMW. BMW basically bought over 100 drive systems from AC Propulsion to incorporate in Minis, to make a small test fleet so that they could evaluate all sort of things—public response, the technical issues, and so on. I was at AC Propulsion doing stuff with dynamometers and stuff to facilitate that effort. I was doing engineering and enjoying it.
ZIERLER: In what ways had AC Propulsion changed in those many years since 1992?
RIPPEL: It had not changed in culture at all. It had lost some because Alan was only peripherally involved. Alan was the genius behind it all, and without Alan, things were then at a static point, sort of carrying forth what he had done earlier but not really adding to it greatly. Then there was a little sadness in that. To do great things, you've got to have the key people, and Alan was—he's someone very gifted. Hard to work with for some people, but extremely gifted. Getting to know Alan has given me insights about how to make things happen in technology, and it's very contrary to conventional wisdom.
ZIERLER: Do you feel like AC Propulsion missed an opportunity at any point, where Tesla ate its lunch, so to speak?
RIPPEL: Oh, absolutely. AC Propulsion could have been Tesla, and they could have been Tesla right at the point where Elon Musk and J.B. Stroebel and Martin Eberhard were there. They could have joined forces. Any number of things could have been done.
ZIERLER: But isn't Alan Cocconi's contrarianism and aversion to corporate culture, wouldn't he have prevented that from happening? Or you don't think so?
RIPPEL: No, Alan was already essentially outside of the company. He was giving inputs, but Tom Gage was running the company. The question I have to ask is, had I stayed with the company, and had I remained the president, what would have happened? Well, if I had been successful in raising money, I think that the course might have been better, because I think I had more of a vision for the high-performance passenger vehicle than Tom Gage did. Tom Gage was conservative, and I think was looking at doing something that didn't require that much of a stretch.
ZIERLER: In 2008 and 2009, it's still very early in the game. Were there any serious talks at AC Propulsion about becoming a competitor to Tesla?
RIPPEL: I don't believe so, no. Now what I'm told, and this is all second-hand information, when the agreement was worked out between AC Propulsion and Tesla with Tom Gage, and that provided a million dollars of transfer to AC Propulsion plus a royalty agreement where they'd get paid approximately $100 for each vehicle that was produced, but using patents that AC Propulsion had—when that agreement was put together, Tom Gage spoke to some of the other people at AC Propulsion and asked a question, "What do you think is going to happen with this group forming this new company?" They all answered the same thing—"Probably nothing." It probably would lead nowhere. That was their guess, is that it wasn't going to succeed.
ZIERLER: What was AC Propulsion's business plan at that point, then?
RIPPEL: I think the business plan under Tom Gage was to produce the eBox, to get enough funding that they'd be able to produce these, maybe in 100 vehicles a year, and use this as income, and also maybe as a showcase for the drive system.
ZIERLER: Where did you slot in during this time? What were your contributions?
RIPPEL: My contributions between 2008 and 2014 Well, there were some technological things. I developed some things that were patented and techniques for drive systems that no one has used, but I think if people looked over the patents and stuff, there would be some value there. AC Propulsion did not market the technology, and I would fault them for that.
ZIERLER: What was your sense of timing in 2014?
RIPPEL: I was about to turn 70. I would turn 70 later that year. My son encouraged me to leave early. He had these funds, and he felt that we'd be able to accomplish a great deal. The technical progress was slower, and I think Eric overestimated some of his business capabilities. On the other hand, the story is not over yet. We're continuing to work, and we're putting together a technical presentation. The focus that we now have, rather than on motors and on drive systems, is on high-rate charging. An idea of mine, which I feel is the best idea I've ever had, is the cornerstone for that recharge technology. We'll see where that goes. We're open to licensing the technology, to building components, to doing any number of things, based on what reception we get with our technical presentation.
ZIERLER: Did you have this vision right at 2014 or did you want to embrace retirement in a pure sense, to some degree?
RIPPEL: I think Eric had more of a vision than I did. I think I was a hero to him. It's an incredible story. He has been very much a believer in his dad, at times much more than his dad has been a believer in his dad. [laughs] We'll see where that goes.
The Mainstreaming of EVs
ZIERLER: In the past seven years, what has surprised you the most about the burgeoning availability of electric vehicles to consumers worldwide?
RIPPEL: That's a good question. I have to say, seeing the electric car killed a couple of times, and at times hoping for its survival, what has surprised me the most is to see what in fact happened with Tesla. That the market value of Tesla is greater than the sum of General Motors, Toyota, and VW is hard to believe. That you hear Wall Street people talking that the future is electric vehicles. There's no question about that; it's a matter of who and what and where. But they all see it as a perfect storm where government regulations, private-sector technological development, are all converging on making electric vehicles a very hot item for the future.
In the past, I remember giving talks, pep talks, on electric vehicles. Some people would say, "Well, I'm not sure I believe that electric vehicles are going to be the future the way you say." Now if I would give that type of talk, people would be saying to me, "Why didn't you give a talk about the future? You're telling us only what is happening, and it's obvious to everybody." There has been a tremendous change in perception during these last six, seven years. I had the vision going back to my JPL work where electric vehicles would be fun to drive, they would have performance, and where sharing that vision with fellow engineers was very difficult. The idea of an electric car having more than 50 horsepower seemed somewhat ludicrous. Today, the fact that the Tesla vehicles, the Model S Plaid is the highest performance vehicle you can get that's street-legal is quite astounding. A lot has happened. Yet a lot still has to happen and can happen, as allowed by the laws of physics. I'm hoping to be able to talk about kind of full circle, bringing it back to Caltech, and what Caltech's vision is for all of this.
ZIERLER: Now that you're involved in a fledgling operation with your son, given the fact that it's small and in some ways it's a scrappy business venture, what does your current work evoke most about earlier aspects in your career, maybe even going all the way back to 1968 and the VW Bus?
RIPPEL: The first thing is that the word "tenacity" comes to mind. To do new things in technology often takes a lot of tenacity, and we lose sight of that. When the technologies become developed, it seems simple, and we lose sight that there's a high price people have to pay. The dues are high for developing new technology. I've experienced that, when I look back to the painful times at AC Propulsion, the painful times earlier. Then I realize that as much pain as I've experienced, Elon Musk has probably experienced even more. These things do come at a price. You have to have vision, understanding, and it's a lot of hard work to make something happen.
ZIERLER: What's your dream for the future with this company? What do you hope to achieve?
RIPPEL: To some extent I see Enure, the company we have, as something I'm handing to my son to carry forth the vision for electric vehicles and to carry forth the vision of doing new things. I never want our vision to be that we're going to be as good as Tesla. If that is ever our vision, then we will have failed. Our vision has to be that we're going to do some things that Tesla doesn't even think about, and the battery area is ultimately that. The vision I have is that ultimately Enure will be involved in some of the new battery technology. Maybe the term "battery" is not the right term; maybe it's energy storage.
There is, from a physics point of view, tremendous opportunity, space, for improving. This is one of the things physics does, is it tells you what you can do and what you can't do. Physics will tell you, "Don't try perpetual motion; it's not possible." On the other hand, when it does tell you that you can do things, you can look quantitatively and say, "Okay, how good could this become? How good is it now?" That is many times a very inspiring thing. If you would have thought about the physics of airplanes, when the Wright Brothers had their flight and you would have asked the question, "How far could an airplane fly on fuel that it could carry?" if you would have taken a poll in 1904, I'm willing to bet that you would have gotten a lot of people saying, "Less than 100 miles." [laughs] The idea that an airplane could fly 10,000 miles without refueling would have been unbelievable to most people at the time. The fact that an airplane with 300 passengers could fly at 75% the speed of sound would have been considered unrealistic. Those things, though, to a person really understanding the physics, they would have seen that those things could have been done. That's how I feel with batteries. The battery that will provide the 1,000-mile range is not that far away. The battery that will cost a quarter what the present battery costs is not that far away.
But we do have to approach these things more from a fundamentals point of view. This is why I felt that Caltech is a strong contender to do this. The Caltech at least that I knew in the 1960s when I was there really encouraged us to look at things from the most fundamental points of view, from the atomic world starting outward, and from equations rather than from looking at business plans. So I think that Caltech could play a major role. But as I see Caltech right now, I do not think that batteries are an important thing on their horizon. There are some efforts at Caltech, but they're very small compared to their primary effort, which is the artificial photosynthesis. While Alan is bothered by car companies making cars that are less efficient than he feels they should be, I'm probably even more troubled by something where the efficiency numbers are off by a factor of four. If you look at what the goal is with artificial photosynthesis, the goal is to create fuels that in many cases would be used in internal combustion vehicles. When you look at the end-to-end—you start out with a certain amount of land surface being used to collect sunlight—that land surface is several times greater than if we simply use solar panels and electric cars. I'm troubled by that. The largest gift in Caltech's history was given to Caltech for the sake of dealing with climate change. While I think that that gift may be applicable to aviation, I don't think it's the right way for transportation. I think that just from a point of view of energetics, you start out with a process which converts sunlight to a fuel, and the best numbers we're hoping for is that that will get to 20%. Then you have the issues of using that fuel, where internal combustion engines are less than 30%. When you compare that to solar energy, which is converted into electric power going through batteries that are 95% efficient, the amount of land surface used for the artificial photosynthesis, the amount of land surface per vehicle mile, is three or four times as great. I think that is an ultimate economic issue. Where does that land come from? We take it either from forests, which we need—forests are sinks for CO2—or we take it from agriculture, and we're going to grow less food. I don't know where that land surface comes from to produce, inefficiently, energy with artificial photosynthesis, so I've been troubled about this effort. At the very least, what I would like to see at Caltech is an effort on batteries that would be commensurate with the artificial photosynthesis effort. I've been able to express my piece here. [laughs]
ZIERLER: What would that look like at Caltech? Are you envisioning something like the Elon Musk School of Battery Science, or something more incremental like hiring more professors and taking on more graduate students with interests in these areas?
RIPPEL: First of all, I'd like to see it start small, but very high quality. I would like to see an effort at Caltech, first of all blessed by the Institute itself, where they would seek to get anywhere between four and ten people who would be world-class to make this happen. I would say maybe one of them would be a conventional electrochemist. I would want to see maybe a couple of crazy mathematicians and crazy theoretical physicists involved, people that think well outside of the box. History tells me that this is the better way of doing things. The electronics industry was revolutionized in just that way. Had we said, "Let's invest and get more engineers who are good at vacuum tubes," we would have had better vacuum tubes, but we would not have had the transistor. The fact that Bell Labs invested the money to really understand a solid state phenomena to the point that they made good diodes and then later on were able to parlay that into the transistor invention and continue on, I think that same philosophy is what's needed in batteries. The battery is not going to be a vacuum tube; it's going to be something new, and that will be something that comes out of the mind of a physicist more likely than just continuing on with electrochemistry. It may be a device that will look electrochemical although it's moving away from that. The lithium ion battery is less electrochemical than the lead acid battery in terms of its understanding. If Toyota is successful with the solid state electrolyte, batteries are going to start looking more and more like solid state elements and less and less like electrochemical things.
That's my vision, is that you work from the bottom with physics. Once you have a solid physics understanding of what you want to do, then you can start expanding out into the engineering world. But what we need right now is battery science more than battery engineering. We're not even ready for the battery engineering for the breakthrough battery. What we need is the battery science to get that started.
ZIERLER: We're comparing Caltech against itself. Is your sense that the academic research that you're calling for at Caltech is happening at peer institutes, places like Harvard and Stanford, or not there either?
RIPPEL: I don't think it's there either. I think in most institutes, and also in the government, when they think of batteries, they are going along very conventional lines. They're getting people that are familiar with electrochemistry, with materials science, and they're trying to build on that. And they are accomplishing things. They are making incremental progress. But the same would have occurred had you gotten a lot of people good at vacuum tubes. The vacuum tubes would be better now than they were in the 1970s if we kept working at them, but I don't think that's the answer for a breakthrough.
ZIERLER: But you are confident that if anybody can take this on, Caltech is the spot to do it?
RIPPEL: I think Caltech has the potential, yes. I know of course the Caltech of the 1960s which some of that came out of the Manhattan Project, I suppose. But I think there's also that same spirit, of looking at things in a fundamental way and not accepting the rules of thumb so much as the rules of nature.
ZIERLER: At this point, we've reached right up to the present in this wonderful series of conversations. For the last part of our talk, I'd like to ask some broadly retrospective questions about your career and then we'll end looking even more to the future. First, as an engineer, what has been the most fun you've had? On all the things that you've done, what stands out in your memory?
RIPPEL: I'll just give you a flow of consciousness on this. One of the things that was most fun was where, for a week, I became a newspaper reporter for The Star-News. As a result of the electric car race, I had some contacts with The Star-News, and I contacted them, and I said, "I'd love to be a reporter for one week, and go back to cover Apollo 17, the last Moon flight." They said, "Well, we don't have any money for that." I said, "That's okay. Do you have a dollar? If you can pay me a dollar, that will be enough." So I paid for my transportation and everything, and I was a reporter for one week for The Star-News, and I got to see the Saturn V in action. That was really a high point. Every time I've flown on an airplane, I'm always amazed at the power of takeoff, except one time, and that one time was when I was coming back from Orlando. Took off in a 707 and it felt so low-powered compared to the Saturn V. The Saturn V, experiencing that in reality was like something supernatural. I think of that as a fun time in engineering. I wasn't an engineer; I was just a fake reporter. [laughs] But it was a lot of fun doing that.
Then other things I think about that have been fun—obviously I enjoyed tremendously the thing at AeroVironment with an airplane setting an altitude record. Building something and seeing it work, that was fun. The stuff that I had done at JPL, then seeing that come alive with the early work with the Impact was exciting. There have been moments where I felt elated as a result of what I've experienced through engineering. There have been some down times, too, as I've mentioned. The belief that the electric car was about to be born, thinking in 1985 that maybe there would be something starting with General Motors, then in connection with the Impact, the EV1. For me, the electric car has died several times, not just once, and there has been those painful times. The painful times, however, have made the present time probably more valuable. If you've gone through medical problems, life becomes more valuable. The fact that the electric car has been on life support at times, I think the life of the electric vehicle now, I value it more. I cherish it more.
The only thing that causes me impatience is the need for moving quickly because of climate change, and the realization that, as good as electric cars are, they really haven't made a dent yet in the fossil fuel consumption. That's where I feel the frustration and would like to be able to play some role to see the role of electric vehicles accelerated. The only role I now know that I can play is a technical role. I don't know that I'll be able to inspire people to do anything politically. I had hoped, with my church, for example, to motivate people in wanting to take better care of the environment, and I was a complete failure in that. So it's bittersweet.
ZIERLER: I asked you about fun in engineering. From a technical standpoint, what have been some of the most difficult engineering challenges that you've faced?
RIPPEL: One of them was, interestingly enough, understanding the induction motor. At JPL, I early on concluded that the induction motor would be the ultimate answer because of low manufacturing cost and that it could be made power-dense and also fairly efficient. But the control laws for that and achieving dynamics so that you don't have oscillations and things like that, and understanding that, was difficult. I think that's one of the reasons why some of the car companies or most of the car companies have gone with permanent magnet motors, is because there is a challenge of controlling the induction motor so that you don't have anomalies, oscillations and things, especially at high speed, and with high-speed regenerative braking. That has been one of the more challenging things.
The other thing is, in connection with the work I'm presently doing, the invention I mentioned, which is a magnetics invention, was something I started thinking about when I was at JPL. Some papers were written. It was a thing that gradually evolved. It's a very simple idea, and it took a couple of decades for me to really understand what was at stake. I don't talk about it because the principles are so simple [laughs] I don't want to create problems. My son warns me about this, with intellectual property. That was I think the other challenge, is being able to understand that in a simple way that was clear. Sometimes in engineering you can make things work, but you don't understand them as you should. The goal is to understand things in a comprehensive way, to be able to write equations, to be able to be fully predictive. That's the ultimate accomplishment. That's probably more important than making things work.
ZIERLER: For students who will be listening to our conversations or reading them in the archives, in reflecting on your motivations as an undergraduate yourself, for students today who might despair about where climate is headed, or where politics is even headed, what lessons might they take in your audaciousness to rip out the internal combustion engine of a VW Bus, put in a battery-powered engine, and drive all the way across country?
RIPPEL: There's a lesson that I learned personally, and then when I talked about Chris Paine, I saw the same thing, of taking what you have and doing what you can do with what you've got. I realized that putting batteries in a car was not going to change the world, not at that point. As some of my classmates pointed out, you may be showing how bad the technology is. I think to some extent, I did. If you read the Engineering & Science magazine, I think it was made more clear that electric cars had a long way to go. People saw that the electric car was maybe not as good as they thought it was, [laughs] after the electric car race. At least some people I think felt that way. But what I have learned is if you take that first step, then the second step may be clearer. If you try to see all the steps ahead of time, that's difficult. Sometimes the pathway, the only way you see the pathway, is by getting on the path and taking steps. You try to see as much as possible of the pathway. You try to understand enough so that you know that the goal you're aiming toward is the right goal. The sad thing is if you put a lot of effort into something and after it's over, you're successful, but you realize you've gone to the wrong place. That's my concern with Caltech right now, with the artificial photosynthesis, that that effort may have limited value. It may not be the right answer in terms of what we're trying to do with climate change. It may be important for aviation, and I'm not sure about that. It may be that there will be some other answers as well. But I'm troubled when I see a lot of effort, money in particular, being spent where the goal is not necessarily the right goal. If you have the right goal, try to get on the path as soon as possible.
ZIERLER: In reflecting on all of the ways you've contributed to the creation and success of electric vehicles, how do you quantify all of that accomplishment? Is it in gallons not burned? Is it another metric? How do you think about those things at a broad level?
RIPPEL: The way I'd like to think about electric vehicles would be in terms of amount of CO2 that has been avoided. You'll often see people show these numbers—"Electric vehicles have saved so many million tons of CO2." But then it has to be put in perspective. The CO2 emissions from transportation worldwide are still increasing, and so in a sense, electric vehicles have not gotten to the point yet where they start bending the curve down. I'm going to say that progress is yet to come. The metrics of the present are not something to brag about. If 20 years from now, we've squeaked through and we've been able to avoid the worst of damage from CO2 because of electric vehicles, then maybe we'll be deserving of some credit. Yet I think we have to delay that. Delay the credit.
ZIERLER: That's a perfect segue to my last question, looking to the future, and that is, as you posed the question, what steps can we take, all of us, as citizens, as consumers, to ensure widespread adoption of electric vehicles as a solution to climate change and so much else?
RIPPEL: I never want to feel that we are locked into a solution. It could be tomorrow that we'll have a breakthrough that will obsolete electric vehicles. If that happens, that's wonderful. The main thing I feel is that people become knowledgeable. They become educated. We don't have an automatic sense of the environmental damage we're doing until we study it. I know that I didn't. Smog was the first thing I was aware of because I had tears running down my face, so that I understood. But I didn't understand that we were doing perhaps the same thing that had been done 60 million years ago, causing thousands of species to become extinct, that there was a mass extinction event that was being caused by human behavior. I didn't realize that the mass of plastic in the oceans was starting to rival the mass of fish and marine life in the ocean. I didn't realize that the biomass of forests had been reduced as much as it had. So environmental education is a key thing. Also on the plus side, education where you see what you can do. For instance, there's a lot of people that still think I suppose that solar energy is inherently less economic than fossil fuel energy. There's some people that probably think that you use more energy to build solar cells than they produce over their life, which is not true at all.
The only thing I want to see though is that rather than just knowledge, that people learn thinking skills. It's good to know things, but it's better to be able to think well. I think the things that got me on the right direction have been simple things, looking at being able to evaluate something quantitatively. These things don't require great math tools. They require sometimes just simple math tools, the ability to multiply or divide some numbers. But the willingness to do it, and out of that you can learn a lot of things. A lot of people who question climate change could easily figure these things out. They have the tools to do it. They just haven't been trained how to apply those tools, how to think. That's the other thing, and it's something that I deeply value the Caltech experience, is not so much what you learn, but how you learn to think. I hope that Caltech never loses that.
ZIERLER: On that note, I'd like to thank you so much for spending this time with me, for sharing all of your perspective and accomplishments over your incredible career. This will be a wonderful addition to the Caltech archives. I'm so glad we were able to do this. Thank you so much.
RIPPEL: Thank you, David.
- EVs and Smart Grids
- Decarbonizing Infrastructure
- From Hollywood to Caltech
- Batteries and Smog
- The Great Electric Car Race
- EVs and Batteries at JPL
- Aerovironment and the Great Solar Race
- GM and the Great EV Experiment
- The Origins of AC Propulsion
- Who Killed the Electric Car?
- Tesla as a Viable Company
- The Mainstreaming of EVs