The climate case for flying cars

we're going to get like these hard questions. Because in batteries, if there is a breakthrough, you basically have about half a dozen people in the world who can really get to the bottom of it and say yes, this works, or notice it doesn't work. And Nat, you're one of those dozen people. Yes, this is Venkott Wisanathan, a battery expert who I often turned to for help with discerning

good battery ideas from bad ones. Batteries are a crucial technology in our zero emissions future, but batteries are also complex, and many people use that complexity to create a hype around their particular idea of a battery, which turns out to be bunk. Venkott is a professor at Carnegie Mellon University and He's deeply linked to many climate tech startups. He came with Zero's producer, Christine Driscoll and I on

a tour of startups in Silicon Valley last year. We traveled in Venkott's Tesla Model three for hours that week, and we debated many things. One thing that we kept coming back to was electric aviation. Even when the world finally gets on track for real to reach net zero by twenty fifty, we'll see emissions decline from most sectors except aviation. Bloomaganny f s emitst that aviation emissions are

set to double between now and twenty fifteen. Venkat argues that electric aviation, specifically powered by batteries, could help reduce some of those emissions, and there are already dozens of companies working to make electric aircraft commercially viable. I'm not convinced, and I did give Venkat a hard time about it, because one of the first applications we likely see from

electric aviation is taxis. Flying taxis are just toys for rich people, aren't take I see flying taxis as like a roadster moment, like, did we really need yet another electric sportscar? Probably not right, but the doy for the rich people is what allows you to understand the technology, and then once you get that, Venkat is obsessed with building a battery that will power electric aircraft in overcoming gravity.

To fly a plane has to spend a crazy amount of energy, and today's planes are able to do it because jet fuel packs a lot of energy in a small weight. Batteries are one tenth as energy dens, which means you have to carry ten kilograms of battery to displace one kilogram of jet fuel. Do that and it will mean there will be no place for people on that plane. A battery that can power commercial aviation will have to be heaps better than they're pretty amazing batteries

that we can already find in electric cars today. Making that kind of battery will require many professorial brains and many entrepreneurial talents. And though I'm skeptical, there is a real movement in electric aviation. Bloombaginny F counts more than fifty aircraft operators that are interested in buying them. The total order book stands at two thousand, and because batteries are useful beyond just transport, all this work will have

many spilower effects in other technologies. For Venkard, though, electric aviation isn't just a debate worthy topic, he's divorce his career to it. Later this year, he's moving to the University of Michigan's Aerospace department, hoping to train a new wave of engineers taking on this problem. So I wanted to catch up with Venkutt to finish our debate about the use of flying cars and to talk about the scientific advances that need to happen to make the batteries

that will power up. So while we were on this trip, we talked about your vision of the future, which was tied to the nineteen sixties cartoon TV series The Jetsons, where people took all sorts of flying cars. Today you call those ev tolls electric vertical takeoff and landing aircraft. I mean, in a way, this is an interesting moment to talk about electric aviation because George Jetson, the main character in the animated television series The Jetsons, was actually

born in twenty twenty two in the fictional world. By the time you Know The Jetsons was happening, he was a middle aged man with two kids. So do you think that's the kind of time trajectory. We are thinking about where people will be flying all the time. Yeah. Absolutely, I think eventually, at the time when we reach Jetsons middle age I guess, which is around twenty forty twenty fifty, I think pretty much every individual would have three electrified

modes of transport. One is be an electric bicycle, electric scooter for sort of very short commutes, then an electric car and a personal electric VAT doll electric vertical takeoff and landing aircraft that could take them hundreds of miles. And eventually these ev dolls would probably cost about forty fifty thousand dollars, just like the purchase of a car.

So I think we're not that far off. And actually I think there is actually a straight shot from here to the Jetsons future by the time we hit George Jetsons middle age, a straight shot from here to the Jetsons future. Is that what your new job is about? Winkett? Yeah. If I didn't think that there was a straight shot from here to the Jetsons future, I would not take this bet. Now, when engineers say it's a straight shot, it means that we need lots and lots of great

engineers to be thinking about this problem. We need hundreds and thousands of people working on this problem. That's the scale of the transformation that happened in electric cars. If we can enable a similar transformation in electric aviation, I think it is actually a straight shot from a technology

perspective to get to the future that the Jetson's imagined. Now, we had this debate over the summer about whether or not flying taxis cars our climate tech, whether they will be real or not, how long it might take if they do become real, and we talked about it a lot. As you know, I'm still not convinced. But in the meantime, you have gone ahead and made a bigger commitment to

this cause, and you have taken a new job. Yes, indeed, I have decided that electric aviation is the most important problem that batteries, especially next generation batteries, can address, and so I have decided to move to the University of Michigan, which has the oldest aerospace department in the world, to try and transform aerospace for the second century of aviation, hopefully an electric future. And it's not the first time

you're trying to disrupt a university department. Universities are great places, but they're also a little bit bureaucratic and stayed and at Carnegie Mellon University you joined the mechanical engineering department as a battery professor. Indeed, about ten years ago, actually twenty thirteen, I was a graduate of Stanford looking for a job, and I applied to various places in various departments,

including mechanical, chemical, mature science. And one of the key things to a department is the kind of people that you would attract. So in a mechanical enging department, you would have people that are very excited about cars. And in twenty thirteen it was not at all clear that electric cars were the future. But I made this big bet that the future of every mechanical elenging department will be electric and in that sense, batteries are the new

combustion of the future. And ten years onwards, every mechanical eunnging department in the country has at least two to three professors that are working on batteries in some form. And you could not today have a department that does not have a plan for electric mobility, and especially try to hire people that are working on batteries. Today in aerospace there are zero people working on batteries or card

carrying battery people that are in her space department. And similarly, ten years on, I hope to have the same impact that I had mechanical engine department now in an aerospace department. So now let's define what your new job is going to be, and let's just start with defining what electric aviation really means. Yeah. So electric aviation is aircrafts that get their primary energy source from electric power, and that could be in a few different forms. That could come

from directly battery powered. That could come in hybrid form where you have a regular gas turbin that is combined then with battery power, or it could have fuel cell and fuel cells would use hydrogen. In that sense, the fuel will be a different fuel, and ideally that hydrogen comes from carbon free sources. Yes, do you remember the moment that you realize electric aviation was the problem you

wanted to work on? Yeah? Absolutely. So I did this trip in twenty seventeen summer from Pittsburgh to Palo Alto, and so I did this in my electric car. It was a sixty kilo or Tesla mardless about three thousand miles. We finished the trip in four days. And what I realized at the end of this trip was two things.

One was it was quite easy to do this trip, and the range anxiety, as I think many people had described at that point, was not likely to be true because the ease of this trip made me realize that these next generation battery innovation that I'm working on, it's not immediately obvious that automotive was the path for this,

and so I had this sort of soul searching journey. Luckily, I got a phone call from Ashish Kumar, who had then started a company trying to make hybrid electric aircraft, and I became fascinated by this because this was a clear space where I could continue working on battery innovation for the indefinite future, and there would be a market waiting for every new technology that I could unlock. And so that started my pivot to electric aviation. So it's

clear that we need to cut emissions from flying. There are three ways in which that can happen. Battery operated electric aircrafts, hydrogen powered fuel cell electric aircrafts, and sustainable aviation fuels, which are essentially fuels that you use today but made from a source that would be processed in such a way that there is no emissions attached to it, and so these are typically bio based fuels. You'll take

it from corn or sugarcane or something like that. Of course, you're a battery professor, and so you were making the battery bet here. But just from a theory perspective, why is the battery bet the better bet? Yeah, so I think if you can enable battery powered flight at the same weight, I think it would be the most energy efficient solution, assuming that you could make this magic battery that would weigh the same amount as sustainable aviation fuels

or jet fuel. Now where of course, far from that. So this is the journey I went on when I tried to ask the question is there a pathway from here to making light batteries that would have the kind of transformative impact that we are talking about here. And in that journey, we wrote this paper in Nature in early twenty twenty two and the title of that paper

was the Challenges and Opportunities of Battery Powered Flight. The challenge is obvious, right, So I think it's very clear and very easy for anyone to state the objection that batteries are going at a very slow pace. Right, If you went back one hundred and fifty years. Batteries are improving at the rate of two percent per year, and two percent per year improvement is basically how much energy can the battery store per kilogram of material used to

make that battery. Indeed, in fact, we start the paper by the description of the LaFrance, which was in eighteen eighty four, a dirigible that was powered by a four hundred and thirty five clelogram zinc chlorine battery eighteen eighty four, and that was actually one of the first controlled flight and Charles Rayner, the inventor, said that it was only a matter of time and money before electric aviation takes off.

One hundred and thirty years have passed, right, and we now have lithium ion batteries right that are substantially more energy dense than the zinc chlorine battery that Charles Raynar used. Now, if you go by that logic, right, if you're going at two to three percent per year, we have to wait a few hundred years before you can get energy

density comparable to jet fuel. Now, if you actually zoom in and look at the progress over the last thirty years, you actually realize that it's growing more like four to

five percent per year. If you go from nineteen ninety when the lithium ion battery was invented, to about twenty twenty, right, you know, it sort of grows at about roughly forty five percent per year, And you know that doubling might not seem like a lot, but just so there's context around what doubling in rate improvements can do this century.

We are currently on a path of reducing emissions roughly on about one percent per year basis, and if we do that, we will breach the two degrees celsius paris goal if we double that emissions reduction. According to a new scenario that's been published by the oil company Shell, just doubling the emissions reduction from one percent to two percent a year will keep us below the two degree

threshold and help us meet the parish agreement goal. So these doubling in rate improvements can actually matter a lot when they play out over decades. Indeed, now if you actually zoom in even more and zoom in over the last five years in twenty seventeen, the best batteries you had then where about two hundred and fifty hours per kilogram.

The US Department of Energy launched two programs, one called Ionics and another one called BAD five hundred, which shifted the goal post and they actually wanted to double the actual amount of energy contained inside the battery from two fifty to five hundred what our sper kilogram. Fast forward to twenty twenty three, you now have many credible demonstrations of cells that can deliver energy density in that range.

We're not quite there yet where you could go and buy an electric car that has a battery of that specific energy, but it's not far off from when we can do this. I think it's quite likely that within a decade, maybe even shorter, right, we would be able to get to batteries with thousand what hours per kilogram. Now, what that enables is trips to the extent of about a nautical miles quite easily. And you can ask the question, well, will there be a limit? Right? Will there be a

limit where we cannot do this? And this is the most important point, if there's one thing that I want your listeners to take away. We are far from the limit, the possible limit of the energy density of batteries. After the break, we grapple with the problems that might happen as this technology takes off. It's a difficult problem, that's clear, and in some way you agreed it is a difficult problem. When we were on the trip, you said, so it

actually aviation canonically, like everyone should be negative. That is the correct perspective to take, because you know we cannot make them work. They'll come out heavier. He's not clear whether there's a direct environmental positive impact. So all these things are good reasons for not doing this. So what

are the good reasons for doing it? The good reasons are exactly the same reasons I said or reasons not to do it, which is that you have to change the game right, So you have to make sure that they don't come out that much heavier, that they actually can make a transformative impact on the emissions because you directly power them with solar power and reduce the amount

of energy used to fly. And so the whole game is to try and understand this from a system level and try to clearly understand which aspects of aviation can actually be disrupted by electric I think in the foreseeable future, long Easton's aircraft white body aircraft will have to fly with fuels, and that's the only way that we can continue to have our lifestyle where we fly across continents, that I can now fly from here and then meet

you ostrat in London. Those kinds of aircrafts cannot be transformed to electric, but there is a significant opportunity for smaller and medium sized aircrafts all the way up to narrow body aircraft. Just so we have our definitions, four to six seats is a narrow body, yeah, about six seats yea, And then white body would be more than six seats basically yeah. And another way to think about it is the kinds of trips that you might take.

Right so, if you had a small regional aircraft, you might take a trip from let's say Pittsburgh to DC, short two hundred something miles trip. If you want to take narrow body, that would be more like the kinds of trips that you would take let's say from Pittsburgh to Denver, which is a few thousand natica miles. And then white body is something that I would take. If I wanted to fly from Pittsburgh to London, then I would take a white body aircraft. By twenty fifty, when

the world needs to get to net zero. The largest sector of emissions is likely to be aviation, so it's clearly a big problem to be solved. But you mentioned a few segments of aviation that could immediately benefit from electrification.

One of those is helicopters. Yeah. So helicopters are an engineer's nightmare and of course people's nightmare, because they cause noise pollution in the areas that people live in, they are inefficient for the fuel they burned, and most importantly, they're unsafe because they have many, many different ways of failing, where just one part fails and then the helicopter fails.

What is the joke about helicopters. The reason helicopters fly is not because of aerodynamics, but because they are so ugly that the Earth repels it, and so that's how they fly. To put it simply, there are two types of electric aircraft. One is a replacement for a plane that requires a runway to take off, and the other is called an ev toll, the electric vertical takeoff and landing aircraft. That's the one that's a replacement for helicopters.

In both cases, electric motors make less noise and consume far less energy to produce the same thrust. If these electric aircraft can become cheap enough, they could eliminate many of their fossil fuel cousins. If electric aviation only solves the helicopter problem, will that be a worthy problem to be solved and dedicate ten years or the rest of your life solving Blanquet, I think that is a good start.

I think if you are able to displace helicopters and just the helicopter market is taken over by electric I think that is still a worthy achievement. But I think once you do that, you will realize you can do things better. And I think that's sort of the journey that we have learned in electric mobility, where nobody thought that from making an electric sports car which was priced at well ower one hundred thousand dollars, that there was a pathway from there to a mass market car for

thirty twenty five thousand dollars. Right. So in the same way, I think over the next decade, it is likely that electric aviations primary focus is going to be in the helicopter market, or the market where you have small distances and people that value time a lot will be willing to pay a much higher price to travel that mile in this case, travel a mile in the air and displaced that helicopter ride. But this toy for rich people then becoming a market product. It's certainly a model that's

been successful. In the case of electric cars. You know, it's still not quite affordable. You know, you can't just turn up in India and get a mass market electric vehicle yet, but maybe that day is coming. It doesn't seem unimaginable anymore. However, what it does do is that it will open up a world that wasn't being used previously to a lot more people. So instead of us consuming less energy, we might just end up consuming a lot more energy. There might be a lot more of

these flying cars around city. Is the noise may be lower relative to a helicopter, but there are not that many helicopters in cities, and so suddenly you lower the per aircraft noise. But then you multiply the number of aircrafts in cities by a hundred times, and so is it really worth it? Yeah, So this is a great question, and in fact, this is actually one of the question that graduate student asked me a couple of years ago, which is that Vankaty, you work on problems that aspire

to have an impact on the net SERO future. So how can you work on these flying cars? One framing of that question is if you took that same trip with an internal combustion engine car or an electric car, would that consume more energy or less energy than a

flying car? Right? So the naive perspective, this sort of first order perspective, is that no way, right, the flying car should use way more energy than ground vehicles, right, because you are overcoming gravity, and you're flying in the sky continuing to overcome gravity, and that takes a lot of energy. Right. So here's where the answer is actually

quite counterintuitive, depending on the aircraft design. If you can make an aircraft efficiently light and have good aerodynamics, you actually can be compared to an electric vehicle and much better than an internal combustion engine vehicle. So you actually end up producing less energy emissions for a trip. Of course, this depends on the trip length, right, So for shorter the trip than you end up paying the energy penalty

for taking off and landing. But the longer the trip, the more energy efficient a flying car gets relative to a ground car. And so there is I think a clear energy efficiency argument to be made that a trip that you would take with let's say Uber Black, if it was displaced by an EV doll it would definitely

reduce emissions. This future is decades in the making. In the meantime, Vencott is also the person who venture capitalist call when they want to know if a battery startup has a real breakthrough and can actually deliver the product. And there are lots of companies promising battery breakthroughs. When is kept busy, it took a lot of phone calls on our trip, so I wanted to ask him when somebody comes to you and says, hey, there's this new battery idea, do you think it will work? Should I

give this company one billion dollars? What do you do? Yeah? So, I think the difficulty in assessing a new technology is to view it with some optimism with a healthy dose of skepticism. And so one of the challenges when new diligence, this is the process of assessing the validity of the technical claims made by a team. When your diligence and new technology, you have to be able to understand the core principles and see whether those core principles hold up

and whether there's a pathway to scalability. There are many many changes possible to a battery. You can change the anode, you can change the cathode, you can change the electronite, you can change the separator, you can change the current collector. You can change various things. And each of these things could lead to a better functioning battery, and those would have its own manufacturing processes that are required to scale.

And so the reason that I think I have been able to address this is over my own career, I have worked on many of these aspects, and so I know many of the common pitfalls that are likely when you try and scale a particular approach. A large portion of the reason why I can quickly diligence different approaches is that they all have to sort of fundamentally satisfy this problem that I call the end problem, which is

that they have to do all these things simultaneously. Can you give an example of where this played out where a startup had a problem that they really needed to solve. Either you provided the right kind of advice or you provided the right kind of talent that would help them

solve that problem. One of the examples that I can talk about is a project that we worked with twenty four M technologies where the battery that twenty four M is working on will be used to power those flying cars to try and set a range record that these electric vertical takeoff and landing aircraft would now be able to reach off the order of two hundred to three hundred miles as opposed to the hundreds of miles that they're limited to today. So batteries consist of three main components,

an anode, cathode, and an electrolyte. And the batteries that are used in lithium ion cells that are used in your cars and laptops use a liquid electrolyte. A liquid electrolyte is much like you know gator rate, right, There's two main components. There is a solvent and a salt. Right, So the solvent in your gator rate is water and the salt is you know, some kind of sodium or other kinds of salt. The same attribute is needed inside

a battery where you have solvents. Now, of course, lithium and water don't like each other, so you go through extraordinary pains as we saw in all of the factories that we visited to avoid moisture. Right, so batteries have

nonequis solvents. That means those solvents that don't contain water and a salt, and the salt is usually not a sodium containing salt, but a lithium containing salt, and the salt provides the mobility of lithium ions from the anode to the cathode, a cathode to the anode, depending on whether you're charging or discharging. So designing electrite is the hardest thing inside a battery because it faces the anode, faces the cathode, has to play nice to the anode.

It has to play nice to the cathode while performing its main function, which is to transport lithium through it. And this is an extraordinarily difficult challenge because the second you change any of the components electrolyte that you used for current batteries don't work. So you now need to either change some combination of the solvents or the salt to make this happen. And the challenge here is that there are over six billion molecules known today and you

could use any one of them inside the battery. In fact, you would use multiple of them inside, which means that if you had to manually test six billion molecules, we would not have any battery innovation. This is where we have a needle in a haystack problem where you have to try and find molecules from this six billion list that can provide you the functionality you need and enable the next generation batteries that we want that can store

more energy. And so this is one of the key areas where many of the research innovations from my research group at Carnegie Mellon and many of the innovations that I have been able to try late through a Onyx which was one of the companies that I had co founded, which also featured on this podcast when their CEO had a little bit of a freak event as his money was stuck in this bank called SVB, which you may have heard had a bank run and has now found a buyer. A happy ending to that story, but it

was quite the story. Yeah, it was a quite stressful weekend.

But the point you brought about in terms of being part of this ecosystem that allows me to understand what are the problems that need to be solved, the people that can deploy capital to help solve these problems, how to get the time, how to get the patients for the capital that is provided so that you can solve these problems with the right level of teeming at the right time and then scaling at the right time, and so being part of this incredible ecosystem has been a

privilege for me and has enabled me to achieve things that I would have otherwise not been able to do. It's no longer impossible to imagine electric aircraft in the sky. I still think these highly engineered devices are far away from being a climate solution, but what I find interesting is that the challenge attracts people like Venka to work on it. Regardless of the future of flying cars, the battery improvements that are bound to be made in its

pursuit will help other applications. For example, a more energy dense battery will make electric cars cheaper and help homes generate and store renewable energy for the zero emissions future. Thank you so much for listening to Zero. If you enjoyed this episode, please take a moment to rate and review us on Apple Podcasts or Spotify, Share it with a friend or someone who is stuck in traffic for too long. If you've got a comment or question, send us an email at Zeropod at Bloomberg dot net. You

can also tweet at me I am at Aukshatrati. Zero's producer is Oscarboard and senior producer is Christine riscoll. Our theme music is composed by Wonderty Special thanks to Blake Maple's Stacey Wong and Kira bin Rim. I'm Aukshatrati back next week.