Catalyst with Shayle Kann - Booking your first zero-emissions flight

Episode Date: August 18, 2022

In aviation, there’s a crowd of low-carbon technologies vying for a slice of the market. On one hand, the long-haul portion of the market will likely rely on sustainable aviation fuels (SAFs) which still emit greenhouse gasses but could be offset to net-zero. On the other hand, there’s a big share of air traffic that could go completely zero-emissions with the help of batteries and hydrogen.  So how soon could you book a ticket on a zero-emissions flight? And what routes are possible? In this episode, Shayle talks with Jayant Mukhopadhaya, a researcher at the International Council on Clean Transportation (ICCT). Jayant recently authored two reports on electric aircraft and hydrogen aircraft. Shayle and Jayant dig in on some tough questions:  Can electric aircraft take incremental steps into the market given the limitations of current battery energy densities? Or do they need a technology breakthrough? How do hydrogen fuel cell, compressed hydrogen combustion, and liquid hydrogen combustion compare? How do airports need to prepare for hydrogen fueling? Hint: Terminal-sized upgrades. Catalyst is a co-production of Post Script Media and Canary Media. Resources: Canary Media: Can battery-powered airplanes decarbonize air travel?  Canary Media: How do we clean up air travel? Fuel from fast-food grease is just the start Bloomberg (video): Hydrogen May Be the Jet Fuel of the Future Catalyst: A bumpy ride toward decarbonizing aviation Catalyst is supported by Antenna Group. For 25 years, Antenna has partnered with leading clean-economy innovators to build their brands and accelerate business growth. If you're a startup, investor, enterprise, or innovation ecosystem that's creating positive change, Antenna is ready to power your impact. Visit antennagroup.com to learn more. Solar Power International and Energy Storage International are returning in-person this year as part of RE+. Come join everyone in Anaheim for the largest, B2B clean energy event in North America. Catalyst listeners can receive 15% off a full conference, non-member pass using promo code CANARY15. Register here.

from the studios of PostScript Media and Canary Media. I'm Shail Khan, and this is Catalyst. Question for you to ponder. How likely do you think it is that you, sometime in the next decade or two, will fly in a plane that is powered entirely by electricity or, alternately, a plane powered by hydrogen? Let's find out what stands in the way

between you and your zero emissions flight. When utilities need flexible capacity, they can count on, they turn to Energy Hub. Energy Hub works with more than 170 utilities, coordinating over 2.5 million devices to manage 3.4 gigawatts of flexibility, built for the moments when utilities can't afford uncertainty. Energy Hub builds and operates virtual power plants

that utilities actually stake their grid planning on, coordinating EVs, batteries, thermostats, and more through a single platform built for utility scale. Predictive, verifiable, and designed to perform when it counts. Learn more at Energy Hub, Trillions of dollars are flowing into clean and critical infrastructure, but those investments aren't driven by technology alone. They're shaped by markets, by policy, by capital, and by the institutions that connect them. I'm Alfred Johnson, CEO of Crux, and host of a brand new podcast,

Critical Capital. Each episode, I talk with people deploying capital, shaping policy and building the clean economy. Tune in as we unpack how progress is actually made. Listen to Critical Capital on Spotify, Apple, or wherever you get your podcasts. I'm Shale Khan. I'm a partner with the venture capital firm Energy Impact Partners. Welcome. So as far as I can tell, there are basically four ways to decarbonize aviation. First, stop flying so much.

I don't want to get into that one, but let's just say I don't think it's going to be enough on its own. Second, don't decarbonize aviation directly, but offset its impact with carbon credits or carbon removals or something like that. Same story for me. It might play a role, but not a full solution. Third is what's actually mostly happening today, or at least getting announced today, and that is switched to sustainable aviation fuel, either bio-based fuel or potentially synthetic

fuels made from captured CO2 and hydrogen. Lots to talk about there, but for today, let's focus on the fourth category, which is zero emissions aircraft. This is planes powered by something other than a drop-in jet fuel, maybe electricity, maybe hydrogen, maybe a hydrogen carrier. This is certainly the most disruptive of the four groups when you think about what it means for aircraft design, airport infrastructure, regulatory and certification, et cetera, et cetera. And there are a series of big technology questions, particularly around which segments of aviation, if any, these technologies would best address. So let's get into it.

My guest is Giant Mukapadia, who conducts aviation research at the International Council on Clean Transport. Also, I will note, he has a PhD from Stanford and aeronautics and astronautics, where his research focused on, quote, developing a virtual flight testing framework that utilized multi-fidelity information sources and quantify the uncertainties and simulation predictions. Like you, I have no idea what that means, but it sounds cool. Here's Giant. Giant, welcome to Catalyst. Thanks for having me, Phil. It's great to have you here to take to the skies and talk about zero emissions aircraft. So I think we'll divide this conversation into by technology, sort of.

So we'll talk about electric aircraft and we'll talk about hydrogen-powered aircraft and we'll see where we land at the tail end of that. This is a lot of flight metaphors that I don't mean to be using. Okay, let's start with electric aircraft. Where are we? Like, what's getting developed right now? What are we seeing in the works as far as pure battery electric aviation? So in terms of battery electric aviation, we have about two or three companies that are really on the forefront of this.

And they're developing different sizes of aircraft. So the first is aviation, which is developing the Alice, that's the name of their aircraft. And it's a nine-seater airplane that they say can travel about 850 nautical miles without accounting. for reserves. Slightly bigger than that is Hart Aerospace, which is a 19-seater aircraft, and they're claiming 400 kilometers, including reserves. And then at the highest level, there is right electric, and they're trying to build a 100-seater aircraft, but they're also developing newer battery technology, so it's unclear what kind of ranges they're expecting to see with those. And you mentioned the ranges for each of those.

Obviously, a nine-seater plane, you know, a current nine-seater plane probably operates a totally different duty cycle from a 19-seater, obviously from 100-seater. Are those ranges in line with what you would expect to see for an aircraft of that size based on how we use those types of aircraft today? Or is that, you know, is it less than how we typically use them today? obviously also depends on the routes, the recharge times, all this kind of stuff, but just orient us there. Yeah, so we're actually, so we recently did a study on these electric aircraft, and we found that those ranges were a little on the optimistic side of what can be expected. With current battery technology and including sort of the standard reserves that are required for flights, you would probably get about 150 kilometers out of the nine-seater aircraft, which is a lot less.

That's close to 100 miles, at which point, if you can, you should just drive. So it is quite short and really only useful for things like island hopping or places where basically geography becomes a limiting factor in terms of trains or cars. So thinking of Norway, for example, where fjords cut into the way of roads. And so driving is not possible. And you really do have to take those really short hop flights. In general, these are much shorter than what current aircraft of that size would be able to do. They often can go much further in the 1,000 kilometer range.

So that's about 600 miles. sorry, 600 miles. And so these are significantly shorter than what fossil-fueled aircraft can do, but they would be also a lot more efficient, up to two and a half to three times more efficient than fossil-fueled aircraft on just like a pure energy basis. So obviously the limiting factor for range is, as you said, this is sort of assuming current battery technology. So my experience with companies that are pursuing electric aviation of one kind or another, they're generally not assuming current battery technology. Some of them will say our initial aircraft doesn't rely on a battery breakthrough or something like that, but in the long term, most of them are assuming that batteries become a lot more energy dense. So when you're saying sort of the existing expectations are a little bit ambitious, that assumes sort of static battery energy density and how much.

how much of a breakthrough do we need versus incremental improvement to get to the types of ranges that you would see out of traditional aircraft today? Out of traditional aircrafts probably significantly larger, but the fact of the matter is traditional aircraft are generally overbuilt. They're designed for ranges that are much longer than what are actually used. So when you're talking about actual usage, and you're talking about turboprop aircraft. So these are the ones with the propellers that you can see spinning around. Most of the flights are under 750 kilometers, and the median flight distance is about 400 kilometers.

And to get to those ranges, you still need approximately a doubling of battery storage densities. So if you're talking about sort of the Tesla Model 3, like state-of-the-art battery technology, that you can get about 250 watt hours per kilogram of battery. You would need to get to about 500 watt hours per kilogram to really make those ranges viable for most of these aircraft, regardless of size. Whether you're talking about 9, 19, or 100-seat aircraft,

you require at least a doubling of current battery technology. And that's really a significant increase, especially when you're thinking about just lithium-ion. batteries. That is close to sort of the theoretical limit of what is possible when you start packing cells into a pack and start taking into account sort of the thermal cooling requirements that would be associated with the size of batteries that these aircraft require. So yeah, I think getting to 500 is a challenge for sure. That is, I would define that as a breakthrough. So do you think there's a realistic path to market wherein these electric aircraft companies start with

shorter range aircraft that maybe don't meet the existing duty cycles of most aircraft of that size, but there's enough of market there for the puddle jumpers or as you've called them fjord jumpers to get into the market that way, and then they slowly ride the, or quickly ride the battery energy density curve upward into longer and longer range aircraft over time. There is actually a significant market for that because airlines have in the past few decades shut off shorter routes because these really small commuter aircraft were really uneconomical and inefficient to operate. And so the operating costs got so large that the ticket prices became unaffordable.

With these smaller electric aircraft, you have a much lower operating cost. And so the economics of these shorter routes actually starts making sense again. And that is why you might be able to have these small airplanes enter at much lower ranges. But as you end up, as these battery technologies improve, you can replace the battery and get longer ranges on the same airframe, which is kind of an interesting concept. And something that is being suggested by hard aerospace and aviation and the last. like. And what is the timeline that we're talking about here? Like when one of these companies saying that they're going to be in market, what is the pathway to getting to market from a regulatory perspective, an infrastructure perspective, and so on? Like when when we might we see these in operation?

That is the million dollar question. Currently, there is one certified electric aircraft. And that one is the pipistril Velas electro. It's just a two-seater and it can fly for about 40 minutes. and it's more of a training aircraft. But when you were talking about commercial aircraft that has a whole another set of sort of certifications that are required, these companies are saying about 2024 for entry into market, I am guessing it's probably going to be more like 2026 by the time they're actually able to deliver aircraft on a regular basis to customers. Got it.

And what about from an infrastructure perspective? How difficult is it, obviously, you need charging infrastructure at the airport. Maybe you need more power to the airport. I don't know. How big a challenge is that relative to the challenge of just making an airplane and getting it certified? So I don't really think that the charging infrastructure is that much of a problem. Yes, it is a bit of an investment from the airport side. You would have to start bringing in pretty high capacity chargers for these aircraft.

these aircraft require batteries on the size of 700 kilowatt hours. That's about 10 times the size of the current sort of Tesla standard. And so for that, you do require big chargers and higher megawatt as a kilowatt hour or megawatt chargers, but that's not necessarily like a technological barrier, more of just a money thing. And I think the economics of the electric aircraft and sort of the energy. energy efficiency gains that you see when you use electricity instead of regular jet fuel for these aircraft would justify that investment. And I don't really think that's going to be a significant

problem. And the other thing is, if you do start getting these charges in airports, there are other parts of the ground operations that can be electrified. So, for example, like an aircraft right now, when it's taxiing, is using its massive aircraft engine at very low throttle. to really move this aircraft on the ground. It's extremely inefficient. So, for example, that could be turned into an electric tow truck that moves the aircraft around the airport, gets it to the runway, and then you can spool up the engine and get ready for takeoff. And so there's the small efficiency and sort of energy improvements that can be, that come along with developing the electricity infrastructure at airports.

overall, what impact do you think that electric aviation might have on the overall aviation market, on emissions from aviation? Like, how big a deal are we talking about here potentially and when? So this is a bit of a bummer in this whole story, is these electric aircraft, in the end, don't actually end up playing a significant role in terms of the global aviation market. We're talking about close to like 0.1% of the global aviation traffic can be serviced by these aircraft. Now, that's in terms of sort of passenger kilometers. If you're talking about actual departures, that's more in the range of 2% to 5% of total departures that can be addressed by these electric aircraft.

And sort of that difference in passenger kilometers and departures is because when you have these really short flights, you have them serviced multiple times in a day. So that's more departures, but a fewer passenger kilometers. So it does end up having a greater impact in the departure space than in the overall aviation space. But there are other technologies

that can address a little more of the traffic question. So we'll get to other technologies. But I guess the other thing I realize that makes me wonder is to what extent is charge time an issue if we're trying to operate these planes for multiple runs a day is and we're going to try to put as big a battery pack in as we can do we need super fast charging are the you know current batteries capable of that is the electric load at the airport capable of that or is that just not an issue so the when you're talking about sort of megawatt class of charges then it doesn't end up becoming a

problem because these aircraft can then be charged in usually in less than an hour. The other thing is when you're taking into account the reserves that are required for flight, these batteries don't get discharged all the way. They get discharged at maximum about 70%. So you have a significant amount of charge that's already left. So those charge times aren't necessarily going to be a problem. Again, these are, in terms of battery technology, the weight is still really the most limiting factor. Charging, faster charging.

Those are technologies that are developing and maturing much faster than the weight of the batteries are reducing. Okay, so let's move on from Pure Electric then and talk about another zero emissions aircraft trend that we've been starting to see, which is hydrogen powered aircraft. So there's two categories here. that we should talk about separately. There is using hydrogen in a fuel cell to power the aircraft, and then there's combusting hydrogen directly. Can you just talk at the high level about the trade-offs between those two? Yeah.

So when you're talking about fuel cells, these are more efficient than when you're combusting hydrogen, you're using chemistry to convert that hydrogen into water and get electricity out of it. The other advantage of using fuel cells is that it is really zero emission. Like the only emission is water vapor, which yes, is a greenhouse gas and can cause warming, but at the sort of altitudes that these aircraft would operate at, that is less of a concern. When you're combusting hydrogen, however, you get water vapor, but you also get nitrous oxides, the NOx emissions from the combustion process itself. So it isn't necessarily zero emission. But on the flip side, when you have a gas turbine that is powered by hydrogen, that can provide a lot higher power than

a fuel cell can. Fuel cells right now are in the range of 200, 300 kilowatts. Whereas when you're talking about the power required to run a single aisle aircraft like the A320, we're talking in the megawatts, in tens of megawatts, 20, 30 megawatts required for that to generate the thrust to be able to fly that aircraft. So fuel cells are significantly smaller in terms of power output than combustion, and that's really where the advantage of hydrogen combustion lies. Virtual power plants are becoming a reliable way for utilities to manage capacity, but enrolling devices is just the start. What really matters is confidence, knowing those resources will perform when dispatched, and being able to prove it,

from the control room to the living room. Energy Hub's platform handles the full picture, from near-real-time forecasting, locational dispatch, and the kind of rigorous verification that holds up when regulators, grid operators, or leadership, ask, Did it deliver? Easy enrollment creates momentum. Proven performance builds trust. That's why more than 170 utilities rely on Energy Hub to manage over 2.5 million devices delivering 3.4 gigawatts of flexible capacity. See what that looks like at energyhub.com. We're living through a profound economic shift, and energy sits at the center of all of it. Trillions of dollars are flowing into power plants, transmission lines, battery factories, data centers, but the future of energy isn't shaped by technology alone. It's shaped by markets, by policy, by capital, and by the institutions that connect them. I'm Alfred Johnson, CEO of Crux,

the capital platform for the clean economy. Join me for my brand new show, Critical Capital, as I talk with people deploying capital, shaping policy and building projects. Together, we unpack how risk is priced, how incentives are structured, and how progress is actually made. Listen to critical capital on Spotify, Apple, or wherever you get your podcasts. So to the extent that we see activity and hydrogen aircraft development, what's the balance right now between fuel cell and combustion? So again, because of these differences in the amount of power that can be provided by different propulsion technologies, the fuel cell aircraft is sort of limited to smaller

turboprop engines that can carry at most probably 60 or 70 passengers. And when you're using gaseous hydrogen, you're getting ranges about 600 kilometers. Whereas if you're talking about liquid hydrogen combustion, which is on the other end of that, you can fly like 168 passengers almost 200 miles or 3,400 kilometers. These are significantly larger ranges that can be expected from hydrogen combustion, just because you can produce a lot higher power in a gas turbine engine than in a fuel cell. And correspondingly, these companies are, there's different people that are working on these aircraft. On the fuel cell side, you have smaller startups that are working on that, like

Zero Avia or Universal Hydrogen. These are companies that are able to be viable because the capital investment required for developing a smaller aircraft of like the 60 to 70 passenger size is a lot less compared to the capital investment required to build an A320 sized aircraft. Now, these are, on that scale, there are only Airbus and Boeing that operate. It is essentially a doopoly when you're talking about flights, aircraft that can carry more than 150 passengers. And you do see out of those two, Airbus is the one that is developing, or at least has plans to develop a hydrogen aircraft of that size. And it's called the Zero E program. They're currently trying to test out

a hydrogen-powered gas turbine. Interestingly, they're trying to put it on the A380, which is like the biggest aircraft that they have. They're trying to test the hydrogen combustion engine in conjunction with the other four engines and see what the emissions and contrial formation and things like that that come out of that engine are. So that is on the high end of the passenger and range

capacity, whereas fuel cells, again, stay towards the lower end with still really only replacing turboprop engines, like, or aircraft kind of like the ATR 72 or the dash 8. These are sort of aircrafts you'll see servicing generally like smaller hub to a bigger hub kind of routes. So the thing with hydrogen is that it's very light, but it takes up a lot of space. Right? So typically, as you think about something like aviation, like the trade-off is, yeah, you don't have the weight problem that batteries present. Batteries are very heavy. On the other hand, you need a lot of space to store sufficient hydrogen to power an aircraft of any size, but particularly true for these larger aircraft. So for those who are designing these hydrogen-powered aircraft, how are they dealing with the space issue?

Yes, the space issue is significant, especially because aircraft are also constrained. both in mass and volume. And if you've traveled economy on a budget airline, you know you have to fit into ever-narrowing rows of seats and have to pay for every ounce of baggage that you bring on. So that requirement for the fuel being extremely energy dense, both in mass and volume, is extremely pronounced in aviation. Hydrogen has really high energy per unit mass, but has a lot of has really low energy per unit volume. So when you're talking about hydrogen, you can either store it and compress tanks, but really you need to get to liquid hydrogen to be able to get these longer ranges out of these aircraft,

to really be able to fit enough hydrogen into the aircraft. What ends up happening is you end up sacrificing seats. You end up sacrificing payload capacity or passenger capacity to be. able to carry some of that extra hydrogen, which isn't the worst because you can, even when you take into account the volume requirement of liquid hydrogen, you can still service 160 passengers traveling 3,400 kilometers. That is, at least, that is two-thirds of all narrow-body flights, or about a third of all commercial aviation. Liquid hydrogen aircraft can replace one-third of all passenger aviation that is flown currently. And that is a significant chunk

and that is really worth pursuing in that sense. So where are we in the development of these hydrogen-powered aircraft? What's the timeline expectation around the development here? And I guess as an addendum to that question, for fuel cell powered aircraft, given that you're saying that the best fit for those are sort of in the smaller range, that's where there may be actually some competition between, you know, the sort of higher end of the electric aircraft and the lower end of the hydrogen aircraft potentially serving some of the same use cases, right? Yeah, that's exactly right. And to get to, for electric aircraft to get to sort of the fuel cell ranges, you do need those batteries to get better. So for the time being, those fuel cell

aircraft will operate in a space that is free of competition from the electric aircraft. but these fuel cell aircraft are sort of closer to market than the liquid hydrogen combustion aircraft but are slightly further away than the electric aircraft. So for example, for electric aircraft, I said 2026 is about when you'd expect commercial deliveries of those aircraft. For fuel cell aircraft, you could probably expect them 2028, 2030. That's because these fuel cell technologies, and sort of the gaseous compressed gaseous hydrogen storage has been proven in automotives

with those fuel cell aircraft like the fuel cell cars like the Toyota Mirai. When you're talking about hydrogen combustion, that is a completely new technology. Like no such engine exists and flies currently. So it requires a lot more development to get that to market. And those aircraft are likely only to show. show up in the market in about 2035. And that's the goal that Airbus has set for itself. And when you're talking about that timeline from now to 2035, that gives them about three or four years to develop and mature the technologies. It gives them about two or three years of

putting the supply chains and the manufacturing in place to be able to mass produce an aircraft of that size. And then it takes about seven to eight years to actually build those aircraft and start delivering them consistently. And so with that timeline, yes, 2035 is probably the earliest I would expect a liquid hydrogen combustion aircraft to show up. And then there is also the fact that aircraft have really long lifespans. These, there are aircraft that are flying to date, that were built in the 1990s. So with that in mind, the fleet turnover then becomes another sort of barrier for these hydrogen aircraft to make an impact.

You need airlines to start retiring older aircraft and buying these new hydrogen aircraft. And so our projections suggest that even though hydrogen aircraft could service a third of passenger aviation, the actual market penetration is probably going to be more like 6 to 12% by 2050 because of that slow fleet turnover rate. And I guess similar question on the hydrogen side to what I asked on the electric side, which is infrastructure requirement. I mean, here there's more, right? Because in the context of an electric aircraft, you really just need a charger, you've already got electrical hookup. obviously, maybe you need to increase your power capacity, but that's not a total overhaul of

refueling infrastructure. Hydrogen would be a different story here. Am I wrong? No, you're absolutely right. Hydrogen production, delivery, storage, refueling. All of these are challenges that will need to be addressed. Specifically, the hydrogen production and delivery is really massive, and this is where the drop-in sustainable aviation fuels become more attractive. Because those can be produced and sort of use the infrastructure that is already in place for jet fuel, hydrogen would require you to build completely new plants. You would need to have, if you're using cryogenic, sorry, liquid hydrogen, you would require cryogenic storage solutions.

And really the best option, for all of this is to be able to produce and store that hydrogen on site. So the airport itself would have the means to produce that hydrogen and store it and then use it as quickly as possible because hydrogen storage is also expensive. When you're talking about liquid hydrogen, again, you start having, there is heat that will creep into the system and boil that liquid hydrogen off into gaseous hydrogen, and then you have to reliquify it. And so that cycle becomes pretty expensive and energy intensive. So in an ideal scenario, an airport is able to have all of that hydrogen produced on site and used as soon as possible. And the estimates for about, for what kind of

investment that would require is on the order of sort of build all of that on-site production and storage, it would cost as much for the airport to build a whole new terminal. Like that's kind of the sort of scale of investment that is required. And that's significant, but airports build new terminals fairly often, especially in this day and age of rapidly increasing, rapidly growing aviation market. So it's not, it's not unfathomable, but it is an investment that is required. And I guess that gets to, you know, this conversation is about zero emissions aircraft. So we're not talking so much about sustainable aviation fuel and drop-in fuels, whether they're bio-based or electrofuels. But in this context,

I guess I want to ask stepping back, looking at the progression of development of both electric aviation and hydrogen-powered aviation, and then comparing against the world of sustainable aviation fuel, which has its own challenges that we won't get into now, but has the benefit of not requiring all this infrastructure turnover. What is your prognosis for how we may end up balancing these, I guess, three different big categories of aviation decarbonization? That's a great question, actually. So the way I like to introduce all of these decarbonization pathways for aviation is them sort of taking different niches of the aviation market. So electric aviation service is really just the smallest aircraft, the shortest routes.

Hydrogen aviation can do short haul and a little bit of the medium haul, sort of the single aisle aircraft market can be replaced by hydrogen. And then sustainable aviation fuels would play the biggest role in the longest flights. So when you're talking about long haul flights, flights greater than 4,000 kilometers, intercontinental flights, flights that go over oceans, those are the kinds of flights

that sustainable aviation fuel would have to play a part in. And my view, and I think a lot of people hold this, is we kind of have to do everything. there is going to be a shortage of each of these fuels. Sustainable aviation fuel is really hard to make. Hydrogen is in fact a precursor to especially the synthetic sustainable aviation fuels. So instead of using the hydrogen, combining it with captured carbon to make the synthetic fuels,

if you can use the hydrogen directly, by all means, use that hydrogen. directly, it will be more energy efficient to do so. And then on the lower end, electrify everything. As much can be electrified, should be electrified. Wherever hydrogen can be used, should be used, and everything else will require SAF to decarbonize. And that's really the only way we get to net zero emissions by 2050. Taking another big step back and looking at the overall climate impact of aviation, As I understand it, there's actually a fairly significant portion of the aviation impact on global warming that comes from contrails as opposed to from greenhouse gas emissions directly from aircraft. How do you think about that in the context of the development of fuel switching, of new aircraft? Is there a completely other category of things that we need to do to mitigate contrails?

So contrail avoidance is of barrow mounted. importance as well because they say that current research suggests that the impact, the non-CO2 impacts, which includes these contrail formation, can be twice as much as the impact from CO2 alone. And so trying to avoid these non-CO2 impacts is super important. The good thing about using synthetic aviation fuels is that automatically addresses some of that contrial impact because the contrials form because of incomplete combustion because of aromatic compounds that are in jet fuel. When you're creating pure synthetic aviation fuel, you don't have that aromatic compounds and so the contrial formation reduces automatically.

With hydrogen, it is the jury still out. These engines don't really exist so you can't really tell whether those contrail formation is going to be higher because one of the outputs is water vapor or whether it's going to be lower because there is no suit that is formed when you combust hydrogen. So that's kind of a very active area of research and kind of a question that Airbus is trying to answer by putting a hydrogen combustion engine on an A380 and testing both engines in the same environmental conditions and comparing emissions. In electricity, the best part is you don't have any emissions at all. You don't have even the water vapor. It is just electricity that's being converted into thrust by those motors. And so that's the holy grail, zero emissions, no environmental impact

except to produce the batteries. And to produce the electricity that powers the batteries. Yeah, exactly. But either way, substantially. better than any alternative if you could do it. Yeah. So that's actually an interesting point, because when you're talking about the electricity used to produce the hydrogen, for example, or the synthetic aviation fuels, even producing those fuels is less than 50% efficiency. So you lose half the energy that you put in just to produce these fuels. So automatically, electric aircraft are twice as efficient. And then when you take into account the electric propulsion efficiencies, you can get close to six to seven times more efficiency between electric aircraft and jet aircraft

that are run on synthetic aviation fuels. And so that's enormous because when you, if you try and run the entire aviation industry on electricity, right, in 2050, the amount of electricity that would be required to decarbonize aviation is the entire renewable energy production today. So all of the renewable energy that is produced today could be used up in aviation alone. So that sort of gives you really the scale of the energy demand that would be required from aviation. And it's not just the aviation sector that's trying to electrify. It is all these other sectors that are trying to electrify and reduce. their carbon impact. So just the pure demand of electricity in the next few decades is going to

balloon. And decarbonizing the grid also needs to take into account that increase in energy demand. Yeah, I mean, I agree. This is one of the most underappreciated things about lots of different decarbonization plans, which is so many of them rely upon load growth and electricity. Aviation being one major category amongst a bunch. I mean, take things like direct air capture, take heating electrification, all sorts of things. Like every one of them stacks on top of each other. And supercharges are a need to decarbonize but also expand the grid simultaneously, which is a challenge in and of itself and a topic for another day.

So in the meantime, Giant, thank you so much. This was super illuminating for me. Yeah. Thank you. Giant Mukapadia is an aviation researcher at the International Council on Clean Transatlantic. transportation. What did you think? As always, we welcome your feedback.

Let us know. Find the show on Twitter at At CatalystPod. You can also find me there. If you like the show today, as always, go over to Spotify or Apple Podcasts and leave us a rating and review. We do appreciate that. This show is a co-production of PostScript Media and Canary Media. You can head over to canarymedia.com for links to reports about zero emissions aviation

that Giant and his team at ICCT have put together. And as always, PostScript is supported by Prelude Ventures, a venture capital firm that partners with entrepreneurs to address climate change across a range of sectors, including advanced energy, food and agriculture, transportation and logistics, advanced materials of manufacturing, and advanced computing. This episode was produced by Daniel Waldorf and Dalvin Abuaji, mixing by Greg Wilfrank and Sean Marquand, theme song by Sean Marquand. Our managing producer is Cecily Meza-Martinez.

I'm Shail Khan, and this is Catalyst.