Leeham News and Analysis
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Leeham News and Analysis
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- Boeing 2024 Proxy Statement: Executive Compensation includes retirement gifts for Calhoun, Deal; housing support for Ortberg, Pope, and other stuff March 17, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 13. March 14, 2025
Bjorn’s Corner: Air Transport’s route to 2050. Part 9.
By Bjorn Fehrm
February 14, 2025, ©. Leeham News: We do a Corner series about the state of developments to replace or improve hydrocarbon propulsion concepts for Air Transport. We try to understand why the development has been slow.
We have covered the progress of battery-based aircraft and hybrids. Last Corner started looking at hydrogen-fueled alternatives. A day after the Corner, the Airbus workers union Force Ovrier published information from an Airbus internal meeting, in which the airframer delayed the introduction of a hydrogen aircraft by 2035 to about 10 years later. As a consequence, it reduces the R&D spending on the development of hydrogen propulsion technologies.
Figure 1. The Airbus ZEROe concepts. Source: Airbus.
The Hydrogen Echo System
The reason given at the internal meeting was that the supply ecosystem of green hydrogen is developing slower than anticipated, including the hydrogen production, distribution, and availability at relevant airports.
Since the start of the Airbus ZEROe hydrogen-focused alternative propulsion project (Figure 1), it’s been clear that the air transport market cannot lead the transition to hydrogen. The volumes are too small, just as they are for the development of aircraft battery technology.
The development of the key elements of batteries and hydrogen for transport applications has to be led by the huge ground transport market, the air transport market is too small.
Figure 2. The Mercedes liquid hydrogen fuel cell truck runs 1,000km on one tank. Source: Mercedes Truck.
The project that would lead the transition to liquid hydrogen for transport applications would be the long-haul truck industry, Figure 2. The truck industry has converged on battery-electric trucks for local distribution, where these can be charged overnight and then deliver goods during the day.
Also, some longer-haul trucking, such as trucking between urban areas, can be battery-electric if the fast-charging infrastructure is available. But real long-haul truck transport can’t function with the need to charge 30 minutes or more several times daily.
This is where the largest truck supplier, Mercedes, has developed liquid hydrogen fuel-cell electric trucks and tested them on long routes over the last years. Figure 2 shows a test run from 18 months ago, in which a fully loaded 40-tonne Mercedes truck was charged with 80 kg of liquid hydrogen at Woerth in Germany and then ran the 12-hour Autoban trip to Berlin, 1,000 kilometers (620 miles) away, without refueling.
The transition from diesel trucks to battery or hydrogen trucks has just started (it trails the change to battery-electric cars). This change has to happen before the investment in the production and distribution of hydrogen for air transport can happen.
Only then can air transport latch on. So it’s not a matter of air transport not wanting to change; it can’t change unless the much larger and more important change in ground transport happens.
The same stark reality is true about the aircraft battery system. Aircraft startups that have bet on battery-electric concepts have universally found that their capacity doesn’t allow a sensible design of a short-haul aircraft or anything but an ultra-short-haul eVTOL flying the 10-minute mission from an airport to a city center.
Those who promised too much had to bet on special battery chemistries (Lilium is one), which has consumed a vast amount of R&D money for the energy store. As predicted, these projects are running out of money as we speak (Lulium is not out of insolvency, CityAirbus is frozen because of batteries, and eViation is going into hibernation…).
When the craze started around hydrocarbon propulsion alternatives some eight to 10 years ago, we published this Gartner Hype Cycle curve, which describes the typical cycle around new technology advancements.
Figure 2. The Gartner hype cycle curve with a year-scale added by me. Source: Gartner Inc.
This is the Gartner hype curve of the Corner from April 10, 2020, where I daringly put years underneath the curve. The recent announcements of the demise of several alternative propulsion projects, where we said five years ago this would happen, are pretty spot on.
So, we have now passed the “Peak of Inflated Expectations” and are on our way down the “Through of Disillusionment.” Are we at the bottom? Most likely not. We will be there in 2026 or 2027 when the first operational eVTOLs start flying and the naive business cases go up in smoke. That is the negative part.
It is essential to understand that once we get past this, around 2030, we will see real progress and viable alternative propulsion solutions with a useful range for battery electric aircraft and eVTOLs and the emergence of functional hydrogen supply for the longer-range hydrogen solutions.
The subject of the Corner changed
We should have started covering the hydrogen burn solution this week, but given the development since the autumn and especially the Airbus news from last week, a pause was needed to put it all in perspective.
We have been critical of overinflated expectations for 10 years now. However, this doesn’t mean we don’t believe in a change to more environmentally friendly propulsion solutions.
It’s just, you have to put pen to paper and check all the wild statements that have been circulated. We didn’t even have to employ our sophisticated Aircraft Performance and Cost Model (APCM) to punctuate these claims. A simple check using first principles sufficed.
Next week, we continue with hydrogen burn.
Hello Bjorn, good post. When you start covering hydrogen burn in more detail, I think it would help to compare the cost of Green Hydrogen vs. Jetfuel for the same amount of energy. The higher cost is one of the challenges for widespread adoption in the traditionally low-margin airline industry.
A very valid point.
However, for the sake of completeness, a third cost should be added, i.e. that of jetfuel plus the expense of capturing and storing the CO2 and NOx that it produces.
Scania trucks made an interesting presentation regarding heavy trucks and batteries: “For a long-haulage operation in Europe, the speed and driver rest regulations mean you’ll never drive more than 360 km in a single stint (4.5 hours of driving, at 85 km/h maximum speed). And the driver rest period is of course always the most optimal time to charge your truck away from the depot no matter your maximum range”. Already today they offer heavy electrical trucks with +700 kAhr battery packs and most applications require less than 500 kAhr. Still you need access to truck fast chargers.
Yes. Imagine the truck charging pileups during cold winter days when the range is down 30%, and everyone must charge more often. We now have these nightmare scenarios with battery cars during the northern European ski holidays. Cars waited in a charging que up to four hours in minus degrees to be charged for them to be able to drive to their destination. The problem is you block the facility for at least 1/2 hour, if not more for trucks. There is very little change in the flow to the station for it to be a queuing problem. Filling diesel or LH2 is two to three minutes.
Here is another solution for charging:
https://www.hessenschau.de/wirtschaft/ehighway-110~_t-1736431861165_v-16to9.jpg
https://www.hessenschau.de/wirtschaft/e-highway-auf-a5-bei-frankfurt-abgeschaltet-v1,e-highway-abgeschaltet-100.html
For big trucks there is enough room to insulate the batteries so they won’t freeze in wintertime.
I still would prefer Methanol over LH2. There are even fuel cells operating with Methanol: DMFCs. Far easier to handle than LH2.
Hi Bjorn,
A question in relation to the charging queue problem.
Why are replacement batteries not a thing? ie: slide out a 500 kAhr battery pack onto a trolley and replace it with a fully charged battery(s) and 5/10 min later you are on your way?
Is there a fundamental reason why this is not a thing? (For aircraft / trucks / cars etc) No more queuing and the discharged battery gets recharged for another vehicle tonight / tomorrow?
I don’t know. The fact is, it has been talked about for 10 years and never, to my knowledge, implemented in real operations.
It might be the risk of theft. A battery pack of 500kWhr is worth around $100k if it’s a truck battery and $1m if it’s an aeronautical battery in the market up to 2030. It would be a high risk of these batteries getting feet if they were easy to take off and transport.
Tesla even demoed an automated battery swapping system that would swap batteries in under 2 minutes.
couple problems: would require standardized battery sizes and interfaces across car brands, “gas station” would have to invest in batteries to hold in inventory to swap, owners of a car with a failing battery could swap and leave the charging station hanging with a broken battery, other issues I’m sure I haven’t thought of..
This technology is already well-established in China, where numerous local truck manufacturers offer electric trucks with replaceable batteries. These vehicles have gained significant popularity due to the substantially lower cost of electricity compared to diesel.
Electrical Truck charging is gaining power and has passed 500kW on top model chargers so time at those chargers are reduced, the development migh see 1 MW chargers soon, still the number of trucks is less than electrical cars and often charge at terminals where the semitrailer can change tractor if needed. Germany is betting on a national hydrogen network for trucks (that might be an overkill) so their airports can be the biggest users of green hydrogen if range boosting fuel cells becomes popular.
Fast charging radically reduces battery life.
This is yet another problem for the secondhand market,I’m not aware of anyone recording what the battery has gone through with the previous owners.
If you have a company car or change every 3 years or so you will prioritise convenience and speed
Trucks, both heavy over the road, and local delivery/local business are probably one of the best targets for electrification.
the current heavy truck fleet is largely high polluting diesels (especially in the US with our industry of dropping old engines into new “glider” chassis), the driver rest regulations mandate fairly long stops every 4 hours (unless team driving) and the vast majority of miles driven on major highways or point to point inter warehouse, so ensuring the charging infrastructure is in place should be easier.
additionally these trucks have a lot of weight margin, the existing drivetrains and high volume fuel tanks are very heavy and swapping that out for an electrical battery/motor package is largely within the weight margins.
for local delivery/local service company work, the total # of miles a day is almost always under 200 and the trucks can charge overnight in the motor pool
The Daimler truck in the story had a 70kWhr battery – re charged from braking and ‘excess fuel cell power’. As it needs help on steeper hills.
The LH2 came from a methane to hydrogen facility- but window dressed to be ‘bio-methane’ for the journey
“The development of the key elements of batteries and hydrogen for transport applications has to be led by the huge ground transport market, the air transport market is too small.”
And yet an airport would need to store hundreds of tonnes of liquid hydrogen, and find a way of getting it into (and out of?) the aircraft.
I can see that this is a problem in infrastructure terms, however I don’t see that the trucking industry is going to make it any easier by going first. Road traffic useage and storage requirements would be significantly smaller I’d think.
In fact the reverse, if we had facilities producing hundreds of tonnes of LH2 for airport use, it would be easier for the road haulage industry to start diverting some output to road-side refuelling stations is comparatively small quantities, for storage in many more much smaller tanks.
Likewise fuel cells. A fuel cell for a truck will be much smaller than an aircraft fuel cell. Even if the technology is scaleable, mass production of units for trucks won’t make cells for aircraft easier or cheaper to obtain as they’ll be completely different in size.
There are ideas for medium size fuel cell as just a range extender for battery powered aircrafts/AAM’s or as APU’s on mainline aircrafts. Many times APU’s are used for limited electrical power for taxi and to heat the cabin before boarding in cold climates. The fuel cell can be used for both power and heat as well as filling fresh water in different systems.
I remember years ago two highly qualified Airbus engineers were invited by a EU commision to present their insights on sustainable aviation directions.
They made a mistake by presenting the blunt truth as they saw it, including graphs, trends etc.
There was surprize and it took a few days for Airbus PR to nuance everything and guide everyone back into a hopefull thoughtstream, full of opportunity.
Because that was what everybody (politics, industry, environmentalist, public) wanted to hear.
+1
+2
100%
This is unfortunately the world we live in.
I am amazed that you really think we will get to working eVTOLs that meet their advertised range and payload.
If you actually believe your own numbers and work, you’ll be forced to conclude that ALL eVTOL will fail, because the batteries are not there, and probably never will be.
Which means eVTOL follows fuel-cell-powered cars into oblivion.
I think for serious apllication of eVTOL like vehicles, you would have to look for tech meeting operational requirements. Not for requirements meeting the tech limitations (“solution looking for a problem”).
If such operational requirements are e.g. 1000km range, fast, safe, quiet and agile, maybe e.g. a micro turbine making sure batteries never get below 40% empty could work.
Niche applications for police, ambulance, defense could become viable if its more affordable, pratical than a helicopter..
I think the whole approach is wrong.
Propane and Natural gas are not perfect, but they are far better than coal an even diesel.
Diesel trucks like gasoline cares are more and more shifted to clean. The few re-engines are not an issue.
Treat it like a system, not trying to pick a bit here and there. So get rid of coal to start with. Clean diesels or natural gas/propane. All within tech to do and huge drop.
Hydrogen does no good if it comes from the same polluting sources as electrical does.
Do the research but don’t insist on a single solution. Its probably going to be multiples.
Hydrogen in an aircraft is never going to meet the cost requirements (unless we just give up air travel and good luck with that).
High speed rail is a good answer for some areas.
And no I am not against working on better. We have an electric lawnmower that is the perfect answer for that application (it works as good as a gas, there is no gas, there is no oil, maint is zero).
But we don’t need V Tol Taxi, it does nothing efficiency wise you can’t do over a smart phone, cost is huge for traffic control and its for well off people, not normal people.
You want those things buzzing up and down your streets and crashing?
Get real,it’s not going to happen or it already would have
You’ll need a lot more lorries because they will be carting huge batteries around instead of produce.This problem is hundreds of times worse for an aeroplane.
No one is serious about even the basics like suppressing demand,banning inefficient aircraft sorting out air traffic control,not pointlessly shipping potential duty free around or even making sure airliners are actually full
Yep. There are a huge number of things that can make the whole system more efficient.
Any savings is a gain.
But its all being done with no comprehensive plan. Stovepipes.
But its no hype worthy, it takes thought and work and its the next shiny thing.
I think over the years, Bjorn’s articles on sustainable aviation evolved significantly. His first series was carefully formulated, leaving no room for doubt about the weak feasibility of most concepts and technologies.
Then came the hype—dozens of new entrants, commitments from strong brands and governments, orders from major operators, and confidence voiced by industry leaders.
As momentum grew, his articles became imo more nuanced, reflecting the tension between his roots as an engineer and test pilot—committed to factual analysis—and the broader push for progress, openness to change, and enthusiasm for innovation.
To his credit, Bjorn remained steadfast in his observations and conclusions. The same cannot be said for much of the press, which largely chose to cheer along with the hopeful “milestones” and expectations that everyone wanted to believe in.
Another champion hitting the wall..
https://www.geekwire.com/2025/eviation-lays-off-employees-and-pauses-development-of-electric-powered-airplane/
The other large elephant is that generating,distributing and storing hydrogen,whilst theoretically easy,is in fact incredibly difficult.This is why we don’t have it
The autobahn route from Wurth ( on the Rhine by the French border, also a Daimler truck plant) direct to Berlin is 680 or so km ( by a number of different routes) not 1000km.
It seems they went the long long way
Interestingly they say “The hydrogen supplied by Air Liquide is of renewable origin, as it has been produced from biomethane ”
Methane … of course. The Bio-methane angle is just window dressing for the media .
The production process is based on bulk methane as thats the most economical and efficient. None of the vaunted ‘electrolysis’
In the small print is a 70 kWhr battery power for ‘temporary’ use. which provides up to 400kW. To help get up hills!
So in fact its a dual LH2 Fuel cell-battery hybrid
Mercedes Benz trucks has become Daimler trucks
Why shouldn’t they use the short way from Wörth am Rhein and drive circles around Berlin on A10 until they reached the limit?
In Germany about 4 million vehicles could be powered by biomethane .
I think the 1000km was a magic number, with a full LH2 tanks, even if it required driving via Hamburg.
Must have used 2 drivers as well because of rest periods.
The Frankfurt regional commuter train service powered by H2 fuel cells has been pulled from service
“Fundamentally unreliable’ | German authorities threaten to pull the plug on world’s second hydrogen-only rail line
The entire €500m programme could be scrapped after two years of problems with Alstom’s fuel-cell trains
https://www.hydrogeninsight.com/transport/fundamentally-unreliable-german-authorities-threaten-to-pull-the-plug-on-worlds-second-hydrogen-only-rail-line/2-1-1719331?zephr_sso_ott=VpKc4l
Eviation has shut down (ahem, looking for more money, ahem, investors)
Funny we may be further on the curve of disillusionment than was thought.