Largest Ever Hydrogen Fuel Cell Plane Takes Flight

In the automotive world, batteries are quickly becoming the energy source of the future. For heavier-duty tasks, though, they simply don’t cut the mustard. Their energy density, being a small fraction of that of liquid fuels, just can’t get the job done. In areas like these, hydrogen holds some promise as a cleaner fuel of the future.

Universal Hydrogen hopes that hydrogen will do for aviation what batteries can’t. The company has been developing flight-ready fuel cells for this exact purpose, and has begun test flights towards that very goal.

Sky Hydrogen

It’s only recently that battery technology has advanced enough to build decent, usable electric cars. Even still, just getting a few hundred miles of range out of an aerodynamic sedan typically takes over a thousand pounds of batteries. For aircraft, which are significantly more power hungry than cars, batteries simply aren’t a viable power source. Hydrogen, however, could be a viable alternative, as it has an energy density on a par with fossil fuels. It can be burned in internal combustion engines and jet engines, just like fossil fuels, generating no carbon dioxide output and a minimal but measurable amount of nitrogen oxides. Even better, it can be used to produce electrical energy with only water as a byproduct, by using a fuel cell.

Hydrogen is much comparable in energy density to fossil fuels, in both weight and volume. Batteries fare far worse by comparison. Note, however, that this comparison is of the fuel itself, and does not take into account storage infrastructure like the tanks required to maintain hydrogen at the correct temperature and pressure.

For this reason, Universal Hydrogen has been working towards its first major test of fuel cell flight. The company recently completed taxi testing in February, which helped to secure a special airworthiness certificate for its experimental De Havilland Canada Dash 8-300 test aircraft. With that in hand, it was able to pursue the first flight in a planned two-year series of tests.

Traditionally, the Dash 8-300 is a regional turboprop airliner, capable of carrying approximately 50 passengers, depending on configuration.  In this case, however, Universal Hydrogen heavily modified the plane, replacing one of its engines with an electric motor from aviation company MagniX. The motor was supplied with electricity from a megawatt-class hydrogen fuel cell, while the plane was also outfitted with two hydrogen tanks carrying a total of 30 kg of fuel.

The modified Dash 8-300 built by Universal Hydrogen. Credit: Universal Hydrogen, press site

For its first live test, the plane, nicknamed Lightning McClean, took to the skies for a fifteen minute flight. It reached an altitude of 3,500 feet above sea level. The fuel cell provided up to 800 kW of electricity during the flight, with water vapor the only output to the atmosphere. Approximately 16 kg of fuel was used in the test.

Of course, aviation is a famously conservative business, hence why the aircraft only ran a single hydrogen-powered motor at this early stage. The Dash 8’s other standard Pratt and Whitney turboprop ran during the flight. However, at one stage, the crew throttled down the turboprop to near-minimum, and the plane flew almost entirely on fuel-cell power alone. For now, the test flights are a low-stakes demo of hydrogen aviation. However, it’s important to collect data in tests like these, in order to get the hydrogen powertrains to the point that they can be certified as flight-ready components.

A Path Forward

While it’s early days yet, Universal Hydrogen has a clear plan for the future of hydrogen in aviation. Its testing doesn’t just serve to demonstrate a hydrogen-powered propulsion system, but also the company’s ideas around how it thinks hydrogen aircraft will be fueled, too.

Universal Hydrogen doesn’t plan for airports to install new hydrogen fuel tanks and refuelling infrastructure. Instead, it employs its own “hydrogen modules” on its aircraft. These standardized modules are essentially large hydrogen cartridges, which the company likens to Nespresso pods. The idea is that they can readily be managed by existing airport freight and logistics infrastructure. The modules can simply be loaded into the fuselage of a plane and hooked up onboard. The way the company sees it, this methodology means every airport around the world is automatically “hydrogen ready.”

Having the fuelling question figured out is key to Universal Hydrogen’s future goals, too. The company already has almost 250 orders from 16 customers on its books to retrofit existing aircraft with its hydrogen powertrain technology. The company expects to begin delivering on these orders, worth over $1 billion, as soon as 2025. That may be a lofty goal given that the company hasn’t yet secured wide-ranging approvals for its technology just yet. However, it’s a major show of faith from established airlines that the company’s order book is already overflowing.

Questions Remain

While the first test flight was a success, there’s still plenty of hurdles for Universal Hydrogen to overcome. The company must secure approvals from the FAA and other relevant authorities around the world for its technology. To achieve this, it must demonstrate that the hardware is up to the fastidious reliability standards expected in the aviation world.

Beyond that, it must also work on the problems surrounding hydrogen storage, transport, and production. The company’s modules are a great idea, but their current solutions will need scaling to tackle anything beyond the shortest flights. Hydrogen may be energy dense when it comes to weight, but by volume, it’s only a quarter as dense as jet fuel. This could impact negatively on payloads for hydrogen-powered planes. Production is an issue too. Running hydrogen through a fuel cell may be clean, but producing the hydrogen can be quite a dirty process in itself. Green hydrogen production methods using clean electricity are key to making it a more sustainable option than digging up more dinosaur juice.

It seems unlikely hydrogen will take off as a mainstream automotive fuel. Despite this, batteries still don’t offer a viable solution for heavy-duty applications like trucks, trains, and planes. Until something better comes along, hydrogen is likely still the best bet to clean up the emissions from these industries. It’s just going to take plenty of grunt work and engineering to make that a reality in the decade or two to come.

72 thoughts on “Largest Ever Hydrogen Fuel Cell Plane Takes Flight

  1. >Hydrogen may be energy dense when it comes to weight, but by volume, it’s only a quarter as dense as jet fuel.

    Liquid hydrogen, that is. It raises the question, how do you keep the fuel pods filled up and waiting without wasting a ton of energy for refrigeration, since liquid hydrogen can’t be contained by any practical pressure.

    1. You don’t. As all other system, you pressurize the hydrogen to 300 to 700 bar and store it in tanks, that’ll require regular and costly maintenance.

      Or, as some other actors are trying to achieve, you use Ammonia to bind the hydrogen to a N atom, so it can be stored at ambient temperature and usual pressure tank for the same Wh/L ratio as hydrogen. Then the technical achievement is to release the hydrogen only when required, using for example iron as a catalyst and a lot of heat (which can come from the hydrogen combustion itself).

      1. “As all other system, you pressurize the hydrogen to 300 to 700 bar and store it in tanks”

        As a result, there is a significant weight difference for the containers used to store hydrogen versus to store gasoline or jet fuel, both in the vehicle and in the fuel depot. This difference needs to be reflected in any realistic and meaningful graph of the energy density per unit mass.

        1. I wasn’t able to find the name after a quick DDG search but I remember seeing on NHK that a Japanese space tourism company is funding its vehicle design by running a side business in manufacturing custom wrapped carbon fibre pressure vessels for hydrogen (which is something they developed for their spacecraft since it will use hydrogen).

      1. If you could run your vehicles on hydrides it would not be so easy to remotely shut off your vehicle and you would have greater autonomy than some totalitarian types would like.

        1. What the hell are you on about? If these “totalitarian types” were intent on suppressing anyone’s autonomy, electric cars (which can be fueled using a wood-fired generator, or even a determined person on a bicycle) would not be available.

          1. Electric cars are only really available for the rich, and bicycles are not a practical means of general transportation especially over long distances.

      2. Maybe they should have skipped the hydrogen from United nuclear and just bought a radioisotope from them instead. Install a mini reactor in the aircraft and forget about refuelling for a decade or so.

      3. You need neither lithium-6 nor deuterium (as indicated in the video at 10:55) to produce hydrogen. Simply use the naturally occuring lithium. It consists of 95% 7Li and 5% 6Li which don’t have ANY difference in their ability to bind to hydrogen. Isotopes do not differ in their chemical properties.
        6Li and 7Li only differ during processes involving the atomic core that take place e.g. in a fusion bomb. The fusion with deuterium delivers 22MeV for 6Li but “only” 15MeV for 7Li.

        Just another scam by Bob Lazar. See also:

      1. That’s the myth, but because it wasn’t mixed but layered, it would hardly burn. The real reason it went off was still the electrostatic discharge that ignited some leaking gas, and the rupture quickly spread once the skin caught on fire.

        There’s an additional effect with burning gasses, when you have a cavity with small obstructions that cause turbulence, the flame front speeds up quite tremendously because of the mixing. Next you have to remember that the HIndenburg had several gas bladders inside the main skin, and ventilated space around the gas bladders where people could climb. Once the hydrogen was leaking – and it was leaking and diffusing around constantly – the flame could easily spread under the skin and suddenly erupt all over. The complex lattice work of the Hindenburg skeleton didn’t help in this respect, introducing the turbulence mentioned above.

        1. See. The common misconception is that the skin must have been burning from the outside in because the gas inside the balloon was too fuel-rich to burn, and that’s why the fact that it burned so quickly must mean the skin was extremely flammable.

          But in reality the outer skin and the gas bladders inside were separated by the steel skeleton, leaving a narrow gap where the gas could leak and flash over, so the skin catches fire from the inside out all over, almost at once.

  2. Synthetic and Biofuels hold more promise than hydrogen. They are denser and existing engines run on them. They are also carbon neutral. No new infrastructure needs to be built.

    1. Yup.

      Using fission or fusion we can co-generate what we need to keep the cars of today on the road with net zero carbon emissions. But why tackle 2 problems (green power generation and reducing carbon footprints) when we can make dozens of problems trying to race for not ready for prime-time technology. If we’re at all interested in reducing the carbon footprint synthetic fuel production must play a role.

      1. & when exactly will nuclear fusion be an economically viable, containable and controllable energy source? I’d say about the time that quantum computing becomes a reality as opposed to a snake oil salesman’s simulation running on a non-quantum computing substrate.

        1. Fusion may take many years, but we can fission right now. And the energy density in nuclear compared to anything else is immense. We should utilize Gen IV reactors ASAP if we’re serious about controlling atmospheric gasses to mitigate climate change.

          Nothing else will work fast enough or have enough of a long term impact.

      1. Who’s they? Fission plants? The sizes have come down considerably and the micro-reactors being discussed can be implemented. Solar and wind take plenty of land too, and not nearly as energy dense as nuclear, not even close.

  3. Hydrogen currently IS a fossil fuel at this point. Wiki says 95% is produced from natural gas.
    So even if it was better in every way it will can’t ever be as good (efficient, clean, pick your synonym) as just the stupid fossil fuel feedstock it came from.

    1. Except, of course, for how the number one problem with fossil fuels is the co2, which is optional. There’s successful plants using natural gas to produce carbon powder and ammonia, emitting no co2. (They buy renewable power instead of using up some of their product to generate the power needed, but they could also be set up to operate solely from natural gas and still not emit co2).

      1. “There’s successful plants using natural gas to produce carbon powder and ammonia, emitting no co2.”
        Yeah, less than 5% of them, probably less than 2% of them. That’s basically research scale. H2 production is a fossil fuel. It comes from fossil fuel and produces CO2 at an industrial scale. There is a vast difference between a process that exists and the process that dominates.

        1. The point is that to say hydrogen is a fossil fuel is an oversimplification that makes it hard to discuss alternatives to the fossil fuels that actually matter. Hydrogen isn’t anything at all, that’s why we have terms like blue, turquoise, and green hydrogen. And by defining those terms we make it possible to push for the production of non-SMR hydrogen. And it lets us say that even though it’s not ideal that most hydrogen comes from SMR, it’s not in the same category as running a coal plant on cheap wet sub-bituminous or lignite coal. And given how it’s kind of a common element and way to get electricity from chemistry… we’re not going to want to paint ourselves into a corner on the subject. There’s too many ways we might end up wanting to use it, regardless of the specifics.

          Would I like to use the ch4 directly? Maybe. Certainly, it’d be better than a lot of fuels, and far better than flaring the stuff. And fast airplanes may not be the first place I would try using hydrogen. But getting away from airplanes for a moment, the thing about fuel cells for mobile shaft power applications is that they let you use an electric motor and a certain size of battery buffer, handling varying loads far better than a piston engine, plus not needing to idle or warm up the electric motor.

          Personally, I’d hope we make better batteries soon, and I’d like if we could make some better non-hydrogen fuel cells, but hey.

          1. Green hydrogen is a thing, but it isn’t done because it isn’t cheap. When the demand meets the supply, the production of hydrogen will turn to fossil fuels or the price goes up so much that nobody will use it.

            You could use ALL the wind and solar generators built and operating right now in the world, which amount to about 8% of the total electricity supply, and it could just about generate enough hydrogen for ammonia to make the nitrogen fertilizers to keep the people fed… there just isn’t enough green ENERGY available to make enough hydrogen at any price.

          2. @Dude, agreed that we don’t have enough power to use all our renewables on hydrogen!

            I just don’t want to hand out free torches and pitchforks to the people who would love something to use to smugly criticize anything that tries to be greener.

            Personally, rather than trying to use electrolysis for everything, I’d like to get the SMR hydrogen places to keep using methane but stop producing CO2 – pyrolysis is my favorite option at the moment. We can keep getting energy into our hands that way, instead of taking energy out, and then we have plenty of time to think about how long until there’s not enough actual fuel to drill for. That said, if we use electrolysis as a load if/when renewables are in excess for a few hours a day, that could be fine.

          3. The problem with hydrogen vehicles, or electric vehicles, etc. is that makes no sense to build and use them before we have the green energy to power them. With the slow pace of de-carbonization, switching from jet fuel to hydrogen is simply switching the smoke stack that emits the CO2.

            Maybe you’re making slightly less, but that has no point because the ultimate aim is to stop emitting CO2 entirely. If you can’t do away with fossil fuels, then the hydrogen airplane has no point anyways, so it’s the fundamental problem that matters – everything else is just window dressing and hype.

      1. > With any luck that will soon change using methods such as

        Aluminum requires vast amounts of electricity to refine from bauxite. Using that aluminum to generate hydrogen to make electricity is insane. I’m sure MIT knows better. Maybe it’s lazy journalism, or maybe it’s a grab for VC funding from ignorant people. Either way, it’s not a solution to our energy needs, our hydrogen needs, or our aviation needs. It’s not even *part* of the solution.

  4. Aeroplanes are clearly a much better potential use for HFC technology and it’s good to see an article that is fairly objective about their potential. There are a couple of points I think ought to have been covered:

    1. It was good to see the mention of how dirty H2 production is, but it would have been helpful to provide figures. In fact, over 98% of H2 production worldwide is currently not zero-carbon.

    2. It’s also clearly not true that Battery EV planes aren’t viable, given that the e-pipistrel is already FAA approved; that the Lillium air-taxi has had many successful tests and that the Eviation Alice passenger aircraft has already flown further on pure-battery power than this aircraft. With current battery technology, they’re only good for about 200 miles (45 minutes of actual flight), but there are markets for that (Manchester to Dublin) and if battery energy density improves as it has done over the past decade (about 3x), then we can perhaps see ranges up to 600 miles (or 235minutes of actual flight time).

    Still, a forward-looking article that heralds major changes to flying in the coming decades.

    1. >battery energy density improves as it has done over the past decade (about 3x)

      False impressions. You can make that comparison if you take the worst chemistry and compare it to the best, and ignore all other properties like price, flammability and shelf-life. Comparing apples to apples, it’s more like doubled in 12 years at more or less a linear rate. But that’s making the futurist fallacy as well, since the trend never keeps forever.

      Any technology follows an S-curve where the initial pickup can be approximated as exponential, the middle phase as linear, and then finally it reaches the limits of said technology asymptotically with diminishing returns. Lithium-ion battery technology had its exponential phase in the 90’s, now we’re in the middle phase, and we can already see the slowdown in the horizon, where the commercially and practically viable characteristics of batteries may reach 2-3x the best we have today, after a very long time in development.

      It’s not going to be that much better unless something truly revolutionary comes around.

      1. So, for instance, maybe 2d materials like graphene (which we’re still figuring out how to produce at scale) would do more with less mass. Or, maybe any of the thousands of alternatives is finally made to work well enough to use. I think it’s got to be some kind of fallacy to assume we don’t find or begin using any more innovative things when we’ve been finding new innovative things on a regular basis for generations.

        1. The thing about new discoveries is that you can’t plan for them, because you don’t know what you’ll find and when. Magic words like “graphene” don’t mean anything.

          1. Well, I actually was saying that we have recent progress on making small graphene flakes, which is nice for surface effects like adsorbtion. I wasn’t just throwing magic words at the problem. I was saying that we have been improving our ability to make something that we already know would be very useful. So we can easily plan for a world where we’ve produced it in larger amounts.

        2. > when we’ve been finding new innovative things on a regular basis for generations.

          The trail of bread crumbs has to stop somewhere; assuming new inventions and innovations around some topic or line of inquiry have to come around on a regular schedule is the same futurist fallacy – “the trend must continue”.

          1. I’m not thinking of a trend like you are describing, so let me try again. We have so many things we’re attempting, and a portion of them would constitute a leap forward in energy storage if we found a way to make them work. At minimum, every single one of them has to fail for us to never find another leap forward in storing electricity.

            Furthermore, we also have a bunch of other things we are researching or will research in the future as our understanding of the universe progresses. We can hypothesize about what we may discover and whether it may be applicable to energy storage. If we are to never again make a leap forward in energy storage, then every single one of those things must fail to improve on lithium ion tech as well.

            I’m sure if we solved all of the unsolved mysteries of the universe and built a machine able to place any particle in any location in a device with perfect accuracy, we could construct some kind of insanely good battery. Someone with time and understanding could come up with a list of ways that might work. However, it is much more likely we learn a little bit more than we currently know and/or get a little bit better at placing bits of certain substances somewhere near where we want them, and make a leap forward in batteries instead.

            Really, the whole reason we think we might get iteratively better at something is that we know we didn’t make a perfect version of it yet, and we discover how to more closely approach that. Sometimes the imperfection is enough that doing a better version constitutes a leap rather than a small improvement.

          2. The thing is, we already know what the theoretical upper limits are for technologies like the common Lithium-ion cell. The present day batteries we have come in at around 200-300 Wh/kg and the upper limits are in the range of 1000 Wh/kg which is about 3-4x of what we have today. Reaching that has diminishing returns where the ultimate limit will ultimately require infinite effort. You can never shave that last 1% off.

            A simple model is that halving the difference requires twice the effort or twice the time from the previous halving, so if we want to get from 1/3rd to 2/3rds at the past level of investment, it’s going to take 60 years instead of the 30 years we’ve spent so far. If we double our efforts, it’s still going to be 2050 before we got Li-ion batteries with twice the capacity.

          3. Actually, longer that that since the improvement up to date didn’t reach half the difference to the theoretical max, but I’m too lazy to calculate how much more.

            Either way, the point is, we know Li-ion today. Examples of other chemistries with greater energy densities have other problems, such as very short cycle lives measuring in a couple dozen to couple hundred cycles, so you can’t expect something to just come along and lift us to the “next level” right when we need it. Every path has its own pitfalls.

          4. > we might get iteratively better at something

            Our ability to iterate towards better batteries, or better anything really, is predicated by our general understanding of fundamental physics and chemistry, which advances regardless of our understanding of electrical batteries. The spending on this kind of fundamental research is more or less fixed regardless of market realities, and tends to remain the same regardless of increasing costs of advanced research.

            Consider this point over the Formula E-series of racing: the hype about the electric Formula racing class was that it would bring money for the development of better batteries. However, for any racing team, they can’t really spend the money on building labs for new experimental battery technologies. That would take so much money that they’d never get started. What they’re really doing is just buying what is available on the market at the moment, and the winning team is decided by who has the most money to buy the best technology so far. However, the best tech for the price isn’t the the cutting edge, because the cutting edge has the cost overhead of research, whereas the best bang for the buck is the previous generation – so this kind of competitive spending doesn’t really advance the technology. It benefits the commercialization of the older established research results. It’s the same thing with every other commercial prospect of technology – it’s never the latest and greatest that gets the big money, it’s what is most cost effective, mature technology.

            So, while we’re “iterating away” towards the better solution, the money and effort we’re spending is actually remaining more or less fixed, while the challenges we’re facing are increasing with each step we take. What does that sound like? Slowing down development.

    2. > With current battery technology, they’re only good for about 200 miles

      That depends on the size of the aircraft. When you scale things up proportionally, the weight of your fuselage and your payload capacity increases more than your lift surface, which means you need more power to fly. That’s why tiny battery electric planes can fly hundreds of miles, while a larger freight carrying planes could just barely hop.

  5. As usual, the question is which of the methods you use to store it and what you used to produce it – we know a portal to the atmosphere of a gas giant would be amazingly useful, but in the real world we need to produce and store the fuel. Personally, I like the idea of just storing it in simple molecules such as methane or ammonia (no carbon in ammonia), until and unless we can store hydrogen gas at low pressure with any reasonable mass and volume efficiency. (e.g. adsorbed onto graphene flakes or whatever) We already know how to store hydrocarbons and ammonia, and they aren’t that bad on a mass basis. And one pretty decent way to do it is to keep using hydrocarbons, but don’t burn the carbon portion. There’s places buying methane and renewable power, then selling carbon powder and ammonia.

    1. “As usual, the question is which of the methods you use to store it and what you used to produce it – we know a portal to the atmosphere of a gas giant would be amazingly useful”.

      Pressure differential would be amazing as well.

    2. Ammonia also has the nice property of being storable unpressurised in the fuel tanks of existing aircraft with some basic (not deep cryogenic) insulation, and burnable in the engines of existing aircraft with the addition of a thermal cracking unit (splits a portion of the ammonia into H2 & N2 to provide a lower ignition temperature). In other words, it’s a viable retrofit to existing aircraft fleets without major structural changes or loss of passenger/cargo capacity (as would be the case for in-fuselage pressure vessels).

        1. Luckily, even if you allow it to produce more initial NOx than diesels and don’t employ any of the other NOx reduction strategies we normally use, ammonia also can serve as the NOx cleanup agent so you don’t need a separate exhaust treatment tank like they do. For planes, I’m not entirely sure how much but they do already emit significant NOx.

  6. This whole pure hydrogen thing is complete BS. FTW. In case of CH4 we have massive storage systems with energy density to power whole f… Europe for days. Busses in many many cities are either troleybusses or CH4 ICE powered…
    Should there ever be energy excess in Europe it won’t make any sense to produce H2 when you can with only slightly worse efficiency go directly to CH4 with astronomical advantages and complete CH4 transportation and storage infrastructure in place.

    And getting some brand new CH4 for airplanes certified would certainly be easier than with H2…. but CH4 can be further converted to nice dense oily splashy kerosene and you can use existing……….

    1. Use nuclear as the energy feedstock for the power-to-gas and you’ve got something. Instead of having to scale back from high efficiency use the extra power from a reactor (when not in use in the grid due to demand) can make synthetic fuels out of atmospheric CO2 and water through this process.

      Also, plasma gassifiers for waste disposal fix a number of problems we have with landfills and micro-plastics in the environment AND generate Syngas as a byproduct!

      We have plenty of tools to fix this, but as long as we’re fixated on “MUST DRIVE ELECTRIC CARS AND CHANGE EVERYTHING OVER TO ELECTRIC OR WE’RE DOOMED! D O O M E D ! !” We’ll never get anywhere.

      We know how to handle and manage petrochemicals, let’s start making them instead of pumping them out of the ground and start managing our planet properly!

  7. “Note, however, that this comparison is of the fuel itself, and does not take into account storage infrastructure like the tanks required to maintain hydrogen at the correct temperature and pressure.”

    Yep – lets not count storing it. Which is one of the significant problems with hydrogen. Not to mention transporting it and creating it…

    And electric cars still have significant problems ie could the world make enough of them to make a difference? And replace the batteries every 10 years? Are we going to all contract our driving ranges? etc etc.

    I just can’t see any solution to the CO2 issue making any significant difference in my lifetime. I agree, they are all worth trying, but we should be planning on none of them being successful. Sort of like fusion, which has been 10 years away for the last 50 years..

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.