Is Hydrogen-Electric Power The Secret To Zero-Emission Flight? 

Bit of a wild landing at 13:40 with a stuck left brake nearly taking them off the runway. The pilot earnt his pay.

You always hear the gravimentric energy density quoted for hydrogen by itself. I'm glad she's talking about the tanks, but I'd love to see a breakdown that's more quantitative. Any of the real-world tanks I've been able to find bring the energy density down by 95% or more once you consider the mass of the tank needed to hold it. For example, a tank to hold 5kg of hydrogen weighs 92kg.

I love her bit about storing fuel “including in the wings”! That’s where MOST is kept - and not only because it’s convenient, but because its mass is used to relieve the various bending moments across the span. If all the jet fuel was kept in the fuselage - and in the case of a 747 we are talking upwards of 150 tonnes for long range sectors the wing/fuselage attachments would be enormously strong and therefore heavy. The same issue with wing mounted engine pods is relieved by wing tanks. Interesting to find out how H2 copes !

As "energy dense" as hydrogen is you need to count the casings, tanks etc in that for an actual apples to apples comparison of power to weight ratios. Not anti hydrogen, just for realistic comparison parameters. We don't judge pure lithiums energy potential, we judge battery pack kWh density and should do similar with hydrogen systems.

Yeah I'd say hydrogen energy storage is a bit up in the air at the moment.

Love your work, Imogen 👍

As soon as you showed the plane and they said they are retrofitting it to be hydrogen-powered I thought "I bet the whole cabin is filled with tanks and fuel cells". And it is. I didn't hear a single word spoken about how they plan to actually integrate this technology into an airframe and still have passenger or cargo space. As an experiental aircraft, good on them, great job... I just dont see the path forwards to commercialization. External fuel tanks might help, but would only get them part of the way there. With hydrogen-powered cars, they typically weigh more than a battery-powered equivalent, and have less space for passengers and cargo. Often they have no truck or frunk at all. And maybe with flight, energy efficiency doesnt matter as much as with cars, but fuel cells also rely on exotic, expensive metals and they are also not forever but have to be reconditioned or replaced far more often than straight batteries would. I just dont see how its possible especially with retrofitting... Not without losing passenger AND cargo space. Both of which are typically maximized on commercial aircraft to help cover the expense of the fuel. How is an also expensive fuel (and regular fuel cell replacements) going to compete with less cargo and passenger space? It sure feels like by they time they have all of this solved, we will have lightweight, high energy density batteries that will recharge ultra quick.

Exciting times for aviation. Great presentation :)

Keep these types of informative videos coming! Good quality, good content and excellently presented.

Well narrated and very interesting video.

An excellent presentation - fascinating to know what is going on with aviation. Thank you.

the modular electrolyzer is the bigger thing to me. sure getting short haul flights greener is better for everyone, but if we can do trucking or shipping with hydrogen will be great. especially if you can incorporate it into ships then they could make their own fuel while underway, in a renewable fashion. or at warehouses, depots, and rest areas you could produce fuels and be cleaner and better than fossil fuels.

A simpler intial description of this proto-type is that there is a standard aviation fuel turbo prop on the starboard side,but a hydrogen fuel cell prop on the port side with a back-up pack of lithium iron batteries during trials.

Imogen! Great job at FLC North on this topic. May I repeat my question? When will Airlines see value parity for domestic routes? The FCL panel suggested we were already there…

Interesting you mention contrails very briefly. There are a lot of studies about these right now but it does seem aviation coild become a net cooler if we utilised contrails to our benifit, but it's not particularly fashionable to talk about

Congrats on 1M subscribers!

The way to go! What about a look at the huge frightships? Any development der?

I’m not a scientist or engineer in any particular discipline. Like most folks, I’m genuinely curious and fascinated (and worried) about the old and current technologies we use for transportation. Granted there are significant challenges with low carbon technologies but I wonder if a fusion of fuel, electric and hydrogen power is initially a better option until the actual technology can be reliable developed to run transportation at a true zero carbon emissions standard.

Good to see real development into bringing hydrogen into the air flight world. Thank you for sharing!

It seems there's still a long way to make it feasible for long haul flights but this could be great for shorter flight when speed and altitude are not an issue. Travel between small islands probably the best use case since other short routes are best covered by trains.

This is awesome, good to see we're trying to make hydrogen work. I really think this will win over batteries, just a matter of time. Not an easy job to make and store the stuff, but I imagine a future where gas stations will make their own hydrogen greenly and sell it to customers. The only emission will be the occasional solar panel replacement and some maintenance.

Thank you

Hydrogen is improving at a modest pace. Battery tech, EV motors, and solar seem to be improving faster and faster. Sort of how consumer electronics spawned the battery tech needed to make EVs viable for consumers, then commercial trucks, and so on, I can see this massive swing to EVs on the ground rub off onto aircrafts. The energy density needed with possible solar panels on the aircraft make full battery electric the way to go. It would be easier to build and maintain. Imagine airports no longer needing jet fuel services or hydrogen services. Just large battery storage and solar systems. Maybe battery swap for aircrafts will make sense, but considering the time it takes to load and unload crafts, maybe rapid charging will be all that is needed. Hearing this guy say 2035 for their aircrafts makes me think full battery electric aircrafts have a shot at becoming the new standard.

If you want to know about renewables and the future fully charged is the place to go, and this report is outstanding, thank you. For all the naysayers out there this shows what is possible with hydrogen fuel cell flight.

I would imagine in the future when these might be operating they would integrate these fuel cells into the leading edge of the wing, this should cool them fast and help prevent icing at the same time

With energy density you do have to consider the weight of the tanks or battery packs and engine components obviously.

With liquid jet fuel, the plane gets light as you use the fuel. You can also save weight by not filling up for shorter trips. With electric, the weight doesn't change unless you change out the batteries for smaller ones, but then you have to plan better weight distribution. The hydrogen, the weight doesn't change much because the hydrogen doesn't weigh much and you still have the weight from the tanks.

That was really cool to see some early footage of planes swapping to Hydrogen fuel, & I love that they're producing green energy on-site. Everything's in test mode currently, but I can totally see the future being even better

Has episodes of fully charged said in the past that the issue isn’t energy density by weight but by volume?

Now please do a video on Eviation as well :)

It might be possible to minimise battery capacity for aviation hydrogen power systems because unlike with surface transportation, the overwhelming majority of any given flight is at a constant, very specific power level. But it's still impossible to completely eliminate the batteries because of takeoff and landing. The thing that hydrogen proponents are very careful to downplay is the fact that any "hydrogen-powered" vehicle is really just a BEV with the addition of the weight, complexity and failure points of the hydrogen-fueled electricity generator. It is not possible to throttle fuel cells the way ICE or Electric motors MUST be throttled in normal use, so fuel cells are really just range extenders for what is otherwise a pure BEV vehicle.

Curious how much hydrogen is lost to leaks in the system. Is it more difficult to keep atomic hydrogen contained compared to molecular gases? seems like that would be an added challenge in storing enough for long range flight

Great content

350 bar is about 5,000 psi. There are 700 bar composite hydrogen tanks, too. That's a lot of potential energy that can change to kinetic energy very quickly.

Thank you.

Radical new efficient propeller designs could fit well with developing hydrogen/electric power trains.

Very early days, but great somebody is trying something

Making the tanks structural would make sense.

Good luck with hy flights have a safe journey God bless ❤️

This is what effective prototyping and R&D look like. Messy demo units that are big, clunky and inefficient, using off-the-shelf components that aren't a great fit for the application, loaded alongside a backup and a backup-backup... but they work anyway. ZeroAvia have built it and flown it and proven that it works. We're very used to seeing mature commercial technology, which has had decades of refinement. This is the first, ugliest version of this technology and I wish ZeroAvia the best of luck with the next version, and the next version, and the next version.

I find zero emission short haul flight an interesting proposition as it could well make trains far less compelling as it removes most or all of the environmental edge they have. If you can fly intercity across a given country using fuel generated on site be it hydrogen or battery electric then you remove the need for investments such as HS2 with its massive costs and negative environmental impact.

Why don’t you guys say “if you have been, thank you for watching” anymore? Great video. Sounds like a very difficult task but I can see the “easiness” of producing H2 on site at airports at least…, so reduces all those issues with transporting it, distribution… 👍👍. It’s just such a hard fuel to keep within the tanks, no leaking…

Be perfect for Island hopping and internal flights in Australian outback.

Really interesting topic such a pity about the script, for example feeling it necessary to point out that the plane is surrounded by air, and describing the hydrogen creation process as out "pops" the hydrogen. It would be good to see the same article aimed at adults.

Just as a general point, you need to get Bobby Llew to talk on GB News to correct them on their hopelessly out of date "facts" on EVs...! I imagine RL may well break out in hives at there mere thought of talking to GBN, but slather him up in E45 and I'm sure he'll survive.

... the hydrogen-electric, the fully-electric also. And, later - even purely magnetic engines, as well. Yes, to all that. Finally, in the future, (that is considered a future to this moment) the engines are purely magnetic (rotary-system based), (by that time will be called RMG's). Only collecting from the existing environment energy to run, and is also 100% pollution free, and the most-powerful flight power, ever. Presently, moving away from the fossil fuels to power the flight (irregardless the carbon issue or not) is a very good move. With an addition, that, in the future - it will be indeed revolutionized - not only the pilots, but even the passengers onboard (supervised by the PIC's) will be flying and assisting at it. Everyone onboard for a flight will be considered: a team member :).

A good video. I did a search after watching it and it looks like hydrogen as well may have the same contrails problem but more research is needed.

The chief of strategy look and sound like the younger version of Jeremy Clarkson...😅. Way to go by the way!

@fullychargedshow One criticism I would like to point out when it comes to fuel cell-powered aircraft is that a lot of people haven't got their heads screwed on correctly about realistic efficiency versus power and very commonly assume that a 30%-40% efficient turbine powered aircraft would be less efficient than a fuel-cell powered one. In aviation, the opposite is true despite the conventional logic around hydrogen fuel cell cars and engines. However, in reality, that common 30-40% figure includes the *propulsive* efficiency, *which is largely independent of the drive-train type but dependent on the propeller and environmental conditions.* not just the thermal efficiency. For example a GE90 or Trent XWB (I am aware this plane is a turboprop but it still requires highly engineered turbines and the argument still stands on the power requirements anyway) is actually capable of above 50% thermal efficiency, but add on the 70% propulsive efficiency and you get the cliche'd 30-40% figures. Then add in the fact that aircraft turboprops and turbofans have power levels for those efficiencies FAR in excess of fuel cells, and the fact that many hydrogen drones exhibit fairly low efficiencies of roughly 30%, add in the extra motors needed, however lightweight they are, and one understands that there is no current realistic case optimal case for a non-combusting aircraft despite the 'futuristic' appearance of fuel cells. And then there's the durability reductions with electrochemical fuel cells. If the fuel cell paradigm was truly advantageous, contemporary aircraft and ships would be using hydrocarbon-consuming fuel cells. For the reasons above I would be skeptical of this company.

Hydrogen certainly has a place in the future of aviation but the main problem that these journalists seem to not understand is that hydrogen may have a high specific energy but it’s energy density is not very good which is more important to Aircraft designers. Yes, there is a major weight saving but that can quickly disappear when you have to introduce heavy insulated tanks, active cooling systems and a need to store it in the fuselage rather than the wings due to aeroelastic constraints. Therefore what is needed is a new approach to aircraft design rather than modification of existing designs.

could electrici ty be used for the initial take off and landing and then other fuels used for flying the plane (I am making the assumption that take off and landing are the most inefficient parts of a flight)

I've always been very anti-hydrogen for vehicles, BEV just make more sense. But when it comes to flying batteries really don't. If a plane is running at half capacity, you can just stick less hydrogen in it. But if its got a battery, unless you've got swappable ones, that battery is going to weigh the same with 10% charge or 100% charge. Plane's gain efficiency the further into the flight it goes as it uses fuel and gets lighter and lighter. A battery powered plane has to have the same efficiency at take of as it does at landing, and unless we get some fantastic new battery development, that just isn't practical.

I wonder if liquid hydrogen could improve things. While it is really, REALLY cold, it can be kept at atmospheric pressure. So no sturdy tanks. And it has more energy per cubic-meter. So more oomph in the same space. And theoretically, you could just pour it into the tank. (not sure if that is a smart idea) While it will just evaporate and be gone after a while, that is no problem, as the plane will run exactly on these vapors. If it is not boiling into a gas fast enough to feed the fuel-cell, you could even expand it in a turbine or something. there is a lot of energy in a liquid that turns into a gas spontaneously. (see also: liquid N2 motors) While liquefying H2 takes an arse-ton of energy, you might get it back in the re-gassification. And if you're really putting your energy into making inefficient H2, you can go on and liquefy it.

Hydrogen is only as green as its source. It only exists (on Earth) in forms bonded to other materials, from which it must be freed in order to be used. Currently the cheapest material from which to get hydrogen is natural gas. So, todays hydrogen, at best, is only as green as natural gas. This is why, when you look behind the push for hydrogen as a fuel, you find the fossil fuel industry, since hydrogen can also be generated by processing other forms of petroleum, and even coal. The ONLY way for hydrogen to be green is for it to come from splitting water into hydrogen and oxygen, using energy from solar, wind, hydro, or geothermal. Currently that is inefficient, and therefor not cost competitive with fossil fuel derived hydrogen. (on edit) at 10:35 I see they are addressing this. Good on them.

Regarding Welding of each High Pressure Tank, have all welds been X-Rayed ? U don't want any Micro Leaks occurring...

9:45 DEJA VU

Yellow hydrogen can be lower in terms of greenhouse gas emissions than green hydrogen, as nuclear reactors can use high temperature methods, such as high temperature electrolysis, thermal cracking or the sulphur-iodine cycle, which operate at higher efficiencies than regular electrolysis. Thermal cracking can technically be achieved via concentrating solar power, albeit at lower temperatures and lower efficiency.

4:56 Turbine blades should be propeller blades

And if you have been, thanks for watching - just thought I'd put that in as Imogen didn't ;p

5kg of hydrogen would give you, with my calculations, less than 100kWh usable energy after the fuel cells. We have cars running on the roads now with batteries in the 200kWh range. Looks to me that battery electric aviation can fill quite a big niche here.

I'm interested in seeing if hydrogen is a viable secondary propulsion system for sail boats. They drag a propeller that generates electricity to charge batteries, why not hydrogen as well?

ah never knew condensation trails cause most of the warming effect, always good to get some info out of youtube

Take the hydrogen, react it with captured CO2 and make methanol. Can be stored as a liquid at atmospheric pressure and at room temperature, unlike hydrogen. No need for special high pressure tanks, just put it in the wings like regular fuel. Maybe needs different seals or something but you could run your regular turboprop engine on it. Methanol is 1/3 the energy density of kerosene so long haul flights wouldn't work, but short hops of a couple of hours would work well.

Except for full-sized airliners (e.g. 737 MAX and larger), hydrogen-fuel cell technology is "a fool's errand" - With exponential improvements with battery energy density and orders of magnitude improvements in aviation motor efficiency, ALL REGIONAL FLIGHTS will quickly change to all-electric planes, whether by replacing propulsion systems, or completely NEW aircrafts, which can take advantage of a "first-principles engineering" approach (vastly more efficient and easier to fly)

Whatever happened to low pressure high density Nickel-Metal Hydride tanks?

You know your stuff on aviation here 🥰🙏 good job

2:54 Bit of a weird discussion about energy density, given that (as the graph shows) aviation fuel has something like four times the _volumetric_ energy density of liquid hydrogen. Seems to me that's the factor you should be considering since the gravimetric energy density is ruined by the weight of the tanks __

but they forget the bennefit of have a electical motor in the front wheel, for taxi to runway with lot less energy to activate extra range. perhaps a small electrical motor in each wheel, used for taxi, also have be used to rotate the wheel up to landing speed to avoid rummer burn duing landing, that will encrease the lifespan of the tires. and that will demand less rubber waste.

SAS have just sold tickets for the first flight in 2028; it seems to be hybrid planes Heart Aerospace ES-30

if it's 3 times as energy dense as electric in terms of weight as a complete system, it probably won't be worth it in a couple of years when battery energy density becomes twice as dense, meaning the loss of energy in making the hydrogen and marginal differences in power to weight will make it less viable unless they can get the containment of the hydrogen lighter

Was that a left wheel/brake lock on landing ?

What about ammonia fluid?

They even admitted the cooing requirement is larger than the enormous fuel itself !!

It’s the physics of hydrogen that makes it an impossible fuel since compressed to 10,000 psi as in the Toyota Mirai it’s still seven times the volume of kerosene for the same energy content. The weight of those tanks is in excess of the weight of hydrogen within the tanks. To say nothing of how hydrogen attacks metal causing embrittlement. many people think it’s just a matter of the technology getting more developed, but it’s the nature of the hydrogen atom itself. That is the problem. People constantly discuss the energy density of hydrogen as being amazing with respect to weight, but weight is not the issue, it’s all about volume. Take any jet fuel powered aircraft and increase the volume of the tanks by 11 and tell me how much room you’ve got left. This is also to say nothing about the cost of hydrogen from electrolysis being about seven times the cost of kerosene. Hydrogen is so bad That it’s extremely obvious that it will never even beat out battery powered aircraft, making me believe that it is one of the ploys of the fossil fuel industry to promote hydrogen so that we will be distracted from other meaningful ways of providing fossil fuel free transportation.

So much tip-toe-ing, where boldness seems to be needed! Before u realize it, someone else will overtake you! Experimental stages require risks!

😳9:45 rather LARGE OVER-CORRECTION, nearly wobbled...😳

I'll be that guy . FIRST.

Could you use the pressure of hydrogen to power the motor and it reaction in the fuel ?

Last time I checked, not very long ago, their fuel cell system had a maximum output of about 100 kW, to claim that the battery system is there for redundancy in providing power to the 600 kW motor is more than a stretch. The "hydrogen electric" side is basically a battery electric system with a hydrogen range extender, not a even good one, but a very bad one, very bad in multiple ways. The main problem with replacing fossil fuels is not lack of technically viable alternatives, it's the lack of economically viable options, because fossil fuels are extremely cheap to produce. Hydrogen is the fossil fuel industry's last big hope, as any resources intended for transition spent on hydrogen will make the period of business as usual longer, and if hydrogen reach wide use as a fuel in the foreseeable future, it will have to be produced from fossil fuels mostly, to be economically viable. One of the huge problems with fuel cells for aviation is their ridiculous power density, the higher power density you want the lower the efficiency you'll have to accept. This is still an issue for fuel cell cars, but they have managed to cram in acceptable powerful systems with kind of acceptable efficiency, with kind of acceptable space and weigh penalty, for passenger cars! Not anywhere near good enough to replace turbo props. Yes, you could put hydrogen tanks everywhere, but would you really want to? Just the pressure alone makes them more dangerous than jet fuel tanks, and if a tank bursts the hydrogen is very likely to explode, and make the other tanks burst and explode. For aviation combustion engines are totally superior to fuel cells. Sure, you create NOx, but assuming "clean" hydrogen, that's the only relevant drawback, and if only used in situations pure battery electric systems aren't viable, that's not much of an issue. Zeroavia lists water vapor and contrails as relevant issues, which they are not. They also claim fuel cells are far better than combustion in that regard, which makes absolutely no sense at all, the amount of water produced is determined by the amount of hydrogen that is used, which also dictates the amount of energy extracted. Sure, you can catch the water vapor from the fuel cell system, but if you wanted to you could du that with a piston engine powering a generator. Also, there would be about as much heat and exhaust from a fuel cell system as from a combustion engine at the same power output. Actually at very high power output for their size and weight, like almost comparable to aviation piston engines, current fuel cells would have much worse efficiency than a good piston engine, and therefor produce more heat and exhaust at same output of useful power. "Yeah, maybe so, but fuel cells are a new technology that catch up and surpass everything else!" Nope, they're not new, the first fuel cell was invented 185 years ago, which is well before the first rechargeable battery, well before the otto engine, and the diesel engine.

So what is the energy density of hydrogen when you factor in the weight of its container?

4:56 - Pure gobbledygook. Turboprop engines have gearboxes which allow them to produce as much torque as would ever be desired by an aircraft designer, electric motors offer no advantage in this area.

0:07 Framerate missmatch...

Recharge the battery prior to take off

The killer when burning or using a fuel cell hydrogen be it a car, lorry and esp aircraft is the cost of it... at the best of time you looking at x4 the cost vs liquid fossil fuels which means a lot higher flying costs

4:54 - If it is an electric motor - it no longer has turbine blades ;)

I love the initiatives - the reality however still differs (minimum endurance standards are the most difficult to meet for electric aviation - that last 30-45 minutes of "minimum planned fuel reserve" does it in for batteries, hydrogen too, probably- other energy carriers are a must (green-fuels are the simplest conversion). Vegetable oils are so much easier to use instead of Jet-A1 than anything hydrogen. The sheer quantity of energy needed for heavy aviation... By all means, green up old school GA.. ...Actually this video "may" be the future - one engine with Vege oil, the other with a hydrogen stack, the ultimate parallel hybrid (go for central APUs and pod based electric propulsion, the APU can be green-oil or green-hydrogen based, or a bit of both... "cooling air" can be thrust optimised - like in the P-51 - 80 years ago.

Bad spin, if you want to compare the energy density of hydrogen without the weight of the tank compared to batteries should you not leave the battery out and only weigh the electrons?

The hydrogen contained in tanks provides twice the energy density of the batteries. Then there’s the weight of the fuel cell and everything to make the system work. It would be interesting to see an energy density comparison of a complete hydrogen system compared to a complete battery system. Battery density will probably double in a few years which would mean it’s simpler, and consequently cheaper, to provide the motors with electricity direct from batteries. While it’s good to see this innovation, the battery industry is working hard looking for ever more energy dense batteries. The hydrogen atom isn’t going to change its properties. There will be a point where batteries are a better option.

In the absence of suitable batteries today, hydrogen is being demonstrated here as a way to store electrical energy until technology is ready. Hydrogen per se has to be manufactured and stored, whereas electric supply is ubiquitous. This is an interim solution. CATL has already started producing cells rated at 500 Wh/kg. Doubling that figure (a fairly realistic objective) will enable aircraft designers to use batteries to power most new aircraft by the 2030s. Systems using hydrogen for electrical storage are very useful in developing the approach needed for large construction machinery and international shipping,

Can we get some sub-titles? Imogen's accent is so different than my American accent that I can barely understand what she is saying.

I don't know how much water is required to make H2. But if H2 powered (anything), in this case, aviation, were to become common place, I wonder how much of an impact the increasing frequency and severity of droughts would have on (reliable) production and supply. TBC: I'm not trying to be an H2 naysayer here, merely wondering aloud.

It will only be clean in my books when the entire production and storage process is "clean."

Hydrogen is energy dense in terms of weight. But not in terms of volume.

Comparing hydrogen with its lack of green hydrogen with SAF with its lack of material is bizarre. Both solutions are vapourware.

Would Amonia be a viable fuel source? You would not need the high pressure tanks.

Has anyone from Fully Charged Show read the article from Rowan Atkinson about ev’s today on the Guardian? It is an article full of inaccuracies and truly disappointing from the Guardian that they would publish such a piece. I sincerely hope someone from the Fully Charged show will help refute his report on the future of EV’s.

CH3 FTW

Hydrogen and aircraft, what a great idea! Why has nobody ever tried that before?

Their biggest obstacle is economic. Hydrogen fuel cells are expensive, hydrogen storage is expensive, and hydrogen fuel is very expensive - with "green hydrogen" being even more expensive. It's hard for any commercial airliner to justify the cost and difficulty of switching to hydrogen when the fuel costs nearly double.

It's a cool experiment, but I'm afraid doomed from the start. Hydrogen has a ridicolously low volumetric density. It's difficult to store, good luck designing pressurised hydrogen tanks in the wings. We are still a long way in producing green hydrogen at scale, and even when it happens, most of the renewable energy is lost in electrolysis, compression, conversion. New 500Wh/kg batteries exist, this would make a BEA possible. The good thing is that their work would not get lost, electric powertrain developmenr is still very important. just swap the fuel cell with these new batteriea and fly :)