For anyone confused about the "hydrogen is 3 times as energy dense as jet fuel" vs the "hydrogen is less energy dense than jet fuel" statements made: Hydrogen is more energy dense by WEIGHT but far less energy dense by VOLUME.
The other way round, but yes, volumetric and gravimetric energy density are the issues at hand, and especially volumetric density is a problem for hydrogen.
@Victory in Truth Also, (just adding onto the above reply) Real Engineering has a very fantastic video explaining the problems with hydrogen (including density and storage issues) if interested. Been awhile since I saw it but I remember finding it extremely helpful.
I believe even the gravimetric energy density statement is disingenuous. As that only holds true if the hydrogen isn't stored in a container. Which seems impractical..
I feel Hydrogen would be a great choice for big tankers and cargo ships. Where weight and space isn't much of a constraint. For airplanes I don't think we will see much of a change in a few decades.
1970s USA already had hydrogen fighter planes. i dont know about the range. but they worked. it was made just incase US airforce ran out of oil. there was also a Nuclear powered military planes.
Totally agree. ... but that won't stop people to to build investor-fleecing schemes around some known principles that only worked for a few milliseconds under ideal conditions in a lab - resulting in Sci-Fi videos like the ones from Bloomberg or the other feelgood-eco-tech Gurus... (edit: wording fixed: "conditions" inserted)
Fluff piece, an executive in the field mixing up energy density and specific energy... Yes hydrogen has more energy per mass than jet fuel. Unless you include the pressure vessel you need for storage, and the loss of cargo space, due to the low density.
Tongue in cheek, maybe they think that using hydrogen will make the plane lighter, after all, the Hindenburg used hydrogen for lift. But then again, we all know what happened to the Hindenburg
What? As explained above it was volumetric versus gravimetric density - and the comments were made by the journalist.....not the executive(s) plural in this piece. You probably need to pay closer attention!
Yeah i don't see a feasible way of storing hydrogen in a modern plane design efficiently. Hydrogen pressure vessels need to be cylindrical so they wont pack well in a half a cylinder under the passenger cabin and in the wings like liquid fuel does. Maybe if you sacrifice a part of the whole fuselage and put a big tank in the middle of the plane that'd work packing wise. You'd need to put it near the wings or it'd probably unbalance the plane sitting in the back, then it would split the cabin and take up seating and cargo space cutting into the design's revenue making potential Hydrogen planes are probably a dead end just on storage alone.
@@lief1 youve just described the entire problem with hydrogen on planes. this is why investment is needed, or else they would have started being rolled out by now. you cannot efficiently store hydrogen in a modern plane design. this is known fact. the retrofitting is for testing and proof of concept only. the future is not cutting seats to put tanks at the back of the plane, its reshaping the entire body to accomodate the new fuel system. if it works out cheaper long term, it will be done, especially since theres an impetus to create less damaging technology whether or not it is cheaper anyways due to the risks to our food, water and land thatd be much more expensive.
Another overlooked problem is hydrogen leakage. Hydrogen has a flammability limit as low as 4% and a detonation limit as low as 18%. How do you prevent airplanes from exploding?
It’s not just the fueling structure that’s the reason hydrogen didn’t take of. There is also the fact that hydrogen is very hard to store because it such a small molecule and will escape almost every container over time. Second is the very inefficient production of hydrogen. Third is supply and demand. „Because we could use hydrogen for everything that doesn’t mean we should use it“
Thank you, a voice of reason finally! All this hyperbole on hydrogen is complete rubbish. The production, transfer and use of hydrogen is marred with inefficiency, high carbon footprint and unsustainable operating costs. This video is nothing more than media hype
@@pantalome H2 for most transport is a nonsense (maybe for trains in not electrified lines, or ships). H2 for clean heavy industry is really needed. It's amazing how they can remove almost all coal in steel production.
NH3 overcomes a lot of the storage issues as the pressures required to maintain it in a liquid state. NH3 is liquid at 1 bar at -30C and it's -40C ish at 30k feet. It would need insulated tanks and refrigeration at higher temperatures when the engines are not running.
The most practical way to store hydrogen is to react it with carbon dioxide to form a hydrocarbon that is liquid at atmospheric temperature and pressure. The future of aviation is synthetic hydrocarbon jet fuel produced using renewable energy instead of fossil fuel sourced jet fuel.
Many experiments have been done with H^2 as an aviation fuel. Storage is not the only problem mainly Bleed off thru subduction. But the main problem is Hydrogen embrittlement of engine components.
These would be solved or accounted fot. Embrittlement is a function of water content and temperature along with hydrogen. Storage is getting better. But I'm just observing.. don't know the total EROI.
2:00 I find it quite revealing that he says the energy density of hydrogen is 3 times higher thant that of jet fuel, and doesn't care to mention that the energy density of hydrogen by volume is 6 to 7 times lower than that of jet fuel. Thats a big design problem for hydrogen in Aviation.
@Flame it was. Problem is he didn‘t mention that and also didn‘t made the differentiation. Its cherry picking to deceive people. Either that or He doesn’t really know what hes talking about
@@ryanthompson3737 „they“ is a completely different person to whom I was referring to. I‘m not accusing the maker of this video, I am accusing the actual person that was speaking.
@@musaran2 The hydrogen in the universe is mostly in stars (e.g. the Sun). And the hydrogen on Earth is part of molecules (e.g. water) and it takes energy to extract it. And the cheapest and most common hydrogen production process emits a lot of greenhouse gas.
Hydrogen is the most abundant element in the Universe (except on Earth), just like nuclear fusion is the most common method of generating power in the Universe (except on Earth). You opened the video with a skewed truth, and kept going for the rest of it. An hydrogen powered airplane is impossible to build, because the weight of tanks to store compressed hydrogen are simply too heavy for airborne vehicles. It is possible to use cryogenic hydrogen for aircrafts, but it become a problem for long haul flights, because of evaporation...
Hydrogen can be synthetically combined with biofuels to make jet fuel and run our present jet planes. Liquid hydrogen can run a jet plane on longer distances than our present plane. All of our fossil fuels are hydrogen, all of our bio system is hydrogen all of the water is hydrogen.
As an elektrical engineer I still ask myself how the replacement should work for planes like the A320-neo. * 24'000ltr Kerosin (240 MWh) whould need to be replaced by 7200 kg H2 with at least (!) 73'000ltr of volume even when liquified. * The A320 has about 2700l/h consumption, i.e. 27MW. With an efficacy of e.g. 70% this means about 19MW mechanical power. Replacing that with an electric engine would mean about 172 to weight compared to about 2x2.6 to of the existing engines. Sorry, I don't get it how that shall be replaced with H2.
you're right. That's why it won't. From a certain plane size you have no way but to directly combust hydrogen. this way, the only inconvenience is the 4 times bigger, heavily isolated and pressure conform tank.
Well that's a big backflip! 1:40 The energy density of hydrogen as fuel is 3 times that of jet fuel... 5:50 the energy density of hydrogen is less then jet fuel...
1:44 is energy density by mass (hydrogen is quite lightweight and planes like lightweight). 5:53 is density by volume, kerosene is a liquid at airplane temperatures, hydrogen not so much. Stored as a gas under high pressure, or a cryogenic liquid, it's never going to be as efficient as wet wings. If looks like bio-kerosene (aka Navy Green Hornet) is a much better idea than this.
I simply wanted to point out the contradiction. They should have specified how impractical it would be to run airplanes on liquid Hydrogen ( 1:44 ). It may have a higher mass density but a lot of energy is required to cool it to liquid form. Storage is also a lot more difficult
It's three times as dense, yet it's less dense? Man, don't use energy density for energy/mass, only for energy/volume! Energy/mass is called specific energy!
Well, you are partially correct. The actual commercial aircraft will use a hybrid fuel of 20% hydrogen together with 80% ammonia. Ammonia is a much better container of hydrogen than hydrogen itself, but its combustion is slow so it requires something else like hydrogen to be added into the mix to speed up the combustion process.
@@jonathanodude6660 there are lower energy ammonia production methods being developed. If using ammonia is the only way to get long range flight then it doesn't matter too much how efficient it is. The only other non fossil alternative is synthetic fuel, which requires capturing CO2 from the atmosphere, which is extremely expensive. Nitrogen is enormously easier to obtain since it is most of the atmosphere.
@@jonathanodude6660 Canadian 123 is just ignorant. The combustion energy for hydrogen is 39,5 KWh/ but 1 kg liquid hydrogen is 14 liter. How to fit it in an airplan The combustion energy for ammonia is 5,2 KWh/kg only. And the energy demand for the Haber Bosch process to produce ammonia is 10 KWh/kg NH3. So, where is the benefit of ammonia. Only a fool would tell us anything about the benefit of ammonia.
@@wilfriedschuler3796 I knew the numbers wouldn’t make sense. Combusting fuels we make ourselves only provide benefits if we make the fuel using excess renewable energy. If we have to burn fossil fuels to provide the energy required to make them, we might as well just keep using the fossil fuel. Doing that would use less energy overall.
@@adrianthoroughgood1191 think about what you’re saying. We have to make the ammonia. It does matter how efficient it is. We don’t make fossil fuels. You’re saying that if we burn 100 GWh worth of natural gas to make some ammonia, then we get 20 GWh back from burning the ammonia, it doesn’t matter because in the future we hope ammonia production will get less energy intensive? Why not just use 20 GWh of natural gas and skip the ammonia which wastes 80 GWh, then we can do it 5x more with the same amount of energy? Also synthetic fuel does not require carbon capture. There are lots of carbon sources on the planet. Nitrogen is easy to obtain in its gaseous form, but it’s extremely unreactive and so using it to produce anything is difficult, expensive, energy intensive and requires toxic heavy metals.
You wanna know how you can immediately identify articles that are overhyping technology stories? When they use tentative language like MIGHT BE or COULD or MAY or any other such synonym. I speak from experience of 20 years of reading/watching stories like this. Stories about tech that are written by people who clearly have no idea about technology.
1:44 is energy density by mass (hydrogen is quite lightweight and planes like lightweight). 5:53 is density by volume, kerosene is a liquid at airplane temperatures, hydrogen not so much. Stored as a gas under high pressure, or a cryogenic liquid, it's never going to be as efficient as wet wings. If looks like bio-kerosene (aka Navy Green Hornet) is a much better idea than this.
Both statements are true. Quite often people want to make a specific point and, disingenuously, omit the required qualifier (volumetric or gravimetric) in regards to energy density. H2 has the highest gravimetric energy density, but one of the lowest volumetric energy densities. While planes do care about weight, it is not nearly as much an issue as is volume, since volume translates directly into the required size and therefore drag of the airplane. Of course that can be somewhat alleviated by going into high pressurization and/or supercooling of H2, but both have their own very unique challenges, and do require quite a lot of additional structure and therefore weight. While H2 will probably happen for short to medium range aircraft, long haul aircraft will have a much harder time to get there and synthetic fuels, while extremely expensive right now, could be the possible solution.
One major advantages of putting the fuel in the fuselage, vs the wings, is that the wings can become *much* less heavy, and also quite a bit thinner, since they are no longer carrying the weight of the fuel, significantly improving the efficiency of the aircraft both by weight and air friction. Retrofitting existing jet aircraft as described in this video does not give you this advantage, but if this plan works, the *next* generation of hydrogen aircraft are 100% certain to take advantage of this.
Put the electrolyser on board the plane, then produce hydrogen on demand from stored water tanks, no high pressure h Hy tanks, the oxygen split can be used for combustion, with pure oxygen there's no nox emissions, which come from combusting with oxygen from the atmosphere. But then you need a generator for the electrolyser, so yea. Scram jet tech is the best bet here, no hydrogen production required
Electrofuels are the best option for aeroplanes. Electrolysis of water for hydrogen and carbon capture from air creates synthetic hyfdrocarbon fuels. Batteries are too heavy for an aircraft and hydrogen is too voluminus.
@Olaf Willocx This scenario is envisioning a future world with abundant clean energy, probably mostly from solar. The question then becomes how to make aviation a net-zero activity.
@@grahamstevenson1740 I believe the fuel cell option to electric motor is better for the environment as any burning creates nitrous oxide in the atmosphere.
@@joeljong931 Oxides of nitrogen are not a seriously huge concern. Doing ANYTHING has undesirable side-effects. There are plenty of issues with EVERY technology. To make an omelette you have to break eggs as the saying goes.
1:46 vs 5:52 this is why the world doesn't jump when "smart people" say this is the best solution. Its filled with complications and nether or best. Each have their own place in the real world.
My main question is aren't propeller planes much louder than turbine jet engines? I can see that being much more bothersome on long haul flights, if the fuel cell engines become viable for larger planes.
@@jonathanodude6660 Even so, the noise generated by a propeller isn't just the engine, it's the propeller blades cutting through the air at very high speed. As far as I understand, that sound is much louder than engine noise. That's why e-vtol aircraft and drones that are battery powered are still very noisy.
This slow and delayed process might sound like a bad thing, but it might actually be just what clean fuel needs to flourish: more time for the dinosaurs to adapt their assets and businesses so they can be part of the change, instead of hindering it out of fear of more competition.
It will take a very long time to put a whole fleet on hydrogen. The best thing to do is use fuel cells as a scaffold. Solid oxide fuel cells and electric propulsion are the best way to start. You can use the same fuels to start with, they are 60% efficient to start with, and you can increase your range. Right now, you could go straight to hydrogen, but there are a lot of hurdles and the hydrogen infrastructure is not in place yet. Your best bet is to give airlines some thing that doesn’t change anything on the ground, saves them money, and is easy to implement
If they apply themselves to it I am sure they can make it viable. Problem is if richest 1% care enough for the health of the planet, which they should as their wealth is generated here, to accelerate the R&D required.
Wait. So the first guy said the beautiful thing about hydrogen is that the energy density is better than jetfuel. The second guy said the bad thing about hydrogen is that the energy density is 3 times lower than jetfuel so you can't store it in the wings like regular fuel...... 😅
The problem is pressure. Hydrogen gas has to be pressurized making unstablilities that need special transports and specialized tanks that have to be changed every years because of the high pressure changes.. While gas is controlled. Also, jet fuel is highly oxygen enriched fuel. Is this feasible. Yes. But not to the scale they want yet. They still have a huge weight problem to overcome.
44 years ago i was at an airline selection board. Had to stay overnight. On tv that evening in their lounge was a Horizon UK tv science show about hydrogen powered aircraft. Where are they? Problem then was most of the cabin would have to be the pressure vessel.
Hydrogen based air travel is safe until the follies of Hindenburg blimp are not repeated in its design and manufacturing stages by aviation corporates.
Take the hydrogen you made with renewable energy and react it with CO2 to make methanol. Much easier to store and handle at room temperature and ambient pressure and it should work well in existing turboprops and jets, just with a bit less range since it is less energy dense than kerosene.
HYSR SunHydrogen has been working on this for years and years . Based in California and multiple university scientists are working with multiple engineering companies.
*ZeroAvia, has announced a development collaboration with the Indian state-owned aerospace & defence company Hindustan Aeronautics Ltd (HAL) for a hydrogen-electric powertrain capable of flying the 19 seat Dornier 228 aircraft up to 500 NM, Nov '21 report suggests.* HAL intends to work with ZeroAvia to develop a Supplemental Type Certificate (STC) to allow retrofit of existing airframes for both Indian military and worldwide operators. HAL also intends to continue to build new aircraft with additional FAA approval, designated Hindustan-228, creating the opportunity to incorporate ZeroAvia's ZA600 zero-emission engines. Additionally, HAL and ZeroAvia engineers will integrate ZeroAvia's ZA600 hydrogen-electric powertrain into the Dornier 228 airframe. ZeroAvia will work closely with HAL and aircraft regulators during this project to ensure that aircraft meets both safety and operational requirements. So there might be actual serious work going on here, given they have own Govt contract.
it will be decades , if ever... The wattage output needed ( assuming this is gonna be fuel cell electric driving a shaft ) is mind bending .. youre talking 8.9Megawatt constant per engine for 2-6hrs even on the smaller commuter models like the airbus a220.. The problem with a lot of these premature engineering ideas is scaling , literally and figuratively.
Yeah, huge difference between a regional prop plane and a transcontinental jet. No one is going to want to fly at 250 mph below the weather across the pacific. Practical hydrogen jet propulsion is a must, if it's ever going to replace current tech.
"well balanced"?! Have you read the other comments here, highlighting the *lack* of balance of this fluff piece that doesn't address the many real issues with hydrogen that mean it will probably never power large commercial planes?
Hydrogen infrastructure needs to be in place first. You could generate hydrogen right now, but you would use Power from the wall to generate it and that’s not the way to do it. Hydrogen works best as a means of power storage from renewables. If you have platforms that use solar, wind, and waves, you can separate sea water into hydrogen and oxygen. That way you don’t tax the grid to generating the fuel, and you don’t use already scarce water from the water supply. That way, hydrogen could almost be like natural gas as far as Energy storage from renewables
@@dervakommtvonhinten517 Well, that depends on the application. And for hydrogen as an energy carrier that is actually the limiting factor. Both on the road and even more so in the air.
@@Soordhin well, no. you always measure energy density by weight. how much volume they actually need to store it is irrelevant. you cant give 2 wildly different statements about an absolute (meaning energy density) of a medium within a couple of minutes. that just makes them look like they dont know what they are talking about.
@@dervakommtvonhinten517 Wrong, i'm afraid. Volume cannot be irrelevant when it is limited, and it always is. The same is true for all energy storage by the way, there is always the gravimetric and the volumetric energy density to be considered. Different to density, energy content is only measured in weight. But that is a different thing altogether. As someone working in aviation we usually measure energy content in weight (we take so and so many tons of fuel). But behind that we do know that the real limit is actually the volume of our fuel tanks, although we rarely reach that. Which is why in easier industries like automotive fuel will be actually measured in volume, not energy content (aka weight), like gallons, litres etc, all measures of volume, not weight.
Right. The other half of this story is the production of hydrogen in usable form. It makes no sense to base transportation of any kind on it if the net result isn't a lot more green. So that needs to be sorted as well.
No residual ice crystal är formed arter an airplane powered by hydrogen, if there are no particles for the water vapor to freeze on. The water vapor can remen liquid down to minus 48°C, merge into water droplets and fall towards the Earth. Above 8000 meters altitude, some particles from other combustion ralely reach. With hydrogen engines at higher altitudes, the formation of light ice crystal, which causes the ice crystal roof, which prevents radiation from the Earth and Global warming would be dramaticaly reducera. At low pressure weather, commercial aviation flies at lower altitudes and comes down into the air with particles, then clin combustion does not help to prevent forming light ice crystal.
On a volume basis, however, the situation is reversed; liquid hydrogen has a density of 8 MJ/L whereas gasoline has a density of 32 MJ/L, as shown in the figure comparing energy densities of fuels based on lower heating values.
on 1:50 energy density of hydrogen is 3 times greater than jet fuel but by 5:50 energy density of hydrogen goes back down to be less than jet fuel at least give some context, what are you comparing, fuel cells, liquid gas?
hydrogen planes also need special engines which make the transition harder. this would mean airlines need new planes to transition instead of efuel solutions
If you're talking about hydrogen in a fuel tank of a plane, it's the same risks as jet fuel in a tank. It's not like the plane has a gigantic flammable balloon of hydrogen...
I suspect someone is gonna have to find a practical way to store liquid hydrogen in airplanes ... probably inside some kind of containers that can easily be removed and replaced in airplanes before every take-off. If even that is sufficient.
Even if the cost remains the same due to low maintainence, you will still need to have more aircrafts for the seats that you are removing as those passengers also need to fly! So the company would need to buy more airplanes which in turn becomes harmful for the environment as then you would need to mine more raw materials to bulid those extra aircrafts.
I think he readed badly his script. H2 obtained by electrolysis with renewable energy is more expensive than H2 obtained by steam reforming of natural gas. This is, steam reforming is cheaper than electrolysis even using cheap renewable energy.
No. The byproduct of hydrogen engines is water. You want to talk about real climate change, spraying millions/billion of gallons of water in the atmosphere
Why not replace kerosene with "green" methanol (produced from CO2 and Hydrogen)? Much easier to store than hydrogen, not that different from kerosene and would not produce that much water vapour. This is the direction the cargo ship industry seems to be taking, e. g. Maersk.
I think the Algae fuel approach is still more feasible, Hydrogen leaks out of everything being such a small molecule. Minimal to no adjustment to existing planes needed. Even if the process isn't as efficient as it could be yet, if it's cheap to implement it almost doesn't matter. Imagine Airports with towers of green vats refining sewage into algae fuel running off solar and wind.
Jet engines would require liquified hydrogen--which require extreme cold. The fuel cells powered electric engines are much more workable, but a lot slower. Look at the recent rocket launch, hydrogen leaks delayed the launch for more than 3 months.
The airports take up a great deal of surface area... using thermal solar you could create fuel on sight. The airport becomes the gas station... Literally
Super silly. There is no known way of making a huge vacuum flask to hold that much liquid hydrogen. Or make it strong enough to survive routine flexing, vibration, and hard landings. You're trying to rebuild the Hindenberg. Oh, the humanity.
I don't think they can replace traditional planes for now. They are talking about replacing turboprop planes, whereas 99% of commercial aviation is gas turbine jet engine planes. Until they figure out making jet engine that burns hydrogen, or a jet engine that runs on plasma instead of combusting fuel, I don't think these propeller aircrafts will have any significant impact on aviation.
H2 will inevitably be the energy carrier of the future. There are technical challenges, but when did technical challenges stop progress? Technical advances have driven societies and their economic underpinnings forever. As the saying goes, necessity is the mother of invention.
Storage should be in the middle of the plane, with people seated front and rear, If not plane will loose balance when gas gets empty and about to land.
For anyone confused about the "hydrogen is 3 times as energy dense as jet fuel" vs the "hydrogen is less energy dense than jet fuel" statements made: Hydrogen is more energy dense by WEIGHT but far less energy dense by VOLUME.
The other way round, but yes, volumetric and gravimetric energy density are the issues at hand, and especially volumetric density is a problem for hydrogen.
@@Soordhin thanks, I meant to say "Hydrogen is more than Jet fuel" didn't catch I just wrote jet fuel lol. The original comment is correct now.
@Victory in Truth Yes, it can be compressed. However, even then is the energy per volume still very low.
@Victory in Truth Also, (just adding onto the above reply) Real Engineering has a very fantastic video explaining the problems with hydrogen (including density and storage issues) if interested. Been awhile since I saw it but I remember finding it extremely helpful.
I believe even the gravimetric energy density statement is disingenuous.
As that only holds true if the hydrogen isn't stored in a container. Which seems impractical..
I feel Hydrogen would be a great choice for big tankers and cargo ships. Where weight and space isn't much of a constraint. For airplanes I don't think we will see much of a change in a few decades.
Nuclear power!
@@gradypalfrey7726 There are already nuclear powered ships like aircraft carrier and Russian ice breakers. But we will never see nuclear cargo ships.
1970s USA already had hydrogen fighter planes.
i dont know about the range. but they worked.
it was made just incase US airforce ran out of oil.
there was also a Nuclear powered military planes.
Totally agree. ... but that won't stop people to to build investor-fleecing schemes around some known principles that only worked for a few milliseconds under ideal conditions in a lab - resulting in Sci-Fi videos like the ones from Bloomberg or the other feelgood-eco-tech Gurus... (edit: wording fixed: "conditions" inserted)
Nuclear actually makes the most sense for large ships IMHO. It's done already in submarines, aircraft carriers and Russian icebreakers.
Fluff piece, an executive in the field mixing up energy density and specific energy... Yes hydrogen has more energy per mass than jet fuel. Unless you include the pressure vessel you need for storage, and the loss of cargo space, due to the low density.
Tongue in cheek, maybe they think that using hydrogen will make the plane lighter, after all, the Hindenburg used hydrogen for lift.
But then again, we all know what happened to the Hindenburg
@@AJHyland63 ...The Hindenburg was originally supposed to use Helium, but America refused to give any and it was also against U.S law..
What? As explained above it was volumetric versus gravimetric density - and the comments were made by the journalist.....not the executive(s) plural in this piece. You probably need to pay closer attention!
Yeah i don't see a feasible way of storing hydrogen in a modern plane design efficiently.
Hydrogen pressure vessels need to be cylindrical so they wont pack well in a half a cylinder under the passenger cabin and in the wings like liquid fuel does.
Maybe if you sacrifice a part of the whole fuselage and put a big tank in the middle of the plane that'd work packing wise.
You'd need to put it near the wings or it'd probably unbalance the plane sitting in the back, then it would split the cabin and take up seating and cargo space cutting into the design's revenue making potential
Hydrogen planes are probably a dead end just on storage alone.
@@lief1 youve just described the entire problem with hydrogen on planes. this is why investment is needed, or else they would have started being rolled out by now. you cannot efficiently store hydrogen in a modern plane design. this is known fact. the retrofitting is for testing and proof of concept only. the future is not cutting seats to put tanks at the back of the plane, its reshaping the entire body to accomodate the new fuel system. if it works out cheaper long term, it will be done, especially since theres an impetus to create less damaging technology whether or not it is cheaper anyways due to the risks to our food, water and land thatd be much more expensive.
Another overlooked problem is hydrogen leakage. Hydrogen has a flammability limit as low as 4% and a detonation limit as low as 18%. How do you prevent airplanes from exploding?
It’s not just the fueling structure that’s the reason hydrogen didn’t take of.
There is also the fact that hydrogen is very hard to store because it such a small molecule and will escape almost every container over time.
Second is the very inefficient production of hydrogen.
Third is supply and demand.
„Because we could use hydrogen for everything that doesn’t mean we should use it“
so this "hard to store hydrogen", read on it. hydrogen loss through a plastic or metal container is almost insignificant.
@@leihtory7423 not under high pressure
AND every seal needs to be metal seal because rubberseals don’t work
Thank you, a voice of reason finally! All this hyperbole on hydrogen is complete rubbish. The production, transfer and use of hydrogen is marred with inefficiency, high carbon footprint and unsustainable operating costs. This video is nothing more than media hype
@@pantalome H2 for most transport is a nonsense (maybe for trains in not electrified lines, or ships). H2 for clean heavy industry is really needed. It's amazing how they can remove almost all coal in steel production.
NH3 overcomes a lot of the storage issues as the pressures required to maintain it in a liquid state. NH3 is liquid at 1 bar at -30C and it's -40C ish at 30k feet. It would need insulated tanks and refrigeration at higher temperatures when the engines are not running.
The most practical way to store hydrogen is to react it with carbon dioxide to form a hydrocarbon that is liquid at atmospheric temperature and pressure. The future of aviation is synthetic hydrocarbon jet fuel produced using renewable energy instead of fossil fuel sourced jet fuel.
Zach
Then we are back to CO2 problem..
No, that is not the future. Burning your hypothetical synthetic jet fuel would still produce CO2.
Wrong. Store it as ammonia, much higher round trip efficiency
@@elliotdelacruz390 What problem is that?
Many experiments have been done with H^2 as an aviation fuel. Storage is not the only problem mainly Bleed off thru subduction. But the main problem is Hydrogen embrittlement of engine components.
They arent combusting it in an engine for a fuel cell application though
These would be solved or accounted fot. Embrittlement is a function of water content and temperature along with hydrogen. Storage is getting better. But I'm just observing.. don't know the total EROI.
2:00 I find it quite revealing that he says the energy density of hydrogen is 3 times higher thant that of jet fuel, and doesn't care to mention that the energy density of hydrogen by volume is 6 to 7 times lower than that of jet fuel. Thats a big design problem for hydrogen in Aviation.
@Flame it was. Problem is he didn‘t mention that and also didn‘t made the differentiation. Its cherry picking to deceive people. Either that or He doesn’t really know what hes talking about
@@xDanoss318x at 5:50 they clearly mention that even with a higher density, it does take up much more room.
@@ryanthompson3737 „they“ is a completely different person to whom I was referring to.
I‘m not accusing the maker of this video, I am accusing the actual person that was speaking.
"Hydrogen is the most abundant element in the universe" is also a nice deception.
@@musaran2 The hydrogen in the universe is mostly in stars (e.g. the Sun). And the hydrogen on Earth is part of molecules (e.g. water) and it takes energy to extract it. And the cheapest and most common hydrogen production process emits a lot of greenhouse gas.
Hydrogen is the most abundant element in the Universe (except on Earth), just like nuclear fusion is the most common method of generating power in the Universe (except on Earth).
You opened the video with a skewed truth, and kept going for the rest of it.
An hydrogen powered airplane is impossible to build, because the weight of tanks to store compressed hydrogen are simply too heavy for airborne vehicles.
It is possible to use cryogenic hydrogen for aircrafts, but it become a problem for long haul flights, because of evaporation...
Why can't US just invade Sun to secure hydrogen resource?
@Flame yea, every carbon atom has 6 hydrogen atoms, you just need to split it!
@Flame sure, lets burn some coal to detach this wonedfull green hydrogen from water.
Hydrogen can be synthetically combined with biofuels to make jet fuel and run our present jet planes. Liquid hydrogen can run a jet plane on longer distances than our present plane. All of our fossil fuels are hydrogen, all of our bio system is hydrogen all of the water is hydrogen.
Evaporation can be handled thru carbon nanotechnology and nanotechnology in general
As an elektrical engineer I still ask myself how the replacement should work for planes like the A320-neo.
* 24'000ltr Kerosin (240 MWh) whould need to be replaced by 7200 kg H2 with at least (!) 73'000ltr of volume even when liquified.
* The A320 has about 2700l/h consumption, i.e. 27MW. With an efficacy of e.g. 70% this means about 19MW mechanical power. Replacing that with an electric engine would mean about 172 to weight compared to about 2x2.6 to of the existing engines.
Sorry, I don't get it how that shall be replaced with H2.
you're right. That's why it won't. From a certain plane size you have no way but to directly combust hydrogen. this way, the only inconvenience is the 4 times bigger, heavily isolated and pressure conform tank.
Well that's a big backflip!
1:40 The energy density of hydrogen as fuel is 3 times that of jet fuel...
5:50 the energy density of hydrogen is less then jet fuel...
1:44 - "The energy density of Hydrogen is 3x that of jet fuel"
5:53 - "The energy density of Hydrogen is less than jet fuel"
1:44 is energy density by mass (hydrogen is quite lightweight and planes like lightweight). 5:53 is density by volume, kerosene is a liquid at airplane temperatures, hydrogen not so much. Stored as a gas under high pressure, or a cryogenic liquid, it's never going to be as efficient as wet wings. If looks like bio-kerosene (aka Navy Green Hornet) is a much better idea than this.
He meant volumetric density
I simply wanted to point out the contradiction. They should have specified how impractical it would be to run airplanes on liquid Hydrogen ( 1:44 ). It may have a higher mass density but a lot of energy is required to cool it to liquid form. Storage is also a lot more difficult
There are so many a-380's that are parked by airlines now days that you could pick one up cheaper and test with it,
It's three times as dense, yet it's less dense? Man, don't use energy density for energy/mass, only for energy/volume! Energy/mass is called specific energy!
Great reporting, eh?
Well, you are partially correct. The actual commercial aircraft will use a hybrid fuel of 20% hydrogen together with 80% ammonia. Ammonia is a much better container of hydrogen than hydrogen itself, but its combustion is slow so it requires something else like hydrogen to be added into the mix to speed up the combustion process.
what is the efficiency of combusting ammonia? i cant imagine it would be worth the haber bosch process.
@@jonathanodude6660 there are lower energy ammonia production methods being developed. If using ammonia is the only way to get long range flight then it doesn't matter too much how efficient it is. The only other non fossil alternative is synthetic fuel, which requires capturing CO2 from the atmosphere, which is extremely expensive. Nitrogen is enormously easier to obtain since it is most of the atmosphere.
@@jonathanodude6660
Canadian 123 is just ignorant.
The combustion energy for hydrogen is 39,5 KWh/ but 1 kg liquid hydrogen is 14 liter. How to fit it in an airplan
The combustion energy for ammonia is 5,2 KWh/kg only.
And the energy demand for the Haber Bosch process to produce ammonia is 10 KWh/kg NH3. So, where is the benefit of ammonia. Only a fool would tell us anything about the benefit of ammonia.
@@wilfriedschuler3796 I knew the numbers wouldn’t make sense. Combusting fuels we make ourselves only provide benefits if we make the fuel using excess renewable energy. If we have to burn fossil fuels to provide the energy required to make them, we might as well just keep using the fossil fuel. Doing that would use less energy overall.
@@adrianthoroughgood1191 think about what you’re saying. We have to make the ammonia. It does matter how efficient it is. We don’t make fossil fuels.
You’re saying that if we burn 100 GWh worth of natural gas to make some ammonia, then we get 20 GWh back from burning the ammonia, it doesn’t matter because in the future we hope ammonia production will get less energy intensive? Why not just use 20 GWh of natural gas and skip the ammonia which wastes 80 GWh, then we can do it 5x more with the same amount of energy?
Also synthetic fuel does not require carbon capture. There are lots of carbon sources on the planet. Nitrogen is easy to obtain in its gaseous form, but it’s extremely unreactive and so using it to produce anything is difficult, expensive, energy intensive and requires toxic heavy metals.
The solution is not hydrogen. The solution is to go nuclear. Nuclear powered passenger planes are what we need.
You wanna know how you can immediately identify articles that are overhyping technology stories? When they use tentative language like MIGHT BE or COULD or MAY or any other such synonym. I speak from experience of 20 years of reading/watching stories like this. Stories about tech that are written by people who clearly have no idea about technology.
"energy density of hydrogen is 3x jet fuel"
"the energy density of hydrogen is less than jet fuel"
He meant volumetric density
1:44 is energy density by mass (hydrogen is quite lightweight and planes like lightweight). 5:53 is density by volume, kerosene is a liquid at airplane temperatures, hydrogen not so much. Stored as a gas under high pressure, or a cryogenic liquid, it's never going to be as efficient as wet wings. If looks like bio-kerosene (aka Navy Green Hornet) is a much better idea than this.
@@takudzwamashamba7453 well obviously. If he meant per unit mass then be specific.
Both statements are true. Quite often people want to make a specific point and, disingenuously, omit the required qualifier (volumetric or gravimetric) in regards to energy density.
H2 has the highest gravimetric energy density, but one of the lowest volumetric energy densities. While planes do care about weight, it is not nearly as much an issue as is volume, since volume translates directly into the required size and therefore drag of the airplane. Of course that can be somewhat alleviated by going into high pressurization and/or supercooling of H2, but both have their own very unique challenges, and do require quite a lot of additional structure and therefore weight.
While H2 will probably happen for short to medium range aircraft, long haul aircraft will have a much harder time to get there and synthetic fuels, while extremely expensive right now, could be the possible solution.
@@rsaunders57 BUT the container is anything but lightweight ! BAD for planes.
One major advantages of putting the fuel in the fuselage, vs the wings, is that the wings can become *much* less heavy, and also quite a bit thinner, since they are no longer carrying the weight of the fuel, significantly improving the efficiency of the aircraft both by weight and air friction. Retrofitting existing jet aircraft as described in this video does not give you this advantage, but if this plan works, the *next* generation of hydrogen aircraft are 100% certain to take advantage of this.
I don’t see how any of this is making actual sense yet
Put the electrolyser on board the plane, then produce hydrogen on demand from stored water tanks, no high pressure h
Hy tanks, the oxygen split can be used for combustion, with pure oxygen there's no nox emissions, which come from combusting with oxygen from the atmosphere. But then you need a generator for the electrolyser, so yea. Scram jet tech is the best bet here, no hydrogen production required
Electrolysis requires more energy put in than you get out from the hydrogen
Electrofuels are the best option for aeroplanes. Electrolysis of water for hydrogen and carbon capture from air creates synthetic hyfdrocarbon fuels.
Batteries are too heavy for an aircraft and hydrogen is too voluminus.
@Olaf Willocx This scenario is envisioning a future world with abundant clean energy, probably mostly from solar. The question then becomes how to make aviation a net-zero activity.
Carbon capture is still wishful thinking, just use ammonia, much easier
@Olaf Willocx The best answer is to burn the hydrogen in the engine and avoid using electricity.
@@grahamstevenson1740 I believe the fuel cell option to electric motor is better for the environment as any burning creates nitrous oxide in the atmosphere.
@@joeljong931 Oxides of nitrogen are not a seriously huge concern. Doing ANYTHING has undesirable side-effects. There are plenty of issues with EVERY technology. To make an omelette you have to break eggs as the saying goes.
If you find any publicly traded companies who specialise in hydrogen fuel cells, they’re the easiest short you’ll ever find :)
So which is it? Is hydrogen denser or not than jet fuel? 1:48 5:55
1:46 vs 5:52 this is why the world doesn't jump when "smart people" say this is the best solution. Its filled with complications and nether or best. Each have their own place in the real world.
It's classic populist misleading oversimplification.
My main question is aren't propeller planes much louder than turbine jet engines? I can see that being much more bothersome on long haul flights, if the fuel cell engines become viable for larger planes.
it would be an electric motor though. its not like you have an engine powering a propeller. think more personal fans and windmills than cars.
@@jonathanodude6660 Even so, the noise generated by a propeller isn't just the engine, it's the propeller blades cutting through the air at very high speed. As far as I understand, that sound is much louder than engine noise. That's why e-vtol aircraft and drones that are battery powered are still very noisy.
This slow and delayed process might sound like a bad thing, but it might actually be just what clean fuel needs to flourish: more time for the dinosaurs to adapt their assets and businesses so they can be part of the change, instead of hindering it out of fear of more competition.
They really should specify "by weight" or "by volume" when they say hydrogen is more/less energy dense than gasoline
It will take a very long time to put a whole fleet on hydrogen.
The best thing to do is use fuel cells as a scaffold.
Solid oxide fuel cells and electric propulsion are the best way to start. You can use the same fuels to start with, they are 60% efficient to start with, and you can increase your range.
Right now, you could go straight to hydrogen, but there are a lot of hurdles and the hydrogen infrastructure is not in place yet.
Your best bet is to give airlines some thing that doesn’t change anything on the ground, saves them money, and is easy to implement
If they apply themselves to it I am sure they can make it viable. Problem is if richest 1% care enough for the health of the planet, which they should as their wealth is generated here, to accelerate the R&D required.
Remove able drop tanks. One on each wing. Purpose built exterior fuel tanks that can be quickly replaces upon arrival
Wait. So the first guy said the beautiful thing about hydrogen is that the energy density is better than jetfuel. The second guy said the bad thing about hydrogen is that the energy density is 3 times lower than jetfuel so you can't store it in the wings like regular fuel...... 😅
Energy density vs physical density
The problem is pressure. Hydrogen gas has to be pressurized making unstablilities that need special transports and specialized tanks that have to be changed every years because of the high pressure changes.. While gas is controlled. Also, jet fuel is highly oxygen enriched fuel. Is this feasible. Yes. But not to the scale they want yet. They still have a huge weight problem to overcome.
You need to talk about the world's farm machinery sir
I was literally looking for such a video this morning, thanks!
There was a big hype about H2 like 15-20 years ago, and it fizzled away. It might again.
44 years ago i was at an airline selection board. Had to stay overnight. On tv that evening in their lounge was a Horizon UK tv science show about hydrogen powered aircraft. Where are they? Problem then was most of the cabin would have to be the pressure vessel.
Hydrogen based air travel is safe until the follies of Hindenburg blimp are not repeated in its design and manufacturing stages by aviation corporates.
Thank you for sharing! Maybe Boeing India can accomplish it!
Take the hydrogen you made with renewable energy and react it with CO2 to make methanol. Much easier to store and handle at room temperature and ambient pressure and it should work well in existing turboprops and jets, just with a bit less range since it is less energy dense than kerosene.
I should definitely invest more in methanol companies.
Add some CH2 and I’m in
@@thepandaahbear9025 Nerd! 🙂
Better than making it from corn (or is that ethanol?🤔 - still alcohol tho).
HYSR SunHydrogen has been working on this for years and years . Based in California and multiple university scientists are working with multiple engineering companies.
*ZeroAvia, has announced a development collaboration with the Indian state-owned aerospace & defence company Hindustan Aeronautics Ltd (HAL) for a hydrogen-electric powertrain capable of flying the 19 seat Dornier 228 aircraft up to 500 NM, Nov '21 report suggests.*
HAL intends to work with ZeroAvia to develop a Supplemental Type Certificate (STC) to allow retrofit of existing airframes for both Indian military and worldwide operators. HAL also intends to continue to build new aircraft with additional FAA approval, designated Hindustan-228, creating the opportunity to incorporate ZeroAvia's ZA600 zero-emission engines. Additionally, HAL and ZeroAvia engineers will integrate ZeroAvia's ZA600 hydrogen-electric powertrain into the Dornier 228 airframe. ZeroAvia will work closely with HAL and aircraft regulators during this project to ensure that aircraft meets both safety and operational requirements.
So there might be actual serious work going on here, given they have own Govt contract.
hydrogen in the atmosphere is 10X worse than co2 emissions..
👍👍👍
Innovation always wins not a way around. This feels like a way around
it will be decades , if ever... The wattage output needed ( assuming this is gonna be fuel cell electric driving a shaft ) is mind bending .. youre talking 8.9Megawatt constant per engine for 2-6hrs even on the smaller commuter models like the airbus a220.. The problem with a lot of these premature engineering ideas is scaling , literally and figuratively.
Yeah, huge difference between a regional prop plane and a transcontinental jet. No one is going to want to fly at 250 mph below the weather across the pacific. Practical hydrogen jet propulsion is a must, if it's ever going to replace current tech.
Credit to you for these engrossing, educational and well balanced videos
"well balanced"?! Have you read the other comments here, highlighting the *lack* of balance of this fluff piece that doesn't address the many real issues with hydrogen that mean it will probably never power large commercial planes?
Just because some small corner company is doing it doesn’t mean it’ll happen
Hydrogen infrastructure needs to be in place first.
You could generate hydrogen right now, but you would use Power from the wall to generate it and that’s not the way to do it.
Hydrogen works best as a means of power storage from renewables. If you have platforms that use solar, wind, and waves, you can separate sea water into hydrogen and oxygen.
That way you don’t tax the grid to generating the fuel, and you don’t use already scarce water from the water supply.
That way, hydrogen could almost be like natural gas as far as Energy storage from renewables
Energy density of hydrogen is less than jet fuel 5:56
the energy density of hydrogen as fuel is 3 times better than jet fuel 1:50
SO WHICH IS IT??????
Both. Volumetric energy density of hydrogen is very low, energy density by weight (gravimetric) is extremely high.
@@Soordhin NOBODY measures energy density of a gas by volume.....
@@dervakommtvonhinten517 Well, that depends on the application. And for hydrogen as an energy carrier that is actually the limiting factor. Both on the road and even more so in the air.
@@Soordhin well, no. you always measure energy density by weight. how much volume they actually need to store it is irrelevant. you cant give 2 wildly different statements about an absolute (meaning energy density) of a medium within a couple of minutes. that just makes them look like they dont know what they are talking about.
@@dervakommtvonhinten517 Wrong, i'm afraid. Volume cannot be irrelevant when it is limited, and it always is.
The same is true for all energy storage by the way, there is always the gravimetric and the volumetric energy density to be considered.
Different to density, energy content is only measured in weight. But that is a different thing altogether. As someone working in aviation we usually measure energy content in weight (we take so and so many tons of fuel). But behind that we do know that the real limit is actually the volume of our fuel tanks, although we rarely reach that. Which is why in easier industries like automotive fuel will be actually measured in volume, not energy content (aka weight), like gallons, litres etc, all measures of volume, not weight.
I'm all for eletric motors, but turbines are very simple in moving parts.
There are less moving parts in an electric motor than in a gas turbine.
Hydrogen has many drawbacks as well.
Fun fact: most hydrogen isn’t even green.
Right. The other half of this story is the production of hydrogen in usable form. It makes no sense to base transportation of any kind on it if the net result isn't a lot more green. So that needs to be sorted as well.
No residual ice crystal är formed arter an airplane powered by hydrogen, if there are no particles for the water vapor to freeze on. The water vapor can remen liquid down to minus 48°C, merge into water droplets and fall towards the Earth. Above 8000 meters altitude, some particles from other combustion ralely reach. With hydrogen engines at higher altitudes, the formation of light ice crystal, which causes the ice crystal roof, which prevents radiation from the Earth and Global warming would be dramaticaly reducera. At low pressure weather, commercial aviation flies at lower altitudes and comes down into the air with particles, then clin combustion does not help to prevent forming light ice crystal.
1:42 contradicts 5:53 The difference is in considering the storage tank weight
"That's technical commercial."
OK
Russian tupolev 56 built in 1984 ran on hydrogen fuel and did 112 successful flights and never met with any accidents...
Nice video.
You'll be increasing the humidity and airborne water in the atmosphere including clouds
AGREED and supply and distribution a lot simpler than for cars.
On a volume basis, however, the situation is reversed; liquid hydrogen has a density of 8 MJ/L whereas gasoline has a density of 32 MJ/L, as shown in the figure comparing energy densities of fuels based on lower heating values.
Burning hydrogen...They just made a rocket plane!
Have we forgotten what happened to the Hindenburg?
on 1:50 energy density of hydrogen is 3 times greater than jet fuel
but by 5:50 energy density of hydrogen goes back down to be less than jet fuel
at least give some context, what are you comparing, fuel cells, liquid gas?
hydrogen planes also need special engines which make the transition harder. this would mean airlines need new planes to transition instead of efuel solutions
0:58,... I'm sorry, unfortunately in combustion chamber it also triggered N2 to react with O2 producing NOx....
Hindenberg? Didn't we already do this?
If you're talking about hydrogen in a fuel tank of a plane, it's the same risks as jet fuel in a tank. It's not like the plane has a gigantic flammable balloon of hydrogen...
The right design will be to design an electric plane from the ground up.With structural battery and efficient solar panels it can be done.
The unknown effects of water-vapor emissions (contrails) at altitudes most efficient for air-transport is an issue . . .
By volume, the largest quantity of greenhouse gas is . . . water vapor.
It's surprising Airbus uses a high operating cost A380 to accommodate a 400kg H2 fuel tank.
Great news for me. I am excited 💖
How amusing that we still use an incandescent light bulb to demonstrate something is generating / using electrical energy :)
I suspect someone is gonna have to find a practical way to store liquid hydrogen in airplanes ... probably inside some kind of containers that can easily be removed and replaced in airplanes before every take-off. If even that is sufficient.
Even if the cost remains the same due to low maintainence, you will still need to have more aircrafts for the seats that you are removing as those passengers also need to fly! So the company would need to buy more airplanes which in turn becomes harmful for the environment as then you would need to mine more raw materials to bulid those extra aircrafts.
Another error is "renewables are more expensive" which is wrong and must have been pushed by oil industry advertisers
I think he readed badly his script. H2 obtained by electrolysis with renewable energy is more expensive than H2 obtained by steam reforming of natural gas. This is, steam reforming is cheaper than electrolysis even using cheap renewable energy.
No. The byproduct of hydrogen engines is water. You want to talk about real climate change, spraying millions/billion of gallons of water in the atmosphere
News flash, unless jet engines run on high purity coal... They already spew majority of their emissions as water
Val fails to mention that a hydrogen-powered aircraft will effectively be a flying fuel tank.
Actually, there are byproducts besides water, because of inefficient combustion.
Why not replace kerosene with "green" methanol (produced from CO2 and Hydrogen)? Much easier to store than hydrogen, not that different from kerosene and would not produce that much water vapour. This is the direction the cargo ship industry seems to be taking, e. g. Maersk.
Could we theoretically use that water if its used in large scale in order to relieve stress from our ground water levels?
Energy sector moves hydrogen around via ammonia as a carrier through pipelines and trucks.
The most abundant element isn’t hydrogen as stated in this video. It’s carbon.
Not everything can go green. Unless you want to donate your body to the worms.
Can't store in wings, that sucks.
Hydrogen is most abundant element in the universe, all we have to do is extract it from the Sun!
I think the Algae fuel approach is still more feasible, Hydrogen leaks out of everything being such a small molecule. Minimal to no adjustment to existing planes needed. Even if the process isn't as efficient as it could be yet, if it's cheap to implement it almost doesn't matter. Imagine Airports with towers of green vats refining sewage into algae fuel running off solar and wind.
Getting back to Hindenburg era
Jet engines would require liquified hydrogen--which require extreme cold. The fuel cells powered electric engines are much more workable, but a lot slower. Look at the recent rocket launch, hydrogen leaks delayed the launch for more than 3 months.
The airports take up a great deal of surface area... using thermal solar you could create fuel on sight.
The airport becomes the gas station... Literally
That statement that only water vapor is produced in this reaction is wrong. There’s also NOx emissions.
Super silly. There is no known way of making a huge vacuum flask to hold that much liquid hydrogen. Or make it strong enough to survive routine flexing, vibration, and hard landings. You're trying to rebuild the Hindenberg. Oh, the humanity.
it reject water in high atmosphere which is > as effet de serre than co2
heard all this in the 90s....
I don't think they can replace traditional planes for now. They are talking about replacing turboprop planes, whereas 99% of commercial aviation is gas turbine jet engine planes. Until they figure out making jet engine that burns hydrogen, or a jet engine that runs on plasma instead of combusting fuel, I don't think these propeller aircrafts will have any significant impact on aviation.
Whats the water like that comes out of producing hydrogen? is it drinkable?
Yes. You need to add minerals to be healthy.
makes perfect sense
so where do you put your cargo then?
Can you use mix, half A fuel with half hydrogen = hybrid fuel..? At least reduce bad air by half.
I am beyond skeptical about this
H2 will inevitably be the energy carrier of the future. There are technical challenges, but when did technical challenges stop progress? Technical advances have driven societies and their economic underpinnings forever. As the saying goes, necessity is the mother of invention.
Storage should be in the middle of the plane, with people seated front and rear, If not plane will loose balance when gas gets empty and about to land.