rickair7777

Normal jet engines powered by hydrogen would work fine.

The challenges (off the top of my head)...

1. H2 has VERY good specific energy (over twice that of Jet A), so it's light-weight. But if you use liquid H2, the energy density is about FOUR times that of Jet A... so you'd need a LOT more tank volume. While the fuel itself is much lighter, the weight and form drag of the extra tank volume will cost you. I assume airbus has done the math and come up with a plan... that blended wing-body thing would have a lot of internal volume.

2. Liquid H2 is difficult and dangerous to handle. Jet A is not explosive if spilled, liquid H2 is... very. It's also cryogenic, so everything in the storage and handling system will need to be "special" ($$$$$$$$$). Apollo used kerosene instead for these reasons, but space shuttle used liquid H2. The Saturn-V had a better safety record. Rampers gonna need a pay raise...

3. Compressed H2 would require very strong (ie heavy) tanks, and the volume would be impractical at any reasonable pressure (about twice the volume of liquid H2, eight times that of Jet A).

4. Lastly, there's some scientific concern that dumping a lot of water vapor into the upper atmosphere would have it's own greenhouse effect... and burning H2 has only one combustion product. Not sure what airbus is thinking with regards to that, maybe they just consider the last ditch excuse of the eco-freaks to justify "airplanes bad, your socialist masters should make you stay home".

Also you make H2 by splitting water molecules with electricity, so you'd need your grid power to be green, or you're just moving the carbon emissions from the sky to ground (maybe that's actually better for the climate issues?). The good news though is that you might not have to transport H2 to the airport... you can probably make it on-site with tap water and grid power (lots of both). And you get more free O2 than you could ever use too.