Originally Posted by
tdracer
The problem with hydrogen as an aircraft fuel is - and always will be - storing it on the aircraft. While H2 is very light for it's energy density, it's not dense.
Exactly. Airbus hyped a hypothetical hydrogen-powered Mach 4.5 "ultrarapid transport" back in 2015.
Roughly the dimensions of Concorde - but with seating for only 20. The aft
75% of the fuselage was taken up by the liquid H2 tank (and a small O2 tank for a "rocket acceleration/climb phase" in addition to air-breathing turbojet (TO/LNDG) and ramjet (drift-up cruise) flight phases).
I like the idea of H2 fuel, for its flexibility - fuel-cell electric, hot-combustion thrust - as well as no carbon involved. But outside of blimps, it sadly doesn't offer much for aviation anytime soon.