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Environment & Energy

OKIsItJustMe

(21,612 posts)

1. The biggest challenge for ZeroAvia is the volume needed for hydrogen fuel

Reply to Caribbeans (Original post)

Fri Jul 25, 2025, 09:19 PM

Jul 25

The classic example (in my mind) is the Saturn V. The top stages of the Saturn V were powered by hydrogen/oxygen. Electricity was provided by fuel cells, which also produced fresh water as a byproduct. Hydrogen was chosen, primarily for its energy/mass ratio.

However, the 1st stage of the Saturn V used RP-1/oxygen. (RP-1 is essentially highly refined kerosene.) RP-1 was used for the first stage because of its high energy/volume ratio.

If you go back to the 1970’s NOVA documentary, The Invisible Flame, a pair of aircraft engineers are predicting that hydrogen will be the future of commercial aviation. They explain how they propose to modify jetliners to accommodate hydrogen fuel.

(Skip forward to 31:31.)

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Highlight:

American Airlines Bets Big on Zero-Emission Future with ZeroAvia Hydrogen-Electric Engine Deal [View all] Caribbeans Jul 25 OP

The biggest challenge for ZeroAvia is the volume needed for hydrogen fuel OKIsItJustMe Jul 25 #1

Also where do you get the hydrogen? 4th Jul 26 #2

Well, the plan is to use electrolysis to produce it from water OKIsItJustMe Jul 26 #4

Wow, that's some seriously primo AI "art" at the top of the article!! hatrack Jul 26 #3