[d33lio]

This is precisely the literary slight of hand I was talking about! Similar to Musk's hilarious dismissal of hydrogen technology. Hydrogen will obviously in time become the ideal source of energy for electric aircraft and electric long haul trucks.

[tuatoru]

"Obviously" is shorthand for "I want you to believe this but I don't have evidence for it, and I can't see how to validate it".

Used a lot in mathematics, substituting "proof" for "evidence".

[LockAndLol]

Has hydrogen storage been solved? How big would a hydrogen tank have to be to power a plane for more than an hour? And what is the conversion rate of hydrogen to electricity?

[rsfern]

Hydrogen storage is definitely not a solved problem. It was a hot funding topic for the US DOE a few years ago, but sufficient energy density and operating pressures are super challenging targets to hit.

Efficiency depends on fuel cell type and operating conditions and such, but I think it’s generally pretty high for the useful life of the catalyst material. (The catalyst is another materials challenge itself, since I think most of the good materials are super expensive like Pt/Pd alloys, and they’re vulnerable to carbon monoxide poisoning)

Edit: this DOE program page has some good detailed discussion of the current status, including on compressed liquid/gas storage systems, which I’m not as familiar with: https://www.energy.gov/eere/fuelcells/hydrogen-storage-curre...