[feadog]

Hydrogen powered cargo ships have already been made as well. However, I'm not sure if hydrogen generation on board ships has been explored yet. Who knows... it may be possible for ships to run without ever needing to refuel if generation is done on board.

Sorry. Go back and study thermodynamics again. If you have the energy to generate hydrogen, you might as well use that energy to move the ship. You're always going to spend more energy generating the hydrogen than you will get back burning it or combining it in a fuel cell. The one exception is if you start from just the right feedstock to generate the hydrogen from, like some hydrocarbon. The leading candidate now is natural gas. However, in that case, the byproduct is CO2 -- so what's the point?

Or, maybe you were thinking of hydrogen as energy storage? Batteries are far better than hydrogen as far as that goes.

[vamur]

Energy generation is not a problem, there is nuclear, sun, wind. Energy storage is. Currently, hydrogen should be a better option for energy storage as it is cheaper than the expensive and explosive lithium-ion batteries. Never mind that lithium-ion loses its capacity on every cycle and requires rare minerals.

[renesd]

Yeah, you're probably right... generation on board ship doesn't make much sense. Unless the ship is stopped for some time I guess.

Storage for hydrogen can be really large, in the TWh size. Because they can use natural gas storage tanks. There's nothing that big for batteries. The big Tesla solar installation on that Samoa island was six megawatt hours, with 60 battery packs.