On a large ship, space isn’t at a huge premium. For a truck it’s...

On a large ship, space isn’t at a huge premium. For a truck it’s more of a challenge and an airplane even more. But high pressure, cryogenic or bonded with something else, eg as ammonia, seem to be the options for hydrogen transport.

I’m no expert, but I think of hydrogen as the electrolyte in a flow battery. Flow batteries typically have a higher Wh / W ratio than conventional batteries because the energy is stored separate from the fixed electrode. That gives them an advantage for long duration storage. Ammonia’s energy density per kg is around 10 times greater than a typical lithium ion battery.

Any other HC contributors please feel free to extend and/or correct my understanding.