[pfdietz]

For static applications, hydrogen can be easily stored underground. Energy is used to compress it, but that energy can be recovered by running it through an expander (and if the compression/expansion is done in stages to approximate isothermal compression, the round trip efficiency of this can be high.)

[foxyv]

That's really neat! I've mostly seen explanations about Hydrogen as a vehicle fuel so I've never stumbled on cavern storage. It makes sense to use isothermal compression. Especially if you can recover the energy from decompressing the hydrogen using a turbo expander which would be obscenely difficult on a vehicle.

[_hypx]

Why would it be difficult in a car? It is the same principle as a compressed air car: https://en.wikipedia.org/wiki/Compressed-air_car

[foxyv]

A turboexpander in a car would add an obscene amount of cost to an already expensive fuel cell vehicle. Also, it would be a fire and explosion hazard requiring a ton of maintenance.

[_hypx]

That sounds completely unsubstantiated. Nothing involved here is that complicated or expensive. In fact, the whole thing should cost less than a comparable BEV given how little raw material you need. And if properly designed, it should be perfectly safe.