[Zeta_Function]

You can do the same thing with compressed gas as well, or really anything. Gas and fluid do make the most sense in terms of directly driving generator turbines though. The only issue with gas is thst you have to deal with thermal effects from expansion and compression.

[kumarvvr]

Using compressed gas for energy storage has a lower cycle efficiency. Compressing heats up the gas. Heat has to be stored and used when decompressing, else a significant portion of energy is lost and the cycle efficiency is dragged into the low 50% range, or even less.

[Zeta_Function]

True, I did mention thermal effects, but it’s also something you can do in a place like Cali, Nevada, Riyadh, etc Without wasting precious water. Other options include giving up on the idea of these systems and going for giant Vanadium flow batteries or something similar.

[kumarvvr]

Vanadium flow batteries are an extremely interesting concept. But with lower power densities, they seem to be more suitable for use in a local community, rather than individual homes or grid scale plants.