How efficient is making hydrogen? If you don’t need a huge facility, it might be easier to just store it that way, so you don’t need giant lakes everywhere.
Less efficient than pumped hydro. Appears to be about 40% for green hydrogen in the round trip vs 80% for pumped hydro with a quick google search.
I am curious what’s involved in the “round trip”? Do you mean to fuel other machines directly with hydrogen?
directly storing electricity as a chemical battery system is likely going to be more efficient (way more optimized and generally a lot simpler) and something like thermal energy storage (really, really simple, and very, very effective, plus pretty cheap, there just isn’t much accessible tech out there at the moment, though it suffers from the same conversion problem, it’s certainly a lot simpler than hydrogen.)
ok so funny problem, storing hydrogen is currently the next nobel prize. And uh, generating it while theoretically easy, is very power hungry. (less of a problem here though tbf with cheap solar power)
Also producing power from hydrogen is more complicated than you would think. You could do a hydrogen fuel cell, or possibly burn it directly, but since hydrogen tends to sort be very spicy, it’s a little hard sometimes.