you can use the hydrogen an arbitrarily large number of times once you get it there, and the amount of water needed is so small that this is not a major part of the cost of a grid-scale storage system system even if you have to truck it in, which you don't because even deserts have groundwater
please do the math instead of posting random bullshit without respect to whether it's true or not
specifically hydrogen is 142 MJ/kg
https://en.m.wikipedia.org/wiki/Energy_density
and is 1/9 of water by mass, so each kg of water you drill, truck in, or collect from cisterns can store 15.8 MJ as hydrogen. a square meter of 21% efficient pv panel produces 210 watts nameplate, or 52 watts derating for the 25% capacity factor typical for deserts. that is 4.5 MJ per day. the water needed to store the panel's daily production weighs much less than the panel itself and is therefore much cheaper to truck in
obviously it would be stupid to truck it back out again unless you decided to do your grid-scale storage somewhere else
please do the math instead of posting random bullshit without respect to whether it's true or not
specifically hydrogen is 142 MJ/kg https://en.m.wikipedia.org/wiki/Energy_density and is 1/9 of water by mass, so each kg of water you drill, truck in, or collect from cisterns can store 15.8 MJ as hydrogen. a square meter of 21% efficient pv panel produces 210 watts nameplate, or 52 watts derating for the 25% capacity factor typical for deserts. that is 4.5 MJ per day. the water needed to store the panel's daily production weighs much less than the panel itself and is therefore much cheaper to truck in
obviously it would be stupid to truck it back out again unless you decided to do your grid-scale storage somewhere else