The study authors found bitcoin mining involved hydroelectric power using water, and in other types of powerplants, but also water being used locally as coolant. They suggest it is being lost due to evaporation. Do bitcoin miners use evaporative cooling? I’m hoping you know, but I’m not sure that they do, because computer watercooling tends to be a closed loop, or a loop with a sealed reservoir. If not, the phase-change itself would be useful for cooling, like in a heat-pipe, just condensing at the other end.

“This cooling water is evaporated and not available to be reused”, well…it is vapourized. It isn’t destroyed. I think the study authors will find that it sometimes falls back out of the sky.

The article seems to conflate “a single bitcoin transaction” with the mining of a single bitcoin. As far as I know, a single bitcoin transaction is computationally trivial, when mining one intentionally isn’t.