How are you calculating that entire reservoir would boil? It's filled with 8B m^3 of water. I couldn't find the formulas to calculate this myself, but given Tu

How are you calculating that entire reservoir would boil? It's filled with 8B m^3 of water. I couldn't find the formulas to calculate this myself, but given Tuna-Fish's comment above that it's enough to boil a kiloton of water (1000 m^3) ever hour that's 1K/8B =~ 0.00001%. So it's going to be more on the order of dropping a single drop of boiling water into a backyard pool every hour, is it not? I.e. something that wouldn't change the overall temperature of the reservoir to any significant degree. This is all assuming that you'd have to use the energy to heat the reservoir itself, you could just as easily use it to pump out some water and boil it until it evaporates, not impacting the temperature of the reservoir at all, just emitting a lot of steam into the air.