It’s solar powered. Ok, I’m being brief but you seem genuinely curious, so, lemme explain what I mean: In thermo, you would draw a line around a closed system

It’s solar powered. Ok, I’m being brief but you seem genuinely curious, so, lemme explain what I mean: In thermo, you would draw a line around a closed system, and say basically conservation of energy applies in this system. Energy in = work out + losses. In a system where one input is the ocean, you basically just consider that infinite because of the size differences. One dinky little pipe compared to the mass flow into the system from the ocean, that math would be silly to bother with. That said, to swat down the stupid “this is perpetual motion” comments from people with Reddit engineering degrees, you also have to add in the energy input into the system of the sun, which is keeping the water from freezing over the course of 1 million years as it runs someone’s sarcastic water wheel.