Imagining a giant heat sink makes me think of something pretty dangerous... I picture any part of the heat sink sticking out of the water (I'm guessing it captu

Imagining a giant heat sink makes me think of something pretty dangerous... I picture any part of the heat sink sticking out of the water (I'm guessing it captures heat from the sun?) which becomes hot enough to heat several thousands of gallons of water would produce some really nasty burns for anyone unfortunate enough to touch it. You don't have to explain your idea in detail, of course, but I'd be curious if you had considered a way to safely transfer the energy into the water. Perhaps there is a solar powered way to cheaply heat swimming pools safely... but I'd think the energy might need to be converted to electricity first, since we are already used to controlling and insulating that safely.