You can power any thermal pump using thermal energy. There is refrigerators that you have to light up the burner to make them run. They use that heat to drive a reverse cycle which then pushes the heat out of the box. Pretty much passive, you just add heat, and the pump uses it to move the heat out of the box. It could be a geothermal spring or a mining farm.

bugger me amazon puts a lot of tags on their links. Always use "get clean link".