I saw a stirling engine on a website in England and had to buy one. It’s sitting on my WD media server which serves as the heat source.
Invented by Robert Stirling in 1816. This cool engine has no exhaust or intake. All the gas stays in the engine and works by the transfer of heat from the bottom of the engine to the top, moving the blue diaphragm with the gas movement and intern moves the wheel.
It works on heat from any source.