I'm not an expert but I know of two different technologies to convert heat to power: thermocouples and heat engines. Thermocouples are great because they're sm

I'm not an expert but I know of two different technologies to convert heat to power: thermocouples and heat engines. Thermocouples are great because they're small, can fit in enclosed spaces, have no moving parts and last nearly forever. However, they're not a very efficient way to convert heat to energy. Heat engines + generators can be very efficient, but they're bulky and have many moving parts (you're not going to attach a diesel generator to your cell phone).