The Thermoelectric effect can produce electric current from a temperature difference (i.e. potential), but heat by itself can't do any work unless it has someth

The Thermoelectric effect can produce electric current from a temperature difference (i.e. potential), but heat by itself can't do any work unless it has something colder to heat up. Refrigerators just do the inverse, they use an electrical potential to create a difference of temperature between the outside and inside of a box. https://en.m.wikipedia.org/wiki/Thermoelectric_effect https://en.m.wikipedia.org/wiki/Thermoelectric_effect