im thinking something small.

there are some 12v output units on AliBaba. Though a 5v 3amp unit would be cool.

i use a woodstove fan every day that works on the same principle.

a base to transfer heat to one side of the plate, and a heat sink on the other to create the temperature difference needed to create current.

its not going to charge a battery bank, but capturing heat as charging electricity for devices sounds cool to me. especially since im burning a fire every day in the winter…

interesting winter tinkering project…