To follow up on an earlier letter and your reply, Thermoelectric Generators (TEGs) work by generating power from the movement of heat from the hot side to the cold side of a dissimilar metal junction. An important consideration is that TEGs can become heat saturated or worse if you can melt your TEG, so don’t just throw it in the middle of a fire!
I followed a design from “The Boy Electrician” by Alfred P Morgan 1913. It uses German silver wire and copper wire with hammered junctions, there are better combinations but this was easy to get. It would make enough electricity to run a small radio like the kind found on dollar store crank radios or a few LEDs. Modern TEGs are much more efficient and use a solid state Peltier–Seebeck chip. Be sure to buy a high temp solder chip, since the ones used in coolers will melt at much lower temperatures. These solid state devices can also be used with lanterns. In my experiments, I used one attached to a home made brass reflector on a kerosene pressure lantern and produced less than a watt at 3 volts. But several can be ganged [together in series,parallel, or series/parallel arrangements] for higher voltage or amperage. TEG lantern/radios are available.
Shalom, – David in Israel (SurvivalBlog Correspondent in Israel)
Since I have messed with TEGs for some time, I ran across the guys at Hi-Z Technology. Check out the work they and others have done with their product. – Robert, in Nashville, Tennessee