Nothing fancy here just had some ¼ inch copper and steel tubing laying around. I decided to make a thermogenerator and did so by cleaning the ends with sand paper. Then I smashed the ends with vice grips so that they were flat (I figured more surface area the better). Next I began soldering the two ends together mostly making a mess because I had no flux. It holds!
Once it was finished it worked great. I produced about 10mv with ~ 100°C temperature difference. I predict that in an array I could easily produce ~5Volts, enough to do some work. I imagine that a car muffler / engine, camp fire or even the sun on a cold day would make a fair amount of voltage. Free energy sure, but at less than 10 percent efficient it’s not a show stopper.
One other Item you may be interested in. I can use this reversely and it would make a great temperature sensor. Just apply some voltage through a pull up resistor and read the voltage drop it produces with respect to temperature.
