Thermocouples

[Guest pistolpete]

I know that most thermocouples are used to measure temperature using the output voltage, but what about using the output voltage to do work? How much energy (%) can be had from a thermocouple?

[swansont]

It depends on the operating conditions, like temperature differential. This article states "up to 15%" but I think typical values are ~half of that.

[YT2095]

there have been thermopile devices made that will power a small radio when you throw it on a campfire (that was the demonstration), I`ve not heard anything else about this device since the early 80`s though, so maybe it wasn`t commercialy viable?

[DQW]

Research on thermoelectrics is still quite active.

 

To the OP : You want to look up thermoelectricity or thermopower. Here are a few links to get you started :

 

http://www.nanothermel.org/public_main.htm

http://www.rhul.ac.uk/Physics/Nanophysics/thermopower.htm