Electric energy from thermocouples

AI Thread Summary
Thermoelectric generators can produce useful voltage by creating temperature differences along a wire, but they are generally inefficient heat engines. Practical applications include using them in automotive exhaust systems to power small devices like radios and GPS units. The efficiency of these generators is constrained by the thermal and electrical conductivity of the materials used, as well as the Seebeck coefficient. The choice between connecting thermocouples in series or parallel depends on whether higher voltage or current is needed. Overall, while the concept is interesting, the practical benefits may not justify the cost and effort involved.
Brainiac
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If I were to make millions of contacts or "spots" on a long wire,and connect them in series(or parallel?),then make half of them warmer than the other half,would I get any useful voltage,i.e. electrical energy I could use to power something?
 
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Yes, this is known as a thermoelectric generator. They are rather inefficient heat engines, but they do have some practical applications.
 
I always make allowances for the inclusion of thermionic converters in appropriate circumstances for things that I design. For instance, wrapping the hottest parts of an automotive exhaust system in a blanket of them can provide enough juice to run your radio and GPS at least, and perhaps more. It really wouldn't be cost effective, but it might save a small fraction of a mpg via decreased electromagnetic drag upon your alternator.
It's a fun exercise, but not worth doing in reality.
 
DaleSpam said:
Yes, this is known as a thermoelectric generator. They are rather inefficient heat engines, but they do have some practical applications.

But why is it inefficient? Also one little question: would I need to connect them in series or parallel?
 
Brainiac said:
would I need to connect them in series or parallel?
That depends upon whether you require more voltage or more current.
 
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