Thermoelectric generator

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Thermoelectric generators (also called Seebeck generators) are devices that convert heat (temperature differences) directly into electrical energy, using a phenomenon called the "Seebeck effect" (or "thermoelectric effect"). Their typical efficiencies are around 5–8%. Older Seebeck-based devices used bimetallic junctions and were bulky. More recent devices use semiconductor p–n junctions made from bismuth telluride (Bi2Te3), lead telluride (PbTe),[1] calcium manganese oxide, or combinations thereof,[2] depending on temperature. These are solid-state devices and unlike dynamos have no moving parts, with the occasional exception of a fan or pump.

Radioisotope thermoelectric generators can provide electric power for spacecraft. Automotive thermoelectric generators are proposed to recover usable energy from automobile waste heat.

Uses[edit]

Thermoelectric generators can be applied in a variety of applications. Usually, thermoelectric generators are used for small applications where heat engines (which are bulkier but more efficient) such as Stirling engines would not be possible. Another deciding factor is that while inefficient, thermoelectric generators are more reliable and have a smaller chance of breaking over time and use. Spacecraft are a typical example of an application where maintenance is next to impossible after launch.

Efficiency[edit]

Thermoelectric generators typically have lower efficiency than mechanical generators such as Stirling engines, i.e. they generate less electric power for the same heat flow. For a discussion of the factors determining and limiting efficiency, and ongoing efforts to improve the efficiency, see the article Thermoelectric materials - Device efficiency.

Limitations[edit]

Besides low efficiency and high cost, two general problems exist in such devices: high output resistance and adverse thermal characteristics.

See also[edit]

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