Thermoelectric generators are devices that convert temperature differences into electrical energy, using a phenomenon called the "Seebeck effect" . Their typical efficiencies are around 5–8%. These are solid-state devices, and have no moving parts.
A great misconception of how Thermoelectric Generators work is that they simply convert heat sources to electricity. Thermoelectric Generators work on temperature differences; they just need a high potetial temperature on the hot side and a lower potential on the cold side. For example, power can be generated if the hot side is 0 C and the cold side is -100 C. As long as the temperature difference is great enough for the level of power you are looking to generate. Some thermoelectric generators, like systems developed by Tegpro, can generate power when the potential temperature differential reverse polarity.
A Thermoelectric Generato Module or TEG Module is the core of a Thermoelectric Generator. The module itself converts the potential temperature differences to electricity while passing a portion of the power the the cold side. Some Thermoelectric Generator Modules have a mx temperature rating of 100 C while some can goes as high as 350 C such as the Thermoelectric Generator Modules that Tegpro manufactures. These high temperature Bismuth Teluride modules use a high temperature solder with reflow at temperatures in excess of 400 C.
Tegpro Thermoelectric Generator Modules available at Tegmart
The Seebeck effect involves a temperature differential across the module by heating one side of the module and cooling the opposite. A Seebeck Module is a thermoelectric generator TEG and a Peltier Module is a thermoelectric cooling module TEC. You can use a TEC as a generator but will not be able to produce much power because of materials used to bond the device together are low temperature under 220°F. To produce meaningful power you will need to expose the hot side to temperatures well above 350°F range. Also have the cold side remove heat and maintain temperatures of 100°F or lower if possible.
Thermoelectric Generators work on temperature differentials. The greater the temperature delta of the hot side compared to the cold side, the greater the amount of power will be produced.
Two critical factors control Thermoelectric TEG power output:
1. Temperature Delta: the temperature of the hot side less temperature of the cold side.
2. The quantity of heat that can be moved through the module.
Great effort must be placed on both the heat input design and especially the heat removal design. The better the TEG Generator construction is at moving heat from the hot side to the cold side and dissipating that heat once it arrives to the cold side, the more power will be generated. Thermoelectric Seebeck Effect modules are designed for very high power densities, up to 50 times greater than Solar PV. Thermoelectric Generators using cooling liquid perform better than any other method of cooling and typically produce more net additional power than a pump consumes.
More information about Thermoelectric Generators (Wikipedia)
Videos of Thermoelectric Generators (YouTube)
Thermoelectric Generator Forums (TEGPower.com)
More information Web Sites about Thermoelectric Generators below:
Basics of Thermoelectric Generators
Thermoelectric Generator Definitions
Basic information on the Thermoelectric Generator
More information on the Thermoelectric Generator
Electricity from Heat Educational Page
Stove Lite (World's First Wood Stove Powered Thermoelectric Lantern)
Devil Watt (Wood Burning Stove Thermoelectric Generators)
TEGPRO (Experts of TEG systems)
Tegulator (Complete line TEG power regulators Made in the USA)
Tegmart (Online Store: Wood Burning Stove Thermoelectric Generators, Energy Harverting Regualtors (Tegulator), and other Accessories)