EnGen Roadshow Demo: Thermoelectrics

How It Works

Source: RTI International

A Thermoelectric module (TEM) is a solid state heat pump consisting of 2 semiconductor elements sandwiched between two ceramic plates. Applying a dc voltage will cause the flow of electrons from the p to the n-type element, carrying heat from the "cold side" to the "hot side" of the module. Reversing the voltage will result in heating of the "cold side". If a temperature gradient is created between the "cold" and "hot" sides then a voltage will be created which can be utilized to power an external load.


How It Is Used Today

TEMs are used today for both power generation and refrigeration. They are used for power generation in deep space currently. They will be used for power generation in BMW cars starting in 2013. They are currently used in cars to heat or cool seats. Many other portable cooling products exist that make use of TEMs.


In the early 1800s Jean Peltier discovered that passing electric current through two conductors creates a heating or cooling effect. Thomas Seebeck found that two dissimilar conductors at a temperature difference creates a voltage. William Thomson (Lord Kelvin) demonstrated that a single conductor placed over a temperature gradient with current flow will exhibit reversible heating and cooling. Since the 1950s, TEMs have become a commercially viable technology for small cooling applications. TEMs find modern day usage in NASA deep space exploration as the power source of satellites and rovers who are too far from the sun to use photovoltaics. Additionally, TEMs are used for waste heat recovery in smelting plants where a temperature gradient exists that allows them to utilize the heat for power production.

Projects You Can Do At Home

$10 TEM

Additional Information