Overview on Themoelectrics

Thermoelectrics have two different modes of operation: power generation and temperature control.

Nearly two-thirds of the energy produced in the US is released into the atmosphere as waste heat and is not actually utilized for processes that require energy. It is possible to regain some of this waste heat and convert it back into useable energy by using thermoelectric power generators which create electricity using a temperature gradient as the fuel.

U.S. Energy Using in 2013
While the overall percent of energy rejected as waste heat is approximately 60%, the percentage of waste heat in transportation is even larger at nearly 80% (data collected and analyzed by Lawrence Livermore National Laboratory and the Department of Energy)

There are many applications for both power generation and temperature control, only a few of which are listed below:

Power Generation Cooling/Heating

Existing Power Plants

Cooling Infrared Sensors on Satellites

Vehicle Exhaust Systems

Temperature Control of Lab Equipment

Space Vehicles (Mars Rover/Voyager)

Heated/Cooled Vehicle Seats

These two different modes can be achieved by either placing the device in an existing temperature gradient or applying an electrical current. When the device is placed under a temperature gradient, charge carriers flow away from the hot side of the device and create an electrical current which can be used as electricity. When an electrical current is applied the charge carriers flow from one side of the device to the other results in the cooling/heating of opposite sides.

Thermoelectric Unicouple

This is a solid state process meaning that there are no moving parts. To achieve the thermoelectric effect, two different materials are arranged in a unicouple which can then be placed electrially in series and thermally in parallel to develop a device of the desired shape and size.

Thermoelectric device in power generation mode

Research in this field is necessary to improve the materials properties and themoelectric efficiencies of the resulting devices.