Thermoelectric conversion is a general term of the phenomena in which heat is generated from electricity, or vice versa, due to the characteristics of certain substances. The substances (conductors or semiconductors) that cause such phenomena are called thermoelectric conversion materials.
The major phenomena of thermoelectric conversion include the "Seebeck effect," in which electricity is generated by applying a temperature difference to thermoelectric conversion materials, and the "Peltier effect," in which heat is radiated (heated) or removed (cooled) at an electrified junction surface when an electric current is made to flow through thermoelectric conversion materials with electrodes attached at both ends. The Seebeck effect has been applied to power generation modules of artificial satellites, and the Peltier effect has been used for temperature control systems of wine cellars, among other applications.
More recently, attention has been paid to technologies utilizing the Seebeck effect, from the perspective of more efficient energy use and reduction of CO2 emissions. However, power generation utilizing the Seebeck effect still has issues to address, such as the fact that "the materials are expensive" and "power generation efficiency is too low to justify general use." Accordingly, endeavors are being made for developing new materials that can raise the power generation efficiency and reduce costs through mass-production.
