In recent years the scientific and public awareness on environmental and energy issues has brought in major interests to the research of advanced technologies particularly in highly efficient internal combustion engines. Substantial thermal energy is available from the exhaust gas in modern automotive engines. The latest developments and technologies on waste heat recovery of exhaust gas from internal combustion engines includes thermoelectric generators, Organic Rankine cycle, six-stroke cycle IC engine and new developments on turbocharger technology. Thermo Electric Power Generator directly converts this Thermal energy into Electrical energy. So number of moving and rotating part has been eliminated. Thermoelectric power generation offer a potential application in the direct exchange of waste-heat energy into electrical power. By this it eliminated emission so we can believe this green technology. In this paper, a background on the basic concepts of thermoelectric power generation and its use in automobile engine is reviewed and discussed.