THERMAL energy may be reversibly converted into electrical energy and vice versa in electrically conducting materials (including semiconductors) by three thermoelectric effects [1]. The Seebeck effect generates an electric potential gradient in a conductor subjected to a temperature gradient under open circuit conditions. The Peltier effect causes heat to be evolved or absorbed when current flows through an interface between two conductors. Moreover, when current flows through a conducting material in the presence of a temperature gradient, heat is also liberated or absorbed due to the Thomson effect. The irreversible effects of Ohmic heating and heat conduction must also be considered in the analysis of thermoelectricity.