4.6 - Thermoelectric generation using solar energy

Abstract

Sun is an infinite source of energy and solar energy is inexhaustible. Photovoltaic (PV) cells are one of the best-known devices with a high conversion efficiency of the solar energy into useful electric power. It is well recognized that the main restriction of the PV cells is the temperature that affects the conversion efficiency significantly. Thermoelectric generator (TEG) is able to address this challenge by converting the waste long-wavelength thermal energy into useful electricity. Special features of the TEGs such as having no mechanical moving parts, a long lifetime, and high reliability make this technology a viable and promising alternative to integrate with PV cells especially in the high-temperature applications. Although TEGs can be used alone as solar thermoelectric generators (STEGs) devices in order to directly use solar energy as a heat source, these devices can be used in hybrid PV-TEG systems to harvest the heat produced by the PV cells. In order to take advantage of this hybridization and to provide an efficient and high-performance STEGs, it is necessary to tackle structural, electrical, and thermal challenges in designing the system in relation to various and variable solar irradiations. This chapter studies the effect of the solar irradiation variation and structural design of the STEG on the system performance. Moreover, the challenges are discussed through accurate analysis techniques with a focus on the thermal coupling effect between the layers of the modules.