Energy and exergy analysis of an integrated photovoltaic module and two-stage thermoelectric generator system

To fully utilize the solar energy captured by the photovoltaic module (PVM) and improve its performance, a coupled system consisting of a PVM, the solar selective absorber (SSA) and the two-stage thermoelectric generator (TTEG) is investigated, where the TTEG considers the Peltier effect, Seebeck effect and Thomson effect. Taking account of the various irreversible losses within the coupled system, the mathematical expressions of energy conversion efficiency, power output, exergy efficiency and exergy destruction rate of the coupled system are established. The numerical results show that the maximum energy efficiency and maximum output power of the coupled system are, respectively, increased by 9.89% and 9.87% compared with a standalone PVM, and the maximum exergy efficiency is 10.4% higher than a standalone PVM. Finally, through sensitivity analysis, it can be seen that the coupled system is affected by several key parameters, including the diode ideality factor, thermoelectric elements, solar irradiance, and PVM operating temperature, so the coupled system can be improved by adjusting these parameters. The results of this paper may provide a new insight into the design and optimization of an actual coupled system.