Design of a novel concentrating photovoltaic-thermoelectric system incorporated with phase change materials

Since the solar irradiance within a day is varying, the temperature of the photovoltaic-thermoelectric (PV-TE) system becomes fluctuant with the change of the incident solar irradiance, which exerts a significant influence on the efficiency of the total system. In this paper, the phase change material (PCM) is introduced into the PV-TE system to construct a novel PV-PCM-TE hybrid system. The purposes of applying PCM are to mitigate the temperature fluctuations of the PV cell and the TE modules and keep the hybrid PV-TE system operating under a fixed operating condition. A theoretical model of evaluating the efficiency of the concentrating PV-PCM-TE hybrid system is presented. The feasibility of the PV-PCM-TE system with four types of PV cells, c-Si, CIGS, single-junction GaAs, and GaInP/InGaAs/Ge (III-V), are investigated. The optimum operating conditions which indicate that the PV-PCM-TE system has the highest total efficiency are discussed to determine the melting temperatures of PCMs. A series of structure parameters are designed to obtain the optimized parameters for the PV-PCM-TE system, and the influences of these parameters on the PV-PCM-TE system are investigated. The results indicate that the performance of the PV-PCM-TE system is superior to single PV cells and/or PV-TE systems.