Effects of leg geometry and multistaging of thermoelectric modules on the performance of a photovoltaic‐thermoelectric system using different photovoltaic cells

Abstract

Research into improving the performance of photovoltaic (PV) systems using thermoelectric generators (TEGs) has gained increased interest in recent times. Few studies have separately investigated the effects of multistaging, thermoelectric geometry, and type of PV cell on overall performance of PV-thermoelectric (PV-TE) systems. Thermoelectric leg geometries considered in these studies were either rectangular or trapezoidal legs. The research work related to examine the combined consequences of PV cell type, TEG leg geometry and multistaging on the overall performance of PV-TEs has not been carried out till date. Therefore, a three-dimensional model of this hybrid system considering two different types of PV cells and the rectangular and circular TEG leg geometries in single and multistage arrangements has been investigated using ANSYS 2020 R2 software. A parametric study considering the effects of concentrated solar irradiation, TEG cold junction convective film coefficient and load resistance on the overall performance of the hybrid system has been carried out. Results show that, for both types of PV cell, the circular leg geometry of TEG provides the highest PV-TE performance. Also, the PV cell type significantly affects the optimum number of TEG stages in the PV-TE system. Finally, multistaging increases the thermal stresses developed in the PV-TE system, although the circular leg TEG provides the least thermal stresses as compared with the traditional rectangular leg TEG. Quantitatively, the PV-TE system with single and two-stage circular leg TEGs reduced the thermal stress levels of their rectangular leg counterparts by 3.31% and 0.78%, respectively. The findings of this study can be used as a reference for all types of PV cell in the PV-TE systems.