Numerical simulation and experimental validation of a high concentration photovoltaic/thermal module based on point-focus Fresnel lens

Abstract

Characteristics of a high concentration photovoltaic/thermal (HCPV/T) module equipped with point-focus Fresnel lens have been investigated in this paper. Both electrical and thermal models of the module are developed by numerical methods. The electrical model is based on the Shockley diode equation, and the thermal model is grounded on a two-dimensional steady-state heat transfer model. Influences of environmental parameters and coolant water are considered in the models. The inputs of the models consist of irradiance, ambient temperature, wind speed, water temperature and mass flow rate. The outputs mainly include electrical efficiency and thermal efficiency. The simulated results are compared with experimental results and a great agreement is obtained. By the virtue of the validated models, influences of different parameters on module performance are analyzed in detail. The results show that an electrical efficiency of 28% and a thermal efficiency of 60% can be obtained by the HCPV/T module. The electrical efficiency is mainly influenced by solar irradiation rather than cell temperature. The thermal efficiency increases with the increment of irradiance, ambient temperature and water mass flow rate. On the contrary, increasing water temperature and wind speed will lower the thermal efficiency. Also, the HCPV/T module can produce hot water as high as 70°C without decreasing the electrical efficiency seriously.