Performance analysis of a novel CPV/T system with curved CIGS modules: Comparison with traditional flat modules

Abstract

Concentrating photovoltaic/thermal technology is a high-efficiency but low-cost approach for power generation and high-temperature heat extraction by utilizing solar energy. However, the high temperature, uneven light spot and temperature distribution are the core issues causing electrical efficiency degradation and cell damage, seriously affecting the reliability of the concentrating photovoltaic/thermal system. Although efforts have been made to address the problems by efficient cooling or concentrator improvement, the receivers are always crystalline silicon modules with flat surface. This is the first time to propose the novel concentrating photovoltaic/thermal system employing curved CIGS (CuIn_xGa_1−xSe₂) receiver. After particle swarm optimization, the standard deviation of local concentration ratio drops from 4.75 to 3.00. On the selected day, the illumination uniformity is optimized by 58.22 %, the maximum temperature difference drops from 24.9 °C to 14.79 °C, and the standard deviation of surface temperature is reduced from 5.61 °C to 2.71 °C, meaning the temperature uniformity is optimized by 51.69 %. With a smaller shading area, the curved receiver also saved 0.3 MJ solar energy, resulting in higher final water temperature at 87 °C. Although the reference efficiencies of CIGS at 16 % is lower than that of c-Si at 17.8 %, the proposed system still produces 4.3 % more electricity than traditional system and generates 6.8 % more electricity than the system with flat CIGS receiver. Over the whole day, the overall efficiency is 68.92 %.