Estimation of operating temperature and energy output of concentrator photovoltaic module under concentration conditions

Abstract

The operating temperature of a concentrator photovoltaic (CPV) module is a dominant factor in its conversion efficiency. It is necessary to reduce the operating temperature to generate a high output of a CPV module under field operation. Therefore, we estimated the operating temperature and conversion efficiency of a cell or module under real concentrating operations. First, we developed a heat transfer model for the CPV module. The operating temperature in the CPV module was calculated as functions of the thermal resistance and the heat transfer coefficient. A low thermal resistance between the solar cell and the back-surface and a high heat transfer coefficient of the back-surface were effective for reducing operating temperature. Next, the conversion efficiency of a triple-junction solar cell was calculated using an equivalent circuit simulation. We can evaluate the cell performance under actual operating conditions using the calculated operating temperatures of the cell.