Study of a hybrid solar system—solar air heater combined with solar cells

Abstract In a conventional solar thermal system, electrical energy is needed to circulate the fluid. This energy is supplied by an electrical source. A hybrid system, a combination of thermal and photovoltaic systems can generate sufficient electrical energy to turn the pump. The solar cells are pasted directly over the absorber plate. The part of the solar radiation falling on the cell area is converted into electrical energy, and part is collected by the flowing air. A hybrid system is, thus, operated solely by the solar radiation. In this paper, a hybrid system, which is a combination of an air heater and photovoltaic system is analysed. The optimum area of the solar cells necessary to generate sufficient electrical energy for the pump is calculated for different configurations of the air heater. A linear relation has been used to calculate the variation of efficiency of the solar cells with temperature. It is shown that the hybrid system is self sufficient only for certain design parameters and flow rates.