Optical analysis and output evaluation for a two-stage concentration photovoltaic system by using Monte Carlo ray-tracing method

A two-stage reflecting concentration photovoltaic (CPV) system is proposed by this paper. The optical analysis is carried out by using the Monte Carlo ray-tracing (MCRT) method. The relevant probabilistic models required in that method have been established. The effects of the CPV structural parameters on the optical performance are analyzed and a set of the preferred parameter values is obtained. Furthermore, the tracking error and the slope errors of the reflectors are considered in the optical simulation. Their influences on the position and size of the solar image are simulated. Then the scopes those errors should be limited in are proposed through the detailed optical analysis. The complete structural model of the CPV system is finally established. On its basis, the output characteristic of the CPV cell is analyzed in contrast with the flat PV cell. The calculated result shows that the output power of CPV system is higher than that of the flat PV system in some cases. And there is further potential for the CPV system to improve the photoelectric conversion efficiency and reduce the cost.