Design and analysis of dense array CPV receiver for square parabolic dish system with CPC array as secondary concentrator

In this paper, a two-stage square parabolic concentrating photovoltaic (CPV) receiver dish with an overall geometric concentration ratio of 500 suns is designed to provide a uniform intensity distribution on high-efficiency triple-junction solar CPV cell module. The system comprises of a square parabolic dish with an aperture area of 9 m(2) as a primary concentrator and an array of the compound parabolic concentrator integrated optical homogenizer of 0.27 x 0.27 m(2) as a secondary concentrator in tandem with the dish. The CPV module consists of an array of 12 x 12 triple junction CPV cells with each cell connected in parallel or series combination and integrated CPC homogenizer dedicated to each cell. The homogenizer length is selected based on the peak to average ratio of concentrated flux with the aim to maximize the optical and electrical performance of the CPV system. Monte Carlo ray-tracing model is used to predict the flux distribution. The predicted solar flux distribution on individual CPV cells are used as input to determine the electrical performances of the CPV module with three different cell interconnections. For optimized homogenizer length of 0.005 m and receiver height of 3.7 m, the maximum optical and CPV module efficiencies are obtained as 68.30% and 32.03% respectively. A year-round electrical power output of developed CPV system is 2.19 MWh which is up to 33.54% higher as compared to conventional CPV system. The proposed novel geometric design could accommodate the bypass diode for each cell, effectively reducing the current mismatch effects.