Optical efficiency study of PV Crossed Compound Parabolic Concentrator

Static solar concentrators present a solution to the challenge of reducing the cost of Building Integrated Photovoltaic (BIPV) by reducing the area of solar cells. In this study a 3-D ray trace code has been developed using MATLAB in order to determine the theoretical optical efficiency and the optical flux distribution at the photovoltaic cell of a 3-D Crossed Compound Parabolic Concentrator (CCPC) for different incidence angles of light rays. It was found that the CCPC with a concentration ratio of 3.6× represents an improved geometry compared to a 3-D Compound Parabolic Concentrator (CPC) for the use as a static solar concentrator. The CCPC has a maximum optical efficiency of 95%, in line with the optical efficiency of the 3-D CPC, with the added advantage of having a square entry and exit aperture. A series of preliminary experimental measurements were taken on a setup of nine solar cells. The experimental results provide validation of the MATLAB code developed, showing a deviation of 12 ± 2% from the simulation results, thus confirming that the code can be used to investigate different concentration ratios of the CCPC.