Non-uniform sizing of PV cells in the dense-array module to match the non-uniform illumination in dish-type CPV systems

To reduce the efficiency reduction caused by non-uniformity of illumination, a dense-array module with non-uniform sizing of photovoltaic (PV) cells is proposed for dish-type concentrating PV systems. The non-uniform-sized dense-array module has been designed and analyzed theoretically at the ideal irradiance of Gaussian distribution, which consists of 48 silicone solar cells. Using the ZEMAX optical simulation software, the realistic distribution of the Gaussian-like facula on the PV module has been modelled in a dish-type concentrator system. The experiments are done under the conditions of different alignments to imitate the different two-axis tracking accuracy with or without a homogenizer. Besides, the performances of dense-array modules with the classical uniform-sized and the proposed non-uniform-sized PV cells are analyzed under various illumination distributions using ZEMAX, respectively. Results show that when the deviation angle of tracking is 0, 0.02, 0.2, the photoelectric conversion efficiency and output power of the proposed non-uniform size dense-array module considerably exceeds the traditional uniform size module. Furthermore, when the tracking deviation angle is no more than 0.02°, it is a very definite possibility that the dish-type concentrator system with non-uniform-sized dense-array module need not a homogenizer as a secondary optical element, which may hence simplify the system structure.