Optimum irradiance distribution of concentrated sunlight for photovoltaic energy conversion

The irradiance distribution on a concentration photovoltaic cell that produ ces maximum conversion efficiency has been found with the tools of Variatio nal Calculus. The analysis is two dimensional and can be applied to a comb- like double busbar solar cell illuminated by a line-focus concentrator. The optimum distribution is, in general, nonuniform, and depends on the intern al parameters of the solar cell: the higher the contribution of the grid to the global cell series resistance, the lower the uniformity of the optimum irradiance distribution. In practical cases, the efficiency for uniform il lumination is close to that of the optimum, but in the latter the irradianc e close to the busbar may be noticeable higher than the average. (C) 1999 A merican Institute of Physics. [S0003-6951(99)02717-5].