Performance evaluation of photovoltaic silicon cells under concentrated sunlight

Abstract

The electrical performance of concentrated photovoltaic Si cells has been studied underthe application of real sunlight. The photogenerated current increases linearly with cell temperature at a rate of 5 mA/°C, and it increases with the normal incident solar intensity. The difference between the cell temperature and the lowest cooler temperature increases sharply with incident solar intensity. The module open-circuit voltage decreases with increasing cell temperature. The rate decreases with decreasing normal solar intensity. The module open-circuit voltage increases with normal incident solar intensity. The rate decreases as the incident solarintensity increases. The module efficiency decreases with increasing cell temperature at a ratewhich depends on incident solar intensity and cell temperature. As the incident solar intensity increases, the reduction in efficiency per degree rise in cell temperature decreases. For a given cell temperature, the module efficiency increases with incident power to a maximum and then decreases. A normalised empirical formula relating the incident solar intensity to the cell temperature, for the maximum efficiency condition, is obtained.