The Impact of Haze on Performance Ratio and Short-Circuit Current of PV Systems in Singapore

The spectral content of sunlight directly affects the power output of solar photovoltaic (PV) devices. The extent of the effect of seasonal and weather-related spectral variations on the power output will depend largely on the semiconductor bandgap. In this study, haze, which is a common weather condition in many parts of the world, is found to affect the power output of PV systems. An analysis of a recent haze event in Singapore in mid-June 2013 reveals that haze has an impact on the performance ratios and short-circuit currents of PV systems. The performance ratio of amorphous silicon thin-film PV systems dropped during the haze event, while that of crystalline silicon wafer-based systems exhibited a slight increase. A detailed analysis showed that the main cause of the observed performance ratio variations was changes in the generated short-circuit currents, which were due to a red shift of the solar spectrum arriving in the module plane during the haze period. Therefore, PV systems with different semiconductor bandgaps were affected differently.