Effect of shunt resistance and bypass diodes on the shadow tolerance of solar cell modules

Abstract In the field, solar cell arrays are subjected to shadows from both predictable sources and such unpredictable sources as bird droppings or fallen leaves. The most obvious result of a shadow is a decrease in power output from the solar cell array. However, a more serious problem that can arise is the degradation and eventual failure of the array due to localized overheating. These difficulties can be avoided either by incorporating a relatively small shunt resistance in the solar cell design or by incorporating bypass diodes. In this paper we analyse these techniques and compare their effectiveness.