Can Bad Solar Cells Make a PV Module More Efficient?

Abstract

In this paper, we propose an analytical theory of the "knee" voltage (Vknee) in a partially shaded module with bypass diodes. We find that knee voltage depends on the module configuration and it is independent of the number of shaded cells protected by each bypass diode. In addition, we propose two independent solutions to increase the knee voltage, which will significantly reduce the disproportionate power loss under partial shading conditions. The first solution involves using solar cells with low reverse breakdown voltage and the second solution is based on placing low shunt resistance cells in shading prone areas of the module.