Laser Beam Induced Current For Visual Inspection Of Long-Term Exposed PV Crystalline Sulicon Modules

Abstract

Laser Beam Induced Current (LBIC) can be used to generate two dimensional maps of PV modules. Electrical as well as optical defects generate constant in the image and therefore LBIC can be used to complement traditional Visual Inspection of (poly-)crystalline PV modules. Here the method is applied to two modules which had been exposed for nearly 20 years continuously in a natural working environment. The LBIC maps revealed firstly the location of defective cells within the module and secondly the presence of defective areas within a specific cell.