Quantitative analysis of crystalline silicon wafer PV modules by electroluminescence imaging

Electroluminescence (EL) images are normally used for qualitative analysis of photovoltaic (PV) modules. In this work, detailed quantitative analysis of crystalline silicon wafer PV modules is achieved using EL imaging. Rather than visually detecting problems, the method presented in this work allows people to construct a series of dark current-voltage (I-V) curves for each individual solar cell in the PV module by calibrating EL signals of the cells. The I-V characteristics of each solar cell can then be extracted, and the problems happened to individual cells can be accurately detected and quantified. This method is proved to be very effective in the degradation analysis of PV modules.