Initial light-induced degradation study of multicrystalline modules made from silicon material processed through different manufacturing routes

The paper presents results of initial light-induced degradation (LID) of multicrystalline silicon photovoltaic (PV) modules made of crystalline silicon from different manufacturing processes. The modules were installed within the Sunbelt, in Hyderabad, India. Current-voltage (I-V) characteristics are measured and infra-red (IR) images of the modules are taken at regular intervals. A relationship of the IV degradation with the IR images is discussed. Results from laboratory LID tests at room temperature are performed parallel to the outdoor degradation of PV modules. It was found that the total LID, measured on the module level, after the initial 40 hours is similar for both materials resulting in approximately 1.0% degradation of the maximum module power output. This is slightly higher than what was found in laboratory accelerated light induced degradation (ALID) tests at 120°C on the cell level [1].