Degradation analysis of PV technologies using NREL and Gantner Instruments outdoor data

Energy yield predictions vs. time depend on both the degradation rates and which parameters are affected e.g. I_SC, FF, V_OC, R_SC, and/or R_OC. These cause site dependent energy yield changes (due to the varying fraction of energy generated vs. irradiance or temperature). This study uses outdoor measurements from the publically available NREL data set and also Gantner Instruments' (GI) in-house data from AZ. Analysis is performed with the normalised matrix method vs. the SRCL/GI Loss Factors Model. The LFM can better identify and quantify degradation including R_SC and R_OC changes. For best understanding these needed the higher quality data from Gantner Instruments measurements rather than NREL which has difficulty finding R_SHUNt.