In-situ inspection and measurement of degradation mechanisms for crystalline and thin film PV systems under harsh climatic conditions

The assessment of photovoltaic (PV) modules performance and reliability at operating conditions is very important considering the large investment in PV power plans. One of the important parameters on PV modules reliability is the degradation rate (Rd). This parameter has an important implication on the return-on-investment calculations. The aim of this study is to investigate the degradation rates of two PV technologies (monocrystalline (m-Si) and thin film (TF) based) after more than two years of outdoor exposure in semi-arid conditions. In the first step, the performance drop of the electrical parameters will be analysed for each technology. After that, comparison of the technologies durability in harsh atmosphere will be presented. Moreover, modules with the highest degradation rate values were selected for electroluminescence (EL) measurements to deeply investigate the degradation. The results show that the average powers Rd are 1.5 %/year and 1.73 %/year for the m-Si and TF modules respectively. Those values are significantly higher than those reported either in the literature or those employed in financial calculations. (C) 2019 The Authors. Published by Elsevier Ltd.