Laboratory tests for the evaluation of the degradation of a photovoltaic plant of 2.85 MWp with different classes of PV modules

摘要

This paper studies and analyzes the results of performing several laboratory tests of a sample from a PV plant with 2.85 MW of nominal power that has been in operation for 11 years and whose PV-modules are from different manufacturer and classes. The main purpose is to develop a proper quality inspection that allows knowing the degradation in a PV-plant with these special characteristics. The total sample has been taken in proportion to the size of each class through a proportionate allocation stratified sampling strategy. The tests performed on each sample were detailed visual inspection, power rating, electroluminescence (EL), and electrical insulation. The PV modules tested have been analyzed and evaluated according to an acceptance/rejection criteria established by the laboratory which has been based on International Electrotechnical Commission standards, bibliographic contributions and the warranty conditions of PV-modules. Considering the age of the plant and the criteria established in the power rating, the 80.01% of the sample modules were in good conditions, the 10.27% degraded and the 9.72% rejected. The results also show that the total annual average degradation rate of the PV-plant after 11 years of operation is 0.94%/year.(c) 2021 Elsevier Ltd. All rights reserved.