A method for accurately assessing field performance degradation of PV modules in different geographical regions

Abstract

Solar photovoltaic (PV) technologies have developed rapidly in recent years. As the core part of PV system, performance of PV modules largely determines the output of PV system. Module performance gradually degrades during operation, and the degradation is generally variant at different sites due to the differences in climatic stresses. Thus, it is necessary for sites selection of PV power stations and investment decisions to accurately assess field degradation of modules in different locations. In this work, an approach to assess and predict module field degradation in different regions through mathematical modeling and regional clustering was introduced. First, a mathematical model describing the relationship between climatic stresses and module performance degradation was established using cumulative damage model. Moreover, considering geographical region attribute of model parameters, a scientific method, namely regional clustering based on climatic stressors, was further developed to predict the module degradation at different locations, which guarantees its prediction accuracy. Compared to existing approach, cumulative fitting deviation of estimated degradation rates obtained by this model was reduced by 23.46%. Meanwhile, relative deviation of estimated degradation rates in different places was reduced to 1.61% and 0.4% with instruction of regional clustering result, which validated the effectiveness of the overall method.