PV module degradation mechanisms under different environmental stress factors

Understanding the degradation behaviours of photovoltaic (PV) devices is critical for optimising its financial viability. The degradation of PV modules is dependent on multiple factors such as installation site, mounting conditions, manufacturing process and module types. This means that in order to understand the long term behaviour of PV modules, one needs to assess the stresses acting on the modules (first two factors) and the module’s response to these. In this paper, the possible degradation mechanisms within a PV module according to different stress factors are discussed and linked to typical module constructions. The relationships between degradation mechanisms and electrical performance are analysed as a first step to predict long term power degradation.