Estimating effects of individual PV panel failures on PV array output

Abstract

Photovoltaic plants are becoming an ever more popular source of energy. While individual photovoltaic panels are quite resilient, failures do happen. As part of decision support it is important to estimate whether it makes economic sense to fix / replace failed panels, or whether they are better left alone. In order to help with such analysis, this work estimates the impact of a single panel short circuit failure on the output of a series-parallel array. Generally, the array power loss is larger than the failed panel's power loss. The dependency of this increase on various factors, such as the number of panels, the shape of panels' current-voltage curve, and the degree of panels' inhomogeneities is investigated. This increase is found to be almost constant for a wide range of parameters, so it is useful in estimating the economic impact of panel's failure without the need to know many details about the system.