On-Site Electroluminescence Study of Field-Aged PV Modules

This paper presents the analysis of the electroluminescence (EL) images taken on site during the All India Survey of Photovoltaic Module Reliability 2016. Cracks have been detected in most of the PV modules which show poor performance. The percentage of cracked cells is higher in young (age<; =5 years) modules as compared to the old (age > 5 years) modules, and also in modules rack-mounted on the roof compared to those mounted on the ground. The power degradation rate was found to increase with increase in the number of cracks in the PV module. Cracks were found to cause fill factor degradation in the modules which is responsible for the power degradation.