Snail Trails and Cell Microcrack Impact on PV Module Maximum Power and Energy Production

Abstract

This paper analyzes the impact of the snail trail phenomena on photovoltaic (PV) module performances and energy production. Several tests (visual inspection, maximum power determination, dielectric withstand, wet leakage current, and electroluminescence test) were carried out on 31 PV modules located in a PV plant in Italy. The electroluminescence test highlighted the strong correlation between the appearance of snail trails and presence of damaged cells in PV modules. The daily energy produced by four PV modules affected by snail trails ranged between 68% and 88% of the energy produced by a damage free commercial PV module over the same period.