Power Degradation Caused by Snail Trails in Urban Photovoltaic Energy Systems

In recent years, a discoloration defect called as the snail trials emerged on crystalline silicon solar module in urban photovoltaic energy systems. It resulted in power degradation, and caused a serious concern about effects of this phenomenon on crystalline silicon solar modules, but very few publications have dealt with this phenomenon. In this paper, the crystalline silicon solar modules with snail trials are investigated by I-V and P-V characteristics, electroluminescence (EL) technique, thermography analysis, and energy production in photovoltaic power plant. The obtained results show that the snail trails may affect output of power for crystalline silicon solar modules compared with reference module, the energy production measured was about 9.1% lower than the normal array.