Snail Trail Impact on Rooftop Solar PV Plant Energy Generation

The appearance of snail trails discoloration had been visualized through optical images and electroluminescence investigations. The EVA encapsulant also played an important role for discoloration processes which is not only facilitated by its physical but also by its chemical additives. The typical dark traces are discolorations at the position of the grid fingers which are imprinted in the surface of the encapsulation foil. Triggered by moisture, temperature and electrical field a reaction at the silver-polymer interface takes place which leads to the formation of particles containing Ag, P and S migrate within the encapsulation foil. It meant that most of the power losses depended on snail trails appearance. To minimize snail trails, the rigid quality control would be executed and therefore optimize the energy output of the PV module over 25 years lifetime. We interpret our observations with practical analysis based on the results of field measurement. Based on the research we can say that power generation affected between 8 to 32 % due to snail trail compared to ideal Solar PV system. Due to snail trail PV system average 82 kWh/kW Energy generation decrease compare to ideally designed PV system which is 17 %.