Traces

Traces under the photovoltaic panel

These marks are the result of chemical reactions happening inside the solar panel. Key panel components like the silver paste used for the conductive lines of the cells and the Ethylene Vinyl Acetate (EVA) sheet encasing the cells generate snail trails mostly via a chemical process. The Potential Induced Degradation or PID effect in solar PV panels affects your system by consistently reducing the power of the modules. In 2012 it was reported that about 50% of all newly installed modules were more or less affected from “snail. . Instead, it's a visual sign of chemical and physical changes inside the panel that may affect performance, longevity, and reliability. [PDF Version]