What causes small leakage currents in photovoltaic (PV) modules?

ABSTRACT: Small leakage currents flow between the frame and the active cell matrix in photovoltaic (PV) modules under normal operation conditions due to the not negligible electric conductivity of the module build-ing materials.

What is the difference between PA-like and FC-like PV modules?

“PA-like” is characterized by moderate leakage resistance loss and slower performance reduction with regard to insulation in the field. “FC-like” is characterized by high susceptibility to water and a high leakage resistance loss rate for PV modules after 6–8 years of operation.

What is a PV module investigation?

PV module investigation included infrared spectroscopic (Raman and NIRA) identification of the BS material and layout as well as water ingress, 25 module IV-measurements to determine the electrical performance, and leakage resistance/leakage current (LR/LC) measurements to ensure proper operational readiness.

Does soaking a PV module reduce LR?

From the leakage test for functional PV module ( LR > 15 MΩ), we observed that soaking a PV module for 1 h, LR will be reduced by 20%–30% of LR0 for FC-based SF-BSs, 5%–10% of LR 0 for PA-based NF-BSs, and 1%–5% of LR 0 for DF-BSs.

Which path is most important for leakage current along a glass/Eva?

The leakage current along the glass/EVA is dominat-ing for all temperatures and relative humidities. The second most important path is the lateral conduc-tion through the glass except for 85 °C and 85 % RH. At a high RH of 85 % the conduction along the glass surface becomes important and accounts for up to 38 of the total leakage current at 85 °C.

How does weather affect water leakage resistance?

Water is easily and rapidly absorbed and released by the FC-based BS, which happens when ambient conditions change. As a result, weather-dependent performance variations are expected. With increasing water ingress, the leakage resistance drops strongly.