PV Panel and PV Inverter Damages Caused by Combination of Edge Delamination, Water Penetration, and High String Voltage in Moderate Climate

There exist over 2 GW of photovoltaic (PV) systems in the Czech Republic, exposed to moderate continental climate. Although there exist many PV modules defects, thanks to the generally the same production year 2009, only some of them are usual at systems installed in Czech Republic. This work shows delamination failures that are frequent in moderate climate conditions. Special account is taken into edge delamination defect and its possible propagation in modules of standard construction. Combined PV panel and PV inverter failure is caused by edge delamination with water penetration and high string voltage. The electric discharge channel is created between the string of solar panels and the grounded PV panel frames. The result of the discharge channel created because of edge delamination is inverter switch-off and few months later total destruction of the inverter because of protective relay damage. The number of combined PV panel and PV inverter failures is increasing substantially after ninth year of operation of PV panels in moderate climate. Additional sealing of the PV panel frames by transparent polysiloxane gel reduced the number of combined PV panel and PV inverter failures very substantially.

Automated summary

This study investigates delamination failures in photovoltaic systems in the Czech Republic under moderate climate conditions, as well as the resulting combined failures of PV panels and inverters. The findings suggest that the edge delamination defect can lead to significant issues such as water penetration, high voltage, and ultimately the destruction of inverters. Using transparent polysiloxane gel for additional sealing of PV panel frames can effectively reduce the number of combined failures.