– PV module inspection

November was a very rainy month at some Southeast Asian production sites. In some instances (witnessed by STS), the warehouses are not properly managed, and modules may end up stored in rainwater, with risks of degradation of the packaging before shipment, exposing the modules to damage during shipping, and humidity creep through connectors and other interfaces.

We also witnessed, this month, amongst other defects, some projects where the cell characteristics (power and current) were mismatched. Building a module with mismatched cells increases significantly the risk of hotspots, and/or higher long-term degradation rates.

Misplacement of the connectors (ribbons) as well as bad soldering are also a common non-conformity nowadays, and we witnessed these again this month. Any non-homogeneity in soldering may cause hotspots (locally-higher series resistance), and accelerated performance degradation and/or fire hazard.

Depending on the technology (glass-glass versus glass back-sheet) and the encapsulant (EVA vs POE), the placement of the encapsulant may prove critical to avoid bubbles forming inside the laminate. Depending on where these bubbles are found (and this month, we found some at critical locations, for instance, in the area of the junction box), these bubbles may cause delamination and/or water ingress.

We have also seen a relatively high number of scratches on the cells and on the glass this month.

Container loading has not been exempt from improper operations this month. Forklifts are not always well maintained, posing risks of sudden drop of the pallets or even collision. And unsafe operations have been noticed in several occasions, including improper stabilization of forklifts when loading/unloading, and incorrect use of seatbelts. Safety should remain everyone’s number one concern!