Defect Rate In Solar Modules Going Up Post 2022, Says Engineering Services Firm

Clean Energy Associates, a solar engineering services firm with offices in the US and China, has flagged a serious emerging risk from module quality that can put projects at risk. The firm claims to have performed EL inspections on over 300,000 modules in the field to arrive at its conclusions. The evaluation of solar risks is in line with the mandate of Clean Energy Associates to provide services to mitigate such risks.

What is EL testing?
Electroluminescence (EL) testing is a diagnostic technique used in the solar industry to detect defects in solar cells and modules that cannot be seeing with the naked eye. By passing a current through a solar module in a dark environment and capturing the emitted infrared light with specialized cameras, EL testing identifies issues such as microcracks, broken cells, soldering defects, and inactive areas.

Post its checks and analysis, the firm declares that microcracks have gone up by a massive 47% since 2022, after being on a downward curve since 2020. Thus, while Line Cracks, which was exhibited by 83% of sites it checked can lead to minor power loss, soldering anomalies, which it spotted in 73% of the modules, can impact cell efficiency as well as create hotspots that damage the modules.

Edge ribbon cracks was another deficiency it found in primarily half cut modules, making them a serious long-term risk as these are more likely to grow.

While other issues it discovered like presence of foreign materials, glass stains, laminate bubbles or even cell to cell defects can all lead to lower efficiency than promised, something like cell to edge of glass defects which it discovered in 52% of the sites can lead to more serious issues like internal arcing or fire.

The firm blamed most of the defects to the manufacturing stage, making the case for a more robust quality check process at manufacturers. Readers need to be aware that these are the services the firm itself offers, so it is in its interest to highlight such issues.