l'Actualité du Solaire

The inspector from PI Berlin, who controls the quality of panels made in China, testifies to his experience during the pandemic.

Manufacturers' difficulties

China has imposed a 15-day isolation period for employees who have returned to their families during the New Year's holidays. There were many delays in returning from holidays. Some manufacturers have hired

temporary workers who had no training. The result was an abnormally high rate of defects on the production lines in the following weeks.

Due to travel restrictions and staff shortages, supply problems were immediate. The supply chain was disrupted. Materials stored before the start of the New Year holidays were quickly exhausted. Manufacturers did not return to normal production rates until the end of March.

Panel users were also quick to feel the lack of delivery. This is the case for some developers in Germany in particular, where fixed rates are linked to strict connection dates. The long-term economic viability of some projects has been seriously compromised. Some developers or builders have had to accept older panels. As a result, the contract clauses relating to independent quality assurance have been removed. In addition, some panels did not fit the dimensions of the frames or did not have the appropriate cable lengths for the trackers. Some developers had to accept panels from three different manufacturers and used 12 different parts lists. They had to abandon material traceability and any evaluation of the manufacturing process. The variety of bill of materials could explain why some panels showed a high sensitivity to potential induced degradation (PID) or light and high temperature induced degradation (TID),

To complicate matters further, in a few cases, it has been necessary to deal with the lack of cooperation from manufacturers who have refused to allow PI Berlin engineers access to their plants, despite the absence of Covid-19-related restrictions in the provinces concerned. At the other extreme, however, manufacturers facilitated our transit through checkpoints.

Daily work became an obstacle course. Control measures had to be put in place in record time. These measures consisted of remote monitoring of production by means of video cameras entrusted to factory staff with little knowledge of the production lines.

In cases where panels had already been manufactured and production monitoring was no longer possible, we selected samples to be sent to our Suzhou laboratory. These revealed all kinds of performance (low, medium and high) in the same category, from different batches. Different failures were visible by electroluminescence.

What can we learn from all this? First of all, quality control during the crisis was essential to avoid changes in the selection of components and manufacturing processes not covered by contractual agreements.

SecondlyWe have acquired knowledge of the plants over the past nine years; the flexibility demonstrated by our customers has enabled us to successfully pass our controls in a unique situation. Having said that, a contractual framework between the manufacturer and the buyer that accelerates the implementation of some of our key quality assurance recommendations, could have avoided some of the challenges imposed by some manufacturers.

Last but not leastAs a preventive measure for such future pandemics, panel supply agreements should cover the following points: 1°) recognition of the concept of pandemic as a force majeure; 2°) supervision of production will take place, without prior notice, day and night, to increase control of unapproved components(3) express mention in contracts that manufacturers cannot refuse access to auditors unless a force majeure clause has been invoked.

https://www.pv-magazine.com/2020/05/07/solar-module-quality-control-measures-in-an-age-of-covid-19/

PV Magazine of 7 May