I get the sense that in the PV market at present, there is a growing appreciation for the quality of components of PV power plants. What is your take on the level of awareness amongst investors, developers and manufacturers about the importance of quality?
The awareness has reached the level of insurance companies and investors, who have a better understanding on that side than in previous years. There was a time when an understanding of what was quality was mainly restricted to those who built components themselves, but now there is a better technical understanding from those who actually buy them. So there are more questions as to what exactly a manufacturer does as well as what is done on project level.
How would you say those questions about quality are best answered then?
Third party certification is important, but as such, is not sufficient anymore. Investors want to know, ‘is a manufacturer able to maintain quality in a day-to-day production process.’ A second question is also, ‘how is it assured that a lifetime assessment has been carried out.’ And this second question doesn’t mean a type approval but what a manufacturer is doing to show that its modules will last long enough in a certain climate.
Does this also apply to the financial standing of a manufacturer, which extends more the bankability area?
Bankability comprises several parts, and one would be the product bankability, where, e.g., extended stress tests and manufacturer audits come to play. The other one would be the company bankability — is the company insured well enough and is there a chance that it can maintain its position in the market?
Our organization doesn’t get involved in these latter questions, but in companies’ abilities to secure quality, while the financial power of a company is better judged by banks who know their business better than we do.
If you say certification alone is not sufficient to ensure quality for investors, do you think that quality of PV park components may in fact be declining?
It is true that certification alone is insufficient, but without it poor quality products would find their way onto the market easily. No I think the misconception has been, for a while now, that certification equals a lifetime testing. Certification is a ‘type approval’ and ‘type approval’ should ensure there are no design flaws so to eliminate the risk of early mortality, the risk that you have a false design. And of course it’s comprised of tests that do simulate some environmental stresses that occur in nature. However, because nobody knows what exact environment the module that is built will end up in, you can’t say IEC Certificate equals 1000 hours damp heat test equals twenty years life in Germany. That’s just not possible because the diversity of technology is huge.
Another factor is that the experience of the industry is just not long enough. Of course there are modules in the market that have lasted 20 years, but they were built very differently than modules are today. So there is this factor of the lifetime correlation and a ‘type approval’ can never give that.
What is the best way of providing lifetime assurances?
I think there is a need to implement a requirement for repetitive testing of modules in the market. That’s something that’s missing at the moment, market surveillance. At the moment manufacturers have their modules tested once and they have their certification via the standard.
Testing organizations have implemented — and we were the first, I think seven or eight years ago — factory inspections, which were not required by the standard. It means that the certification agent comes to the factory and sees if the quality control is good and the materials are actually the same as they were in the test samples. This is voluntary for the test agencies, but it’s required for the test mark from TÜV Rheinland, for example. So the modules need not only to pass the test in the laboratory, but also pass the factory inspection repeatedly.
What I would expect is that there would be an improvement to have such inspections more frequently, maybe unannounced, and also to have some market surveillance testing — where modules are actually bought off the market. This, however, requires quality awareness and differentiation from minimum requirement certification.
Do the factory inspections that you’re talking about also apply to the processes manufacturers employ and also their willingness to remedy certain processes if you find fault with them?
I can currently only speak for TÜV Rheinland, but when we carry out a factory inspection we check mainly three things. One is to look at materials to ensure that the correct ones are in stock and in use and they are not stored over their expiry date. We also look at processes, particularly, what is the lamination profile, for example, and to see whether that is maintained and that there are process records. The third one would be the quality control, to investigate what measures the manufacturer is taking to ensure this quality.
Also when we carry out one of these inspections it is always done by a PV expert who would make a deviation report that also includes recommendations. In follow up inspections, this expert would check whether the deviation as well as the recommendations have been ignored or implemented.