Interview: Cheap PV and quality can go hand in hand

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Quality’ is a term that has become rather abused over time. Are there really as many problems in this area as assessors might like us to believe?

Firstly, there are undoubtedly many quality problems that haven’t become apparent yet in lots of systems. You don’t recognize defects in modules at first glance: they only come to light in the field – after perhaps 7 or 8 years. But then there are also those installation problems, which you see straight away, and which have an immediate impact.

Such as?

You see a really mixed bag of defects. For example, poles wired wrongly, cables that are too small, or which aren’t suitable for outside use. Then there are the usual kinds of assembly problems that can, for example, lead to a combiner box going up in flames. Or problems with the mounting frame. Just last week, I was at a site and had a look at the substructure. Even though the site manager was certain it had plenty of strength, you could see just by looking at the thickness of the materials used, that the project had been thrown together in a quick and dirty way. What load it will actually take is open to question. In the job you really see lots of very different problems. I’d need a couple of days to tell you about all of them!

How often do modules have to be returned?

That an entire module has to be returned only applies to a small percentage of them. It only happens with modules that are badly damaged – where the glass panes have shattered, the terminal boxes fall off as soon as you unpack them, or where the frames are totally broken. It’s difficult to quantify exactly how many modules are affected, since it’s an issue no one is very willing to talk about. However, in the main modules aren’t damaged beyond repair, so you find a solution of some sort. That might involve the sending off for a replacement part or a rebate against the price.

Where is there room for improvement in the photovoltaics industry?

It’s important, for example, that installers and companies in general buy goods against clearly defined contracts. These must include quality control clauses, which go beyond producing a certificate and then hoping everything will be fine. You have to check that the goods produced in the factory really match those which have been promised. To know that, you have to define very precisely what you will get. This goes well beyond the module’s data sheet, and the terms and conditions of the certificate. This will be a topic at the Quality for Photovoltaics workshop.

What’s the view of the banks?

To date, they’ve had to put up with quality assurance that’s been far too lax. A calculation of the size of the loan is made in advance on the basis of a yield assessment. But that’s not actually the right basis. If the system is built so differently or so poorly that it can never produce the calculated yield, then the assessment doesn’t help. So we’re seeing a definite trend – that we’re pushing for – that you make a detailed inspection of the system after completion, and then fine tune the amount of the loan on this basis. For example, by checking the modules are ok and how well they pass a sample test. Only then do you know that the system has been built well and that it will produce the forecast yield. That of course implies that there must be a good manager for the system’s operation and not a fly-by-night company, which perhaps visits the site every 5 days and only then notices that it might not be operating properly. I must also say though, that I get annoyed by the attitude of many investors, who just want to please the bank and use the bank as an excuse during negotiations. You hear all too often that the bank has instructed us to do something. But it’s actually the investor’s money that’s in the project. When it comes down to it, the investor and the bank are sitting in the same boat.

How can quality improve, when currently the overriding concern is to become cheaper? Cheaper and better at the same time – can they go together?

Sure, of course they can go together. It’s just a matter of degree. Currently, all manufacturers are losing money on production. So it’s obvious many will skimp on the quality of the raw materials, out of sheer necessity. That’s why it’s so important that, during further funding cuts and when planning systems, you allow for the fact that it will take 1 or 2 years before the financial return will recover. An example of lowering costs without affecting quality can be shown with the substructures. They often look very good. But often it would be adequate to use non-galvanized steel. That wouldn’t involve any loss of quality.

What’s the aim of the quality workshop?

We have to continue to raise awareness of the fact that we are a long way from a set of clearly defined standards that cover quality assurance from the manufacture of the silicon right through to the 25th year of operation. We have to work around that. We often get the situation that customers hear from the manufacturers that their quality assurance wishes are something extraordinary. In a workshop like this, you will see there are a multitude of other customers who also want the same – and are able to get it. That allows you to be more assertive in negotiations. And manufacturers too can see just what customers sometimes think up so that they can get a lower price, and so can react accordingly.

Quality for Photovoltaics

Solarpraxis, which also publishes pv magazine, is organizing a workshop on Quality in Berlin on September 6. The goal is to create an opportunity for discussion between bankers, investors, manufacturers, distributors, designers, certification bodies and test laboratories. The speakers will address the main problems in building systems and about guarantee models, using examples from practice.

Edited by Becky Beetz.