Winaico on large PV module formats and n-type products

When it comes to PV module technology, the past year has been all about the introduction of new wafer/cell size formats. Where does Winaico stand on this issue?

Sascha Rossmann: Currently we are focusing on the M6 (166 mm) wafer. Going into next year, we will be migrating to the M10 (182 mm). In terms of power that will mean roughly 400-410 watts on the 60 cell format and 500-550 on the 72 cell format. We don’t see as much innovation in cell technology these days, it’s all about wafer size and cost reduction. If you really want to increase efficiency, you have to go to double or even triple-junction cells, and this is still a long way off.

What are the challenges to switching to the M10 format? Does it require a lot of new production equipment?

Absolutely, you need to change the whole production line. The stringers and all the layup for the solar cells need to be upgraded. And you also need higher levels of automation because the alignment of the cells needs to be even more precise with much narrower gaps. This is a challenge for a lot of smaller manufacturers.

Marc Ortmanns: On the market side, when we look at the rooftop segment in particular there is a bit of a conflict of interest. On the one hand, there are manufacturers who want to bring costs down and see larger formats as an effective way to do this. On the other, you have the rooftop PV installers, all of whom prefer smaller dimensions. I think the 400-410 W panels with dimensions of 1.709 x 1.135 mm are a good fit, anything larger simply isn’t practical to install on a rooftop.

Our customers focus very much on private and small commercial PV installations – the average system size that we ship is around 15-20 kW. So size is a key criterion, that is in contrast with many of the larger Asian manufacturers and OEM suppliers that focus on PV modules for large-scale projects. While shifting to the M10 we are still trying to keep the panel as small as possible to be the best fit for European rooftops.

In recent months we’ve seen a few more PV module makers take their first steps into n-type technology. Is this also on Winaico’s roadmap?

SR: We are working on that, but we don’t have a concrete product yet. Two or three years down the line we expect to see a major migration to n-type, once this current move to larger wafer sizes has run its course. And within n-type, we see that TOPCon is the lowest cost option, but we have found that if you really want to see a significant efficiency increase you have to look at heterojunction. In combination with back contact this will bring module efficiencies up to the 23% mark.

What else is coming up on the company’s technology roadmap?

SR: We are working on rapid shutdown (RSD) technology, with some demonstration systems already set up in Taiwan. We have developed our own microchip to control the junction box, leveraging our production base in Taiwan and the island’s leading position in the semiconductor industry. We are testing it in Taiwan as well, because we expect to see a tightening of RSD regulations here, given the high ambient temperatures and the very expensive buildings where solar is being installed: If you install a PV system on a US$10 billion factory, you don’t want that system to cause a fire. And with so many high-tech, expensive factories in Taiwan the government is considering stipulations for RSD.

Currently, RSD is usually managed by the inverter, but by integrating it at the module level we offer customers more flexibility. It’s a valuable additional function for the rooftop market, and you have to develop a whole printed circuit board with all the technical signaling and so on, which is not easy to do.

Aside from Taiwan, where are the key markets for Winaico’s products?

MO: For us, it’s still Europe. That’s where we started back in 2008, and it’s still our major market, with 50-60% of our capacity being sold in Europe. We have a strong, loyal customer base here, and they appreciate that we have maintained a stable presence in the market for years, with a continuous team, never changing our approach. We have our strongest base in Germany, and we have been expanding into other European regions, for example, BeNeLux, Scandinavia, Poland, and Italy. Outside of Europe, we are strong in Australia, Japan, the United States, and of course Taiwan as well.

How do you see these markets at the moment?

SR: In all of these regions we are focused on residential and commercial markets. We have a few megawatt-sized systems but that is quite rare. As a manufacturer, we are very much a niche player, not just from a capacity standpoint but also from our portfolio. We target a narrow group of installers that focus on this private sector. In this segment, we see that the growing ‘green wave’ toward storage and electric vehicles has created a lot of new demand and also a whole new way of selling.

MO: In the past, the panel was the main topic that the end-user was interested in. Now the storage solution is key, and the panel has become just a part of the whole system that is driven, marketing and sales-wise, by the storage solutions. To promote yourself as a PV panel manufacturer in this space, the softer skills of forming long-term customer bonds and being reliable in terms of quality, service, warranty handling, and these other relationship aspects become more important.  This is a strategy that we first started with more than 12 years ago, and the way we take care of the relationships on the installer side today.