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Raising the bar for thin-films: an interview with Solibro Managing Director Dr. Karl-Peter Merz on developing record-breaking CIGS technology

Dr. Karl-Peter Merz
Dr. Karl-Peter Merz

Dr. Karl-Peter Merz serves as Managing Director for Solibro, a subsidiary of Q-Cells SE. On March 29th, 2011, Solibro achieved a world record conversion efficiency of 13.4% with mass-produced copper indium gallium diselenide (CIGS) modules.

Prior to joining Q-Cells, Dr. Merz worked for BMW from 1988 to 1995 and for Schott AG from 1995-2007, before starting for himself as management adviser. He brings to Solibro extensive experience from industrial production to the strategic alignment of companies to the positioning of technical products.

Solar Server: Congratulations on reaching 13.4% conversion efficiency with your production-scale copper indium gallium selenium (CIGS) modules. Can you comment on the technology and strategies utilized to achieve this breakthrough?

Dr. Merz: The world record-setting efficiency of our Q.SMART module is based on a robust and high-performance design of the materials and the structure. We focused on a complete work control of separation technologies and an evolutionary approach to optimize performance, including all of our production steps.

In my point of view it is the combination of some splendid ideas of the design team and the persistent work of optimization in operation.


Solar Server: Now in terms of CIGS as a technology, what are some of the specific advantages of this material?

Dr. Merz: Due to the monitoring of applications in the field, it is proven that we achieve high efficiency, even at the difficult conditions, for example east-west orientation of the application, and high temperatures. For example, Q.SMART, our CIGS module, is a top performer at a third-party test facility in Alice Springs in Australia, and there we have extreme climate conditions, and there we out-perform all other kinds of modules.

And furthermore, we have with our Q.SMART modules the light-soaking effect, which means after the start of operation of our modules, they increase the yield to approximately 2.5%. That means our customers get more yield than they buy. And in my point of view, those are big advantages for the CIGS technology and thus our Q.SMART solar modules.


Solar Server: Some industry analysts have suggested that CIGS has the strongest potential among thin film technologies for dramatically increased efficiencies. What future do you see for the technology?

Dr. Merz: I am convinced that the technology has a bright future, seeing all the given potential. Have a look at the efficiency. We now have a Q.SMART module with a total area efficiency of 13.4%. And this module wasn't made in a lab but is coming out of our industrial-scale production lines. And that we have already achieved efficiencies up to 16.7%.

My point of view is that this shows that the potential is very keen and I am confident that we will be able to transform the lab results into production-scale timely.

CIGS and thus our Q.SMART modules allow in my point of view the highest potential in terms of cost efficiency for any PV technology that is known today. At the end of the day we have to be cost-competitive, and our advantage is that we have with CIGS already the experience with the industrial-scale production.

In 2010 we have become the world's largest manufacturer of CIGS modules. So we see the potential to reduce cost in production. We are sure that there is room to allow our cost reduction solutions to increase in efficiency. And there is the advantage of the yield for non-optimal conditions in terms of what I have already mentioned in terms of east-west orientation, flat roofs, high temperatures and particularly shading. That is in my point of view the most substantial point.


Solar Server: And to follow on that, do you have a coast roadmap or a cost per watt that you are aiming for with your CIGS technology?

Dr. Merz: What we have to do, normally we won't give any cost statements, but what we have to achieve is cost-competitive levels, and we are sure that we will achieve that.


Solar Server: Can you comment on any potential scarcity issues for indium and gallium, and any strategies that Solibro has taken to secure supplies of these materials?

Dr. Merz: What we think is, for the time being, the ratio of the CIGS technology and CIGS modules on the market is rather low. And we talk about some 10% of the global electric power production that consumes, elements may impose supply limitations but it is a very long way to this level.

The learning of the CIGS material is likely to evolve into new semiconductors, exhibiting similar properties as CIGS but made from other materials which are produced in higher volumes.

However, for the next few years, we don't we face any scarcity of the elements.


Solar Server: With so much emphasis on cost per watt, how is Solibro able to distinguish its Q-Smart PV modules from other PV module offerings, particularly thin-film, say First Solar cadmium telluride models?

Dr. Merz: First of all, I guess that we will have the best efficiency cost performance, which is the fundamental basis for PV industry, in addition, the developments aiming at the lowest LCOE, the levelized cost of electricity.

We have higher efficiency, and less production costs that will have to contribute to that. Q-Cells has the potential experience in the industrial-scale production as well as the high-skilled R&D staff in Germany and Sweden with 20 years experience of the CIGS technology.

In terms of the cadmium telluride, we are in efficiency out-performing cadmium telluride even in the potential in the future. Furthermore, we have the advantage of the aesthetic appearance of the modules with our elegant, black-clad surface.

In case of equal cost, it may influence the decision for our Q.SMART module.

Carport at the Frankfurt fair in Germany with an output of approximately 900 kWp; 6.536 Q.SMART modules. Courtesy: Verein Sonneninitiative e.V.
Carport at the Frankfurt fair in Germany with an output of approximately 900 kWp; 6.536 Q.SMART modules. Courtesy: Verein Sonneninitiative e.V.

Solar Server: The modules are quite attractive. Is there anything else you would like to share with our readers regarding Solibro's work with CIGS technology?

Dr. Merz: What I would like to add is, that up till now we have focused on the European market, and what we want to do in the future, in the near future, is to actively approach the U.S. market with our Q.SMART module also. We are certified to the UL1703 standard and have begun selling activities in the US market.

We see great potential in the market segment with commercial and industrial solar installations, as our Q.SMART modules fit a wide range of applications in this segment ranging from rooftop systems, to flat orientation, to carport systems as well as building-integrated solutions.

And we see that due to the aesthetic experience, there will be plenty of opportunity in all applications which will be exposed publicly.

One reference project for our Q.SMART modules would be the rooftop-installation on top of the airport in Venice, Italy. Another great example is the carport at the Frankfurt fair in Germany with an output of approximately 900 kWp. So that is what we are going to do in the American market, because we see great chances there.


Conducted on April 28th, 2011, by Christian Roselund