• Print

Nanosolar CIGS, revisited: ‘We’re not competing with each other, we’re competing with crystalline’


Tom Cheyney
Tom Cheyney
Tom Cheyney, former senior editor of PV-Tech and Photovoltaics International, is now chief curator of SolarCurator.com and director of Impress Labs’ solar practice.

Nanosolar, one of the more controversial thin-film PV players and the subject of some heavy-duty blogging from yours truly in 2010, has been back in the news in recent weeks. First, the printed copper-indium-gallium-(di)selenide company updated recent conversion efficiency gains and manufacturing capacity plans, signed a panel warranty insurance policy with Munich Re, and joined PV Cycle as part of its sustainability efforts. Then, the San Jose-based firm said it had inked (pun intended) a significant module supply deal with three of its European-based partners—Belectric, EDF Energies Nouvelles, and Plain Energy—that calls for the provision of up to a gigawatt of utility-scale panels over the next three to six years. Although I reported some of what Nanosolar’s Geoff Tate and Brian Stone had to say in the PV-Tech news story about the supply agreement, here are some more nuggets from our lengthy phone conversation. 

When I asked Stone about the amount of influence the three partners had on the product design of Nanosolar’s Utility Panel (yes, the generic-sounding term is actually a Brand Name), he said it was “significant.” The Euro trio offered feedback on “the size of the panel, its electrical characteristics, its lower open-circuit voltage, its higher currents, and on the 1500 system volts. They had an influence on the edge connectors and the upper corners of the panels.

“We get alot of feedback, under nondisclosure agreements, on how to improve our panels. Their influence in the 2006-2008 timeframe has come to fruition as we make more panels and enter volume manufacturing.”

The company is eagerly awaiting test data within the next few weeks from a number of sources, including a six-month report from TUV Rheinland’s outdoor test facility in Tempe, AZ, another study from ZSW in Germany, and final results of CIGS solar cell characterization work from the good folks at Fraunhofer ISE, according to Stone. Nanosolar will also have Black and Veatch update a 25-year reliability study originally conducted last year, once more of the field data (including some from the Solar Energy Center near Orlando, FL) come in.

The company’s VP of worldwide sales and marketing did share some intriguing findings from one test partner.  

“We recently finished a study with ZSW. We’ve had up to 1500 hours of damp heat, at 1500V, so 1500V is applied to the positive terminal in the chamber. Our panel’s performance increased by 6%, which was not expected. ZSW has never seen a panel increase like that under that many hours of damp heap and at that system voltage,” he claimed.

He also revealed that the performance of the 1.1MW system operating at a landfill in Luckenwalde, Germany, could be better. “A lot of those panels were preproduction, and we’ve made many improvements on performance and reliability. For that project, the performance is good but it’s not great.”

Stone explained that if one were “looking to characterize the performance of the Nanosolar Utility Panel, in many ways it performs similarly to a crystalline panel. We’re currently at about 80% performance ratios, and we believe that as we get to 12% and 13% panels, we’ll get those performance ratios up to 83%, 84%. It depends on irradiance and temperature but the temperature coefficient today is negative 0.45 degrees K and we’ve got a path to negative 0.4 as we start shipping 12% panels in the first quarter of 2012.

“The low-light performance looks similar to crystalline panels. We’ve got a really low series resistance with our panel and our cells, so that gives us the ability to get to higher efficiencies than cadmium telluride. The downside of having a lower series resistance is that at 0.2 suns, we don’t go up in efficiency, but we lose the same amount of efficiency as you would see with a crystalline panel.  Our panel is not really characterized electrically similar to amorphous silicon or cadmium telluride, it looks more like a c-Si panel performance wise, and I think you find that’s the case with a lot of CIGS.”

Speaking of CIGS, Stone said that Nanosolar panels “don’t look like Solar Frontier panels in regard to light soaking. Our light-induced degradation is right around zero, certainly within warranty tolerance, plus or minus 2% off the production line.  

“What Geoff, Eugenia [Corrales], Dave [Jackrel], and the team have worked on really hard over the last year is really achieving the stability in terms of panel power. We think that going up 7% or going down 7% in panel power is equally bad, because it shows instability in the power output.”

After Stone’s update and tutorial, CEO Tate offered some background and insights into current and future expansion plans.

“We’re in a building of which we were occupying half,” he said. “At the end of last year, we rewrote the lease with our landlord to take over all of the rest of the building, to double the size of the manufacturing area.”

“The choice that we faced was, with the current expansion, we could squeeze into the space that we had but when we looked at planning for the future and for growing rapidly, it made a lot more sense to take over the other space and lay out the factory for 250MW. It made it much easier to flow the materials properly, and we’ll be in a better space in the long run, even though in the short run we have to take on a little more rent.”

But the company won’t be pausing long to catch its collective breath. “We see the expansion to 250MW coming very close on the heels of the current expansion,” Tate explained. “We always want to make the tradeoff for what’s right in the long run. With all the tools that are coming in now, they’re being dropped in place for a 250MW factory.”

Since the first full CIGS cell production line will be rated at 115MW, I wondered how Tate and Co. would reach 250MW, since the numbers didn’t quite pencil out.

The answer, like with any self-respecting, First Solar-emulating thin-film (or crystalline, for that matter) PV manufacturing concern, lies in higher conversion efficiencies. As he noted, when Nanosolar gets those numbers up to 12% and beyond, it will get a bounce in capacity/run rate as well, and that 115MW will become 125MW, and the two lines combined will add up to 250MW.

The piece of equipment on the production floor that differentiates the company from the rest of the thin-film PV pack will have no trouble gobbling up the additional throughput—the highly proprietary roll-to-roll nanoink coater.

“The key to our technology is not that we’re CIGS, but that we’re printing,” Tate told me. “CIGS is good but printing is what allows us to have a much lower cost structure than any other company in this space.”

(Speaking of cost, Greentech Media reports that Nanosolar said it will get below a buck a watt in manufacturing costs by the end of this year, hit the low $0.80s or high $0.70s by late next year, reach the $0.60s in 2013, and dip under low $0.60 per watt in 2014.)

“We love the coating tool because it’s cheap and it has huge capacity, and it’s why we’re going to have lower costs than anyone else,” he explained. “Even at 250MW, it will be idle half to two-thirds of the time; an optimum scale for us with this technology will be an even bigger factory than 250, but 250 is the size of this building. When we build our next factory, our current tentative plan would be to build a 500MW factory, and it would keep the coaters fully occupied, with even more efficient use of the material.”

The next factory? It turns out the Nanosolar team is already starting to think about the next next round of expansion—and keeping the crown jewels in Silicon Valley for the foreseeable future.   

“Last year we surveyed this area (in south San Jose), and we confirmed that there are buildings available where we can put our next factory,” he said. “We haven’t leased a building but we have confirmed multiple buildings in the area that are a short drive from here that can meet our needs.”

Nanosolar already has an international production footprint, with its large plant in Luckenwalde outside Berlin, where the CIGS cells processed in San Jose are sent to be assembled into Utility Panels. At one time, during the company’s Roscheisen era (for Martin Roscheisen, Tate’s predecessor and noted hyperbolist), the panel factory was claimed to have a nameplate of 640MW.

The current CEO cagily noted how some companies “play this ratings game, where they look at how much square feet they have as opposed to the equipment.” The Berlin plant “can handle all the production we have in our plan right now. It’s [capable of] a 100MW plus run rate. We have plenty of room in our factory in Luckenwalde: I don’t know if we’ve recranked the exact numbers, but we have room for a lot more capacity…and we have room on our site to build another building, if we need to.”

Before Nanosolar expands significantly in Luckenwalde, it may decide to join the “distributed manufacturing” trend, in which module production is situated close to where customer demand is—like the southwest US—instead of shipping heavy glass products halfway around the planet.

“Our current thinking is when we put a chunk of capacity in is, we’ll put it in the US,” said Tate. “We haven’t picked a site, but it’s on the planning horizon.”

All that these ambitious plans require is, of course, lots of lucre. The chief exec pointed out the company has “all the cash we need to execute on the plan we’ve laid out, to be in the 100MW plus range next year.”

“We expect to be in the cash-flow positive range early next year, which is excellent, but this is a business where we want to and need to grow quickly to meet the needs of our customers. We expect to raise money to allow us to go to a 250MW production run rate and are already beginning discussions with investors, but are not raising the money right now. We’re laying the groundwork for financing late this year or early next year, so we can double our production to 250MW and keep doubling or tripling from there.”

As for chatter about Nanosolar “going public,” that noise would be premature, according to Tate. “We’re not ready to talk about an IPO now. When things are right, we’ll go public. We’re going to have a very large company very quickly. We are very well-positioned…and won’t have problems raising capital, based on the execution of our plan.”

In true “rising tide carries all boats” fashion, the Nanosolar boss said the growth of other CIGS companies is a good thing.

“It makes people more receptive to CIGS than if we were the only one. We don’t really see ourselves competing with those guys. What our customers tell us is they want more thin film. We can’t grow fast enough to meet the demand, because people believe thin film is where the future is.

“Every megawatt we ship or Solar Frontier ships will come out of crystalline silicon sales; we’re not competing with each other, we’re competing with crystalline.”


  • Photovoltaics International 29th Edition

    Forecasting the evolution of a young, dynamic industry is by definition an uncertain business, and solar is no exception. Rarely, if ever, do the numbers broadcast by any of the various bodies involved in the PV prediction game tally, and even historical deployment rates remain the subject of hot debate. The paradox is that getting forecasts broadly right is going to become increasingly important over the next few years, particularly for those involved in producing the equipment that will support whatever levels of demand come to pass.



Solar Media


We won't share your details - promise!