Updated: After years of talking about flexible, light-weight solar thin film material that can drape over roofs, manufacturers are finally starting to deliver. SoloPower is announcing on Tuesday that its first flexible solar panel has gotten UL certification, which is required for installation in many U.S. regions.
SoloPower, backed by Hudson Clean Energy Partners, received the certification for its “SFX1,” which is made out of copper-indium-gallium-selenide cells, which represent the next-generation of thin film solar technology. The San Jose, Calif., startup is one of CIGS solar panel makers that are starting to roll out flexible thin films, which they say can lower installation costs by forgoing a need to use mounting systems (for flat roofs). Another selling point is that these thin films can be built into roofing materials.
Just last week, Global Solar Energy, unveiled a flexible solar panel. Global Solar, based in Tucson, will need to get certification for its new product as well. Update: Ascent Solar Technologies, a public company in Colorado, also is launching a flexible CIGS panel (320-watt, 5-meter by 0.6-meter), and the manufacturer plans to show it at a solar conference in Los Angeles in October.
SoloPower plans to make its SFX1 an 80-watt panel that is 0.3-meter by 2.9-meter. It also has engineered a larger, 260-watt version (0.9-meter by 2.9-meter), which is undergoing certification testing now, Tim Harris, CEO of SoloPower, told us in an interview.
“At the end of the day, what customers care about is the total installed cost,” Harris said. “By being light weight and flexible, you can do a whole bunch of things that take out the total installed cost.”
Getting safety and performance certification is an important item on the check list for any solar panel maker, and it’s not just for the U.S. market. UL is one of the testing standards available and most widely known in the U.S., while IEC testing is standard for continental Europe. The boom in the solar market in recent years has prompted testing organizations such Underwriters Laboratories and TÜV Rheinland to set up labs in different parts of the U.S., Asia and Europe.
The majority of the solar panels on the market use crystalline silicon solar cells, which are fragile and rely on glass to protect them. Thin film solar panels, on the other hand, contain ultra-thin layers of alternative versions of silicon or other semiconductors and don’t necessarily need glass. However, the world’s largest thin-film maker, First Solar, sandwiches its cadmium-telluride solar cells in between glass.
CIGS materials can be deposited on glass, metal foil or plastic, but even those made with metal or plastic substrate often are packaged with glass. A lack of adequate materials to protect the solar cells from moisture and other environmental damage has been a big stumbling block, though CIGS solar panel makers say they are finding better solutions these days.
SoloPower can make its SFX1 model with 11.5 percent aperture efficiency, which takes into account only the area on the panel covered by cells. The total-area efficiency is about 10 percent, Harris said. The company has a factory that can produce 10 megawatts of solar panels per year, and it plans to install a second production line of 75 megawatts, with shipping from the new line to start in a year, he added.
Aside from Global Solar, SoloPower will be up against United Solar Ovonic, which has been making flexible thin films using amorphous silicon for years. Uni-Solar’s panels have lower efficiency, at around 7 percent, but it has gotten an early start in the flexible thin film business. Dow Chemical has also said it will roll out roofing shingles with solar cells next year.
Whether these companies can offer the right mix of high-performing products with low prices remains a big question mark, not the least because they will not just be competing against one another but also manufacturers of conventional solar panels.
Some roofing companies have talked about integrating solar thin films into their products, but the market for this type of product is still very new. Johns Manville, a roofing membrane maker, inked a deal to buy Uni-Solar’s flexible panels last year. Instead of building the panels into the membranes, however, Johns Manville is putting them on a layer of insulating material that can then be added onto its roof membrane during installation, said Brad Burdic, who heads the portfolio owner services at Johns Manville. Solar panels, in general, produce heat when they are generating electricity, and that could damage roofs and void warranties.
He added that the U.S. commercial rooftop market hasn’t been great, and noted that some of the utility’s own programs to promote larger-scale installations on flat commercial rooftops, such as the one run by utility Southern California Edison, have create business opportunities for only a small number of companies.
“I would say the business is not robust,” Burdic said. “Several large building owners have participated in the Southern California Edison program for large, megawatt-size projects, but the [deployment] resides with a few building owners and manufacturers.”
However, companies such as SoloPower and Global Energy believe the idea of integrating solar into building materials is a logical step in the evolution of the solar market.
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