There may be a growing number of solar application ideas that die off before going mainstream, never having tapped enough technology, financial backing, and market savvy to last. But it seems solar roof shingles is not one of those. Dow withdrew from the market*, but Exasun and Tesla moved in. Now, there’s also a smart new set of patent-pending thin-film CIGs solar shingles being offered by Sunflare Solar, based in La Verne, California. The company refers to the cell technology as Capture 4.
The company began offering commercial versions of the shingle two months ago for both flat TPO-covered roofs and for pitched metal roofs, including carports. Within 18 months, the residential version will be available, once UL certification is complete. All three shingle versions, based on a four-cell, 180 watt design, have been on display this week at Solar Power International 2018 in Anaheim, California.
“We started production last year and are launching now,” says Elizabeth Sanderson, the chief marketing officer for the company. “We looked around to see what segment of the solar market was underserved and we decided on shingles,” she says.
What is most appealing about the residential shingle design is that it actually looks like a typical asphalt shingle, not something five times as thick, nor obviously a blend of the cells and base material.
“We wanted a shingle that looked and felt like the same thing roofers are used to, so that installation would be fast,” says Sanderson. While some past designs of solar shingles have weighed in at 5 pounds, the Solarflare shingle is only 0.6 pounds, she says.
Because of the low weight of the shingle, loading a roof with bundles is not difficult. “We tested a 40 kW roof install and found that the roof was loaded in just 20 minutes,” Sanderson says. Additional time studies are planned to confirm how fast the shingles can be installed on each type of roof.
The commercial shingles can be fixed to the substrate with double-sided tape or adhesive, and if the metal roof has grooves, those can be used as a default raceway for wire management. There is no roof penetration on the TPO roof, since hold-down hooks can be attached with adhesive where necessary.
While the top edge of the residential shingle is nailed or screwed down just like a standard shingle, a nifty design improvement in solar shingles to date is a snap-together electrical connection on the bottom edge of the shingle. The snaps even look like the ones on shirts.
The raceway for wire combining in the residential design runs along the peak of the roof. For the commercial designs, the company designed a special low half-dome raceway that will avoid any shading.
While the wattage of the individual shingle is relatively low compared with standard solar panels, the final cost of the installed product will be lower, Sanderson suggests. The company also manufactures roughly standard-sized solar panels with a 6 cell by 10 cell configuration, which sell for about 70 cents per watt, she adds.
One performance advantage the thin-film cells have is that they absorb low-level light — at dawn, at dusk, and during cloud cover — better than standard crystalline cells in regular solar panels. “10 percent more energy is generated at dawn and dusk because of better low-light performance, and at midday when temperatures are hottest because of the low temperature coefficient of CIGS,” the spec sheet notes.
General advantages the Sunflare cells have over crystalline silicon cells is that the thin-film cells are 75% lighter and 95% thinner, the specs also highlight. Flexibility is imparted by a 0.127 mm stainless steel backbone in the Sunflare panels.
The waterproof panels are wind and cold proof, do not crack, and withstand high impact.
Roll these features together and top them off with a 90% energy generation efficiency during the first 10 years of life service, with a degradation of only 10% to 80% efficiency over the following 15 years of the warrantied lifetime of the panels.
One interesting non-building application for the Sunflare panels is their use on the roofs of Vistabule teardrop campers for on- or off-road energy supply. The panels also can be used on boats and larger vessels.
Privately-held Sunflare has about 50 employees among its offices in China, Sweden, and the United States.
*Edit: According to Jim Turner of RGS Energy, his company licensed the technology from the Dow Chemical Company in October 2017 and is about to launch the Powerhouse™ 3.0 solar shingle.