Three years after Dow Chemical dropped out of the solar shingle business, a reinvented version of its Powerhouse shingle is back on the market under a new license holder. RGS Energy, a company that started selling solar panels in Mendocino County, California, in the 1970s as the Real Goods Solar Company, now holds the license to produce the shingles. The low-profile shingles — called building-integrated PV, or BIPV— are applied directly to the roof deck and can be mixed with asphalt shingles, an installation designed to be less obtrusive than conventional racked solar panels. Dow based its design on thin-film copper indium gallium selenide (CIGS) cells, but the new “3.0” version of the Powerhouse uses silicon cells, according to the company’s website.RELATED ARTICLESTesla’s Solar Roof Has a CompetitorTesla Will Take Your Solar Roof Order NowRooftop Solar Makes Houses Worth MoreCalifornia’s Solar Panel EdictGAF Dives Into the Residential Solar Market Earlier this month, the shingles were named the best energy-efficient product at the International Builders Show in Las Vegas, one of the largest building materials trade shows in the country. Dow faced an uphill battle in its efforts to sell the Powerhouse. The thin-film cells that Dow used weren’t as efficient at generating electricity as silicon-based cells, and the shingles cost more on a per-watt basis than conventional solar panels. Those two problems may have done in Dow’s solar shingle gambit, and RGS could be banking on the greater efficiency of silicon cells to help it get a toehold in the market. There aren’t many companies in the BIPV business. One competitor is CertainTeed, whose Apollo II shingles use monocrystalline silicon cells. Another potential rival is Tesla, but it has been very slow to roll out its glass-topped solar tile after a glitzy launch in October 2016. GAF, the roofing manufacturer, introduced low-profile solar panels called Deco Tech in 2017. RGS touts lower cost In a fact sheet, RGS compared the installed cost of a 4-kW rooftop system with a conventional rack system and the Tesla Solar Roof. The comparison listed the cost of the Tesla roof at $8.14 per watt and the cost of a conventional rack-and-panel system at $4.29 per watt. RGS lists its total cost per watt at $3.89. In the end, the company said, the cost of solar plus roofing would be $23,212 for the RGS system, $27,229 for a rack-and-panel installation, and $55,520 for the Tesla roof. In a written statement, RGS said Dow had selected the company in part because it had been servicing its portfolio of 1,000 solar installations of earlier versions of the Powerhouse. The RGS license runs until 2034. The shingles consist of a base plate and a monocrystalline PERC insert, a design the company said would allow homeowners to easily update the solar laminate with newer technology in the future. The shingles come in two versions, 55 watts and 60 watts each, with efficiencies of 15.6% and 17.1% respectively. The base plate is made in the U.S. and the solar laminate is manufactured in China. Dow had originally hoped the CIGS thin-film collectors would overtake silicon “as the next big solar cell.” But manufacturing gains that would bring the cost down didn’t materialize. By using silicon in the design, RGS hopes to take advantage of improving efficiencies and the benefits of higher volume production. Asked how RGS will succeed where Dow did not, the statement said, “We know the solar industry and have support systems in place, such as sales support and marketing support. We have plans to invest significant dollars in the Powerhouse brand in order to help support our network of customers and generate business with the goal of making Powerhouse a household name.” This post has been updated to correct the RGS market area for the Powerhouse shingle. The company is marketing them in all 50 states and Canada.