SUN ON THE ROOF

Solar Power, Without All Those Panels
Annie Eisenberg, September 26, 2009 (NY Times)

"The main way for homes to harness solar power today is through bulky panels added to the rooftop or mounted on the ground…But companies are now offering alternatives to these fixed installations, in the less conspicuous form of shingles, tiles and other building materials that have photovoltaic cells sealed within them…

"…[C]alled building-integrated photovoltaics…Companies are creating solar tiles and shingles in colors and shapes that fit in, for example, with the terra cotta tile roofing popular in the Southwest, or with the gray shingles of coastal saltbox cottages."

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"SRS Energy…is making curved solar roofing tiles designed to blend in with Southern California’s traditional clay tiles…A solar tile system that met half the power needs of a typical California home would cost roughly $20,000 to install after rebates…about 10 to 20 percent more than solar panels… U.S. Tile…a maker of clay tiles, will be selling SRS’s Solé Power Tiles …It will be taking orders perhaps as early as November for shipment in January… SRS Energy buys the photovoltaic cells that cover its roofing from United Solar Ovonic, a maker of flexible solar modules…[and] bonds the silicon cells to the curved Solé tiles, which are made of the same basic material as car bumpers…

"The cells have been installed at several demonstration sites…Rather than creating an entire new roof with the solar tiles, [one homeowner]…chose to insert them in his existing roof, replacing about 300 square feet of terra cotta tiles; the job took about four hours…The solar insert in the roof will generate about 2,400 kilowatt hours of electricity a year, enough to cover a quarter to a third of a typical electric bill…"

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"A different solar material for the roofs and sides of buildings is being produced by Global Solar Energy…Atomized layers of a photovoltaic coating called CIGS are deposited in layers on a thin sheet…Crystalline photovoltaic cells, the same type as in fixed panel installations, are used within the ceramic tiles available from, among others, the Italian company System Photonics. The cells are held in place and sealed from moisture by a clear plastic protective layer made by DuPont…The tiles come in 13 colors…[B]uilt-in solar power [is] just starting in the United States, where the bulk of the installations [are] still experimental. But that will change…[T]he market for the building-integrated products [is] promising…[but depends] on when the construction and real estate markets…recover. The best time to install the photovoltaics in terms of cost and design is during building construction…

"…[G]overnment subsidies [could] speed adoption of building-integrated photovoltaics in the United States, as they already have in Europe…In France, Germany and other countries, building-integrated solar markets are growing quickly because of subsidies and programs that pay homeowners for the electricity they generate and feed back to the power grid…[T]he incentives help homeowners in repaying the systems’ costs in five to seven years…[Experts believe aesthetics also] will be crucial to the popularity of building-integrated solar cells…"