Encyclopedia

of Home Improvements

*Solar Power, Without All Those Panels*

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 solar power roofing shingles, tiles and other building materials that have photovoltaic cells sealed within them.

The new materials are part of the building itself, not an addition, and they are taking photovoltaics to the next level-an aesthetic one. 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.

A solar power roofing shingle system that would meet half the power needs of a typical California home would cost roughly $20,000 to install after rebates, or about 10-20 percent more than solar panels providing comparable power. The cells have been installed at several demonstration sites, including a home in Bermuda Dunes, Calif. Rather than creating an entire new roof with the solar tiles, the homeowner chose to insert them in his existing roof, replacing about 300 square feet of terra cotta tiles; the job took about four hours, he said.

The solar insert in the roof will generate about 2400 kilowatt-hours of electricity a year, enough to cover a quarter to a third of a typical electric bill.

Installation of built-in solar power is just starting in the United States, where the bulk of the installations were still experimental. But that will change because the construction industry has realized that energy efficient buildings are an opportunity for growth." The market for the building-integrated products looks promising. Much will depend on when the construction and real estate markets began to recover. The best time to install the photo voltaics in terms of cost and design is during building construction.

Solar power roofing shingles, also known as Building Integrated Photovoltaic (BIPV) panels, could become the standard for solar roofing in years to come, displacing traditional solar modules on rooftops, for two reasons: they produce about the same amount of power and, unlike those modules, they are installed flush with roofing shingles or tiles. For a roofer, that equates to a more straightforward installation.

A new PV shingle enables roofs of residential or commercial buildings to become sources of electricity as well as protection from theelements. The PV shingle face is textured to blend and complement the granular surface of conventional surrounding shingles. Each shingle is 12 inches (30.48 cm) wide by 86.5 inches (219.71 cm) long and nailed in place on roof decking over 30 lb. felt sheeting. Electrical lead wires, #18AWG, extend 12 inches (30.48 cm) from underside of each shingle and pass through the roof deck allowing interior roof space connections. Once in place, the sun's warmth helps bond shingles together forming a weather-resistant seal.

InFrance, 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. "In Europe, building-integrated photo voltaics already make up about 3-4 percent of the total solar market. Incentives help homeowners in repaying the systems' costs in five to seven years.

One other quality will be crucial to the popularity of building-integrated solar cells is "Aesthetics." They have to look good.

Back to Topics Page

Contact