At the time Ohashi had to approach two suppliers to get the solar roof he wanted, but today that would be unnecessary. As solar continues to grow in popularity, more roofing manufacturers are integrating cells with their product, creating one-stop shopping for design professionals.
The idea of integrating solar with building products is not exactly new, but its use had been limited until recently. So-called building-integrated photovoltaics (BIPV) are thin-film solar cells that have been applied to a material, such as glass. Because of manufacturing advancements, roofing companies are integrating BIPV into their products and supplying them off-the-shelf. The technology is unobtrusive in appearance, and the materials are less expensive than traditional solar panels and offer flexible installation.
all systems go
At the International Buildersâ Show in January, Valley Forge, Pa.âbased CertainTeed Corp. entered the solar roofing category with EnerGen, a system that integrates Uni-Solar thin-film laminates from Energy Conversion Devices in Rochester Hills, Mich. The black solar shingles seamlessly merge with the manufacturerâs asphalt, so once theyâre installed, they sit flush with the roof and differ only in color.
sun spots

Which other states offer great solar incentives? Unfortunately, thereâs no such ranking. âThereâs not really a single report that addresses thisâat least not one that gives what I would consider a âgoodâ or âaccurateâ answer,â says Amy Heinemann, a policy analyst at the Database of State Incentives for Renewables & Efficiency, an ongoing project of the DOE-funded North Carolina Solar Center and the Interstate Renewable Energy Council.
Even so, certain data gives you a good idea. âBy looking at installed capacity by stateâeither cumulative or for 2009âyou can get a sense of where the best solar markets are in the U.S.,â Heinemann notes. The following list, compiled by the Interstate Renewable Energy Council, shows the top 10 states for grid-connected PV capacity installed in 2009, measured in megawatts.
1. California 212.1
2. New Jersey 57.3
3. Florida 35.7
4. Colorado 23.4
5. Arizona 21.1
6. Hawaii 12.7
7. New York 12.1
8. Massachusetts 9.5
9. Connecticut 8.7
10. North Carolina 7.8
âCertainTeed is transforming a niche technology into a product that is more accessible to the building industry and, therefore, a broader range of homeowners,â said Guillaume Texier, president of the companyâs roofing division, at the productâs launch. âEnerGen is the first step in what will be a comprehensive portfolio of photovoltaic roofing products for residential and commercial applications.â
But CertainTeed is not the only the company taking this approach. Midland, Mich.âbased Dow Chemical Co. also is throwing its hat in the ring with Powerhouse Solar Shingle, a thin-film PV system that, like EnerGen, is woven into standard asphalt.
While asphalt is the recent comer, concrete tile manufacturers got into the solar act first. Eagle Roofing Products in Rialto, Calif., partnered with Suntech Power to produce the Eagle Solar Roof with SolarBlend, a system that maintains a similar design aesthetic as a tile roof. And Corona, Calif.âbased US Tile, which has partnered with SRS Energy, claims that its SolĂ© Power Tile system was âthe first truly integrated solar solution in the nation.â Designed to seamlessly meld with the manufacturerâs Mission profile clay tiles, SolĂ© installs like a standard piece of tile.
For architects who arenât interested in asphalt, clay, or concrete but still want integrated solar, metal companies offer a solution as well. Last year, Custom-Bilt Metals in Chino, Calif., unveiled FusionSolar, a thin-film solar laminate integrated with standing-seam metal roofing. The system comes with all the necessary components, detailed schematics, and specifications for wiring and electrical components that an electrical subcontractor needs for installation. And back in 2007, EnergyPeak (a partnership between CENTRIA Services Group, and Uni-Solar) introduced a solar-integrated standing seam product.