When Dow Chemical introduced a svelte new solar roof shingle at the 2010 International Builders' Show in Las Vegas, attendees were intrigued by the promise of an energy-efficient shingle that keeps your roofline intact while slashing electric bills by 40 to 60 percent. Dow officials told Consumer Reports that the Powerhouse Solar Shingle would be available later that year. The sun has risen and set many times since then but finally the Powerhouse Solar Shingle has come to market, although only in Colorado.

Dow's Powerhouse Solar Shingles are designed to integrate seamlessly with regular asphalt shingles, either during new construction or on a roof replacement. Thin cells in the shingles capture sunlight and convert it to DC current which goes to an inverter box, where it's turned into the AC current used to power a home's appliances and electronics. Figure on about 200 to 400 shingles for the average house, costing $10,000 to $15,000 installed, including a federal tax credit that trims 30 percent off the cost of materials. That's a lot more than you'd pay for an asphalt roof, but you could get most, if not all, of the investment back in the form of lower utility bills.

Colorado was tapped as the business incubator for the Powerhouse Solar Shingle because it has extensive inroads into solar power. "Colorado is a national leader in solar energy innovation and job creation," said Neal Lurie, Executive Director of the Colorado Solar Energy Industries Association, in the news release. "We have the right combination of public sector support, private sector commitment, homeowner interest and an enthusiastic community of builders and installers."

Dow says it plans to extend the Powerhouse Solar Shingle rollout to another dozen states in 2012, including Texas and California. Consumer Reports has not tested the shingle, but we do have extensive reporting on solar water heaters.