Scott Siegal, owner of Maggio Roofing, in Takoma Park, Md., figured that if anyone should be installing solar panels on the roof of a house, it is the company replacing the roof. That conviction hardened when he started looking at solar power installations in the Washington, D.C., area where his company works ? many were rack-mounted panels installed on roofs that would need to be replaced soon enough anyway. "Why would you install something that's supposed to last 25 years on top of a roof with a life expectancy of 10 years?" he asks.

Incentives Boost Solar Appeal

Siegal wanted to sell customers a roof replacement combined with a solar system. Local and federal incentives helped make that possible. Earlier this year the District of Columbia launched REIP (Renewable Energy Incentive Program), a rebate program for building owners who install solar electric systems. REIP plus the federal tax credits available under the American Recovery and Reinvestment Act (ARRA), Siegal says, made rooftop solar systems affordable. Up-front costs are reduced, as is the time it takes for homeowners to see payback on their investment. And more municipalities are offering incentives for installation of either solar hot water heaters or solar electrical systems.

Photovoltaic Laminate

Rooftop solar electrical systems come either as crystalline panels installed on racking or as photovoltaic shingles or laminate integrated into the roof. Crystalline panels are more efficient on a per-square-foot basis, but looking at what manufacturers of all types had to offer, Siegal went with a thin-film laminate photovoltaic system. Maggio Roofing teamed up with an electrician to install the system on top of re-roofs, typically either membrane or metal. So far this year the company has sold about 25 re-roofs with solar.

For D.C. residents installing solar electrical, the most substantial incentive comes in the form of a rebate check through REIP. The amount of the check is determined on a per-kilowatt basis. (For details go to The system must be grid-connected and installed by an approved contractor.

Residents could get as much as $9,000 back on their initial investment in a solar electrical system at the rate of $3 per watt for the first 3 kilowatts of installed capacity. Add to that 30% of the cost of the job in the form of a tax credit under the ARRA and a $45,000 project ? to install a new membrane or metal roof, plus a flexible, thin-film photovoltaic laminate on top of it ? will run about half that price.