CertainTeed’s Apollo Photovoltaic Solar Roofing is aimed at homeowners who want solar power without the bulk. These panels are less than an inch thick yet promise to slash 40 to 70 percent off electricity bills in a typical installation. Better known for shingles, CertainTeed, which featured the solar panels at the International Bulders’ Show, designed them to integrate with asphalt roofing and install directly on new or existing roofs.

That means the panels can act as the roofing itself, without shingles beneath. With a claimed 12 watts per square foot, the system’s polycrystalline cells produce power that’s comparable with traditional systems but in a much slimmer package. Unused power flows back to the grid, in effect letting you charge your utility. And because each 100-foot square weighs roughly the same as asphalt shingles, you don’t need the usual roofing reinforcement.

At about $24,000 installed, CertainTeed’s Apollo system isn’t cheap. But with the 30-percent federal tax credit for renewable energy as well as some local and state incentives, it could pay for itself in as little as four years—far less than some solar and wind systems we tested. A leasing option could also make this system a sunnier proposition for some—provided your roof gets enough sun.

—Bob Markovich