If you want free electricity from the sun but don't want rows of pool-table-size solar panels spoiling the lines of your roof, there's now an easier, more attractive solar option.

Building-integrated photovoltaic solar power, or BIPV, has taken the ugly and awkward out of residential solar power systems.

Simply put, BIPV is the mixing of solar power cells into materials you'd normally see on a building, such as roof shingles or the UV coating on a window or skylight.

It's most popular application is the solar shingle, where solar cells are glued or mounted to the surface of a common roofing material, such as slate, cement or asphalt. The shingles are then installed like a traditional roof. The solar panels are no longer on the roof; they are the roof.

The technology has been around for about five years, but it's become more popular recently, thanks to declining prices, federal tax credits and state incentives for homeowners installing alternative energy systems.

Homeowners qualify for a tax credit of 30 percent of the cost of a solar power system, up to $2,000. The credit, which reduces the tax owed dollar-for-dollar, was set to expire in 2007 but has been extended through 2008. Most states offer additional incentives, including grants, low-interest loans and state tax deductions.

When combined, incentives can lower the upfront costs of installing a solar power system by 60 percent to 70 percent, says Noah Kaye, director of public affairs with the Solar Energy Industries Association.

The typical American household uses about 10,656 kilowatt-hours of electricity each year, or about 888 kwh per month, which means a 6-kw solar power system would be needed to cover all of that home's electricity needs.

A 1-kw BIPV solar roof system costs about $14,000 before incentives, says Art Rivera, marketing representative for Sunslates, a solar roof tile manufacturer in Sacramento, Calif. At that cost, the typical American family would have to spend $84,000 to generate all the electricity it uses.