Home buyers will pay for solar, a new study from Lawrence Berkeley Lab says, but the incentives are important to make it economical.

Examining home sales from 2001 to 2009 in California, researchers at the lab found that home buyers will pay approximately a $5.50 per watt premium for homes with a solar system. That corresponds to around $17,000 for a 3.1-kilowatt solar system, the report stated. (Feast on the full report and the hedonic model reports here.)

The net costs of these systems, after federal and state incentives, came to around $5 a watt. Homeowners, of course, also enjoyed the benefit of power from their panels. Solar, thus, provides a net benefit to homeowners as long as the incentives are factored in. The price for solar continues to plummet, too. Attorney and reader Jason Jungreis just wrote in to say he got solar put on his roof for $3.80 a watt, including federal, state and San Francisco incentives.

The study helps bolster an argument made for years by solar installers and realtors, namely, that solar adds to a  home's price. The study examined 72,000 home sales, and approximately 2,000 of the homes had PV systems. The premiums ranged from $3.90 to $6.40 per watt.

Strangely, the premiums for solar on new homes was lower than the premium fetched for new solar systems on existing homes. Solar systems on new homes only fetched around a premium of around $2.30 to $2.60 per watt. The premiums on systems for existing homes came to $6.70 to $7 a watt. Maybe it was the fact that solar was a standard, and hence less exciting, feature on older homes, or maybe it made the new homes more interesting.

Approximately 2.1 gigawatts of solar have been installed nationwide. Last year alone, 880 megawatts went online in the U.S., stated the report, citing data from SEIA and GTM Research, up from 435 megawatts in 2009. Thirty percent of the 2010 total was installed on residences. California has 100,000 PV systems and 90 percent are on homes.