In California's eco-label-minded real estate market, homes topped with rooftop solar panels can, not too surprisingly, fetch a whole lot of extra green in resale value. And, as with most things in life, size — and age — matters.

Building on a 2011 study that explored the effect that residential photovoltaics— recently deemed as the new granite countertops in the home construction industry — have on home resale values, the U.S. Department of Energy's Lawrence Berkeley National Laboratory digs a bit deeper with a new follow-up study titled “Exploring California PV Home Premiums.” The updated study finds that, among other things, the bigger the array, the higher the resale value of a solar-powered home. In fact, for each kilowatt produced by residential solar arrays in the Golden State, a home’s resale value increased by $5,900. With most residential PV arrays producing in the ballpark of between 2 and 5 killowatts, a home with a sizable rooftop solar system could command a premium as high as $30,000.

The study, which examined sales data for 1,894 solar-equipped homes and 70,425 comparable homes sans PV systems that were sold between 2000 and 2009, also found that, in addition to a PV system’s capacity, newness and shininess can make a world of difference. The premium for a solar-equipped home can drop as much as 9 percent each year that the home's PV system has been in operation, a figure that’s quite high considering that, as the San Francisco Chronicle points out, the electricity-producing prowess of an average silicon solar panel declines at a rate of less than 1 percent per year.

Explains Ben Hoen, the study’s lead author and a research associate at Lawrence Berkeley National Laboratory: "The take-away here is the market is showing that PV is valued by home buyers. There could be a green cachet for the PV system that would be over and above the expected price." He adds that the 9 percent drop in value associated with older PV systems is largely psychological: “They might be perceived as older technology, even if they're still producing electricity at the expected rate.”

Hoen and his fellow researchers plan to build upon their existing findings even further for future publications of the study, examining sales data from multiple states outside of California and including data on residential solar leasing programs which prior to 2009 were not a widely available option for homeowners. Nowadays, solar leasing is pretty much the preferred way to go for most folks looking to cut back on electric bills by harnessing clean, renewable energy from the sun.

You can click here to read the study in its entirety.

Via [] via [Co.Exist]

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Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.

Study: Size does indeed matter when selling a solar-powered home
In California, the more kW the merrier when it comes to a solar-equipped home's resale value. But as a new study details, there's also PV ageism at play.