The afternoon sun bears down on Solectron’s manufacturing facility. But 30 minutes after stepping onto the roof’s new light-colored surface, there’s no noticeable rise in temperature.
Come summer, that translates into a surface that’s up to 50 degrees cooler than last year for Solectron, which hopes to reduce air conditioning costs 20 percent to 40 percent.
Solectron, which makes electronics for companies that outsource their manufacturing, is among the first companies to take advantage of the state’s new $40 million Cool Savings Plan.
The program is aimed at conserving precious energy this summer while offering businesses cash to build or resurface flat roofs using reflective materials.
It’s a concept folks in Florida, Arizona and other sun-scorched states have used for years. California legislators are hoping cool roofs will soon be the craze here by offering businesses rebates of 10 cents a square foot for roof replacement.
For Solectron, that equals $15,000 in savings on a $750,000 repair job that it had to do eventually anyway.
“If you can get cash back, why not?” said Bruce Field, Solectron engineering manager. “The roof will actually pay for itself over time.”
Field said he expects a two-to-five year return on the cost of spraying 1.5-inch white insulating foam on the existing roof’s granulated cap sheet. It’s not only a great way to cut air conditioning bills, but spraying the polyurethane foam also avoids the pounding and clawing of a roof repair job that would be disruptive to the 1,300 workers inside, he said. Plus, when the job is done, there’s no old roofing to dump.
The state Energy Commission began pushing the Cool Roofs proposal last fall, but it took California’s full-blown power crisis to get Gov. Gray Davis’ signature. The goal is to save 120 megawatts of electricity this summer.
So far, the rebates aren’t offered to residential owners, but the commission will continue to push for that.
If all commercial air conditioned buildings in California switched to reflective roofs, it would result in an estimated 300 megawatts to 500 megawatts of power savings at peak usage times, said Hashem Akbari, leader of the Heat Island Group at the Lawrence Berkeley National Laboratory.
There’s evidence showing light-colored roofs also last longer, saving businesses even more in the long run, Akbari said.
“It’s not really a new idea. Actually, it’s something we’ve found works a lot better than we thought it would,” said Danny Parker, a research scientist at the Florida Solar Energy Center in Cocoa, Fla. “White tile or white metal produces a 20 percent savings. Even with dark shingles, going from dark to light is a 4 percent savings. It’s a no-cost option with any kind of roofing.”
The percentage saved varies, depending on how much air conditioners are used and whether the reflective roofs are installed on residential or commercial buildings.
Until recently, homeowners have been reluctant to install light-colored roofs, apparently feeling that they aren’t aesthetically pleasing. But now, with the invention of reflective pigment paints, residents can have black roofs that reflect up to 25 percent of the sun’s rays, as much as white asphalt shingles, said Ken Loye of the Ferro Corp. in Cleveland, which produces Cool Colors reflective paint pigments.
The pigments are added to paint that can go on roof tiles, shingles or other surfaces, pushing the paint price up $3 to $5 a gallon. But Loye said the savings in summer energy bills will make up for it.
“It’s cents per square foot,” he said. “Roof temperatures can get over 190 degrees. If we can cool these things off 40 or 50 degrees, we can reflect it off before it has a chance to get in.”