Houses having a white rooftop may seem too mediterranean to some, but I guess the Greeks knew what they were doing when they painted them so. A recently published article in Newsweek shares Bill Clinton’s advices on how to reduce unemployment in America. One of them is painting black rooftops in white.
In addition to creating new jobs for those who would actually do the repainting, the idea would definitely reduce the energy used by air conditioners throughout the country.
Clinton says that “A big percentage of the kids have been able to parlay this simple work into higher-skilled training programs or energy-related retrofit jobs. (And, believe it or not, painting the roof white can lower the electricity use by 20 percent on a hot day!)”
Currently available solar reflective white dyes can reflect up to 90 percent of the incoming sunlight, while a black tar rooftop reflects only 20 percent. The rest is just providing heat to the building and adding dollars to the power bill.
A specially-designed tile has actually been invented that, on hot days, turned into white and in winter turned into black, with the use of a thermally-responsive dye. We wrote about it a while ago.