White roofs, aka cool roofs, have caught attention lately as an offbeat but relatively simple and effective strategy for reducing air conditioning costs and greenhouse gas emissions.
The idea is simple: white reflects heat instead of absorbing it. It's also a favorite idea of Energy Secretary Steven Chu, who said "when you're thinking of putting on a new roof, make it white" in his appearance last month on The Daily Show with Jon Stewart (you can watch the video below). Chu added that white roofs costs about the same as traditional black roofs and for those in a warm climate, a white roof can reduce air conditioning costs up to about 20 percent.
When Chu talks white roofs, he cites research from Art Rosenfeld, the commissioner of the California Energy Commission. Rosenfeld calculated that pervasive white roofs and white streets throughout the United States would create a significant reduction in carbon dioxide emissions — the equivalent to getting rid of all cars for 11 years. You can learn more about Rosenfeld and his passion for energy efficiency by watching the second video below.
The New York Times also covered cool roofs in White Roofs Catch On as Energy Cost Cutters.
"We come home on days when it’s over 100 degrees outside, and the house is at 80 degrees,” white roof owner Jon Waldrep of Sacremento, Calif., told The New York Times.
According to research by the Lawrence Berkeley National Laboratory, nearly every state could see significant reductions in carbon dioxide emissions if 80 percent of commerical buildings were converted to have white roofs, even if white roofs meant increased heating demands in winter. You can see how much each state would save in Imagining a Cool-Roof Nation.
So what do you think? Should commercial buildings switch to white roofs? What about for your home? If it meant significant savings in your air conditioning bills, would you choose a white (or lightly colored) roof the next time you need new shingles? Or would that be too much of a color clash? Share your thoughts by posting a comment below.