Wednesday, January 19, 2011

'Green asphalt' layers cool surface on school lot

The idea of using reflective materials to lower temperatures locally and as a tool against global warming is gaining ground. Last month, the Department of Energy installed a "cool roof" on one of its buildings, a white-colored coating that replaced a roof in need of replacing. A cooler roof can mean a 10 percent to 15 percent reduction in the cooling load, DOE under secretary Cathy Zoi said in a blog. In aggregate, cool roofs (PDF) can make a significant difference on energy use and act as a way to reflect heat back into space, according to researchers at the Lawrence Berkeley National Laboratory. They estimated that if just over three quarters of commercial buildings were covered with cool roofs, the reduction in air conditioning load would be the equivalent of taking a millions cars off the road, or 6 million metric tons of carbon dioxide per year, Zoi said. Lawrence Berkeley now is working with the Oak Ridge National Laboratory and he California Energy Commission on the Cool Colors Project to research and develop cool-colored roofing materials. Emerald Cities' Roese said she was inspired by the cool roofs' work at Lawrence Berkeley National Labs to make a reflective material for pavements. More>