White Roofs in NYC.

In New York City, Mark Z. Jacobson, a professor of civil and environmental engineering at Stanford University, has been doing a study on white rooftops for apartment buildings to see if the color change from black would have any kind of affect on keeping the buildings cooler and more efficient. Their findings have been very eye opening. So much that the city is embarking on a push to change as many roof tops as possible to white. The change could have enough of an effect on the downtown area, that it would actually reduce the “heat island effect” that makes the city 5-7 degrees warmer than the actual temperature at night in the summer. In 2011, on the hottest day of the summer, a white rooftop measured 43 degrees cooler than a black roof. That is huge and no doubt will reduce energy consumption for the building.

Source: cleantechnica.com