From the California Energy Commission’s Fifth Annual Climate Change Research Conference:
“White roofs can cut a building’s energy use by 20 percent and save consumers money,” says California Energy Commissioner Art Rosenfeld. “The potential energy savings in the U.S. is in excess of $1 billion annually. Additionally, by conserving electricity we are emitting less CO2 from power plants,” Rosenfeld added.
If you break it down annually, it’s about $250 per 1,000 square feet. Since 2005, California commercial buildings have been required to have white roofs. Starting in 2009, new residential roofs and retrofit constructions will be required to have “cool-colored” roofs, which reflect a higher fraction of the sun’s rays than current roofing materials of the same color. Most states offer some energy incentive package for white roof adopters, according to a company trying to sell you a white roof.