July 22, 2002—National retail chains such as Wal-Mart, Sears, Target, and Lowe’s Home Improvement Warehouse have installed “cool roofs,” helping California stretch its power supply during heavy air conditioning-demand months to prevent shortages and higher costs. Almost a third of the electricity used on a hot summer afternoon in California is purchased to keep buildings cool.
A “cool roof” can reduce electricity consumption in any one building by an average of 20 percent. A traditional, heat-absorbing, dark roof absorbs over 70 percent of the energy radiating down from the sun. In California, that translates into peak roof temperatures that range from 150 to 190 degrees Fahrenheit on hot summer days. In comparison, light-reflective cool roofs average 50 to 60 degrees cooler.
Since most commercial buildings in California have low-sloped or flat roofs that are ideal for cool roof applications, the California Energy Commission supports cool roofs as a cost-effective investment in energy efficiency. The California Energy Commission’s Cool Savings with Cool Roofs Program is providing rebates ranging from 15 cents to 20 cents per square foot of eligible roofing to businesses and other entities that replace or resurface their old “hot” roofs with new cool roofs.
For example, Sears has received rebate checks of $21,245 and $13,256 for stores in Burbank and San Diego; Target has received an $8,776 rebate check for a Rosemead store; and Lowe’s has received rebates totaling over $200,000 for stores in such locations as Roseville, Vacaville, San Clemente, Anaheim, Upland, and Burbank.
In addition to energy savings and reduced electricity demand during summer peaks, cool roofs offer other benefits to business owners and the community at large:
- Decreased long-term roofing maintenance and replacement costs;
- Extended life of air conditioning units due to less cycling and operations;
- Improved comfort for workers in buildings and on the roof;
- Reduced air temperatures surrounding the cool building (“heat island” effect);
- Less roofing waste in local landfills.
