Remember when Mom used to nag you about turning off the lights when you left the room? Someone wasn’t heeding that advice last year, as a new report conducted by Navigant Consulting and funded by the Department of Energy found that lighting consumed almost 8% of the total U.S. energy consumption in 2001.There are more than 7 billion lights in use across the country.

“The U.S. Lighting Market Characterization, Vol. I: National Lighting Inventory and Energy Consumption” estimates the installed base of lamps in the United States and their energy consumption. The study found that commercial buildings used the largest share of lighting energy at 51%, followed by residential at 27%, industrial at 14%. Incandescent lamps were the highest energy user.

Navigant is working with the Department of Energy to identify opportunities for increasing energy conservation in high-priority areas identified in the lighting inventory.