Nearly 20 percent of all electricity used in the United States is used for lighting homes, buildings, factories, and streets. According to a recent U.S. Department of Energy analysis,lighting accounts for more than 40 percent of commercial sector electricity consumption in the United States, a total of 391 TWh/year [U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Building Technologies Program. 2002. U.S. Lighting Market Characterization, Volume 1: National Lighting Inventory and Energy Consumption Estimate.Prepared by Navigant Consulting. Washington, D.C.: U.S. Department of Energy]. Offices, retail, and warehouses are the largest contributors to commercial lighting energy use (see figure), but grocery stores, health care facilities, and retail stores are the most energy-intensive due to their long hours of operation and bright lighting in most areas. In all commercial building types, attention to the selection of the lighting system can result in lower energy consumption and lower operating cost, with minimum additional cost and equal or greater lighting quality than conventional lighting. Side benefits include improved building appearance and aesthetics, and improved building asset value (for both owner-occupied and owner-leased/revenue-producing space). Many of the recommendations we offer are commonly used in everyday construction in regions where energy codes and expensive electric power has forced more efficient design.
