ABSTRACT
Electric lighting consumes a significant amount of energy. About 20 to 25% of all electricity used in buildings and about 5% of total energy consumption in the U.S. are used for illumination. Lighting also produces additional heat in buildings, which may be beneficial in cold climate, but generally this represents a significant load on air conditioning systems, the heat from lighting typically accounting for 15 to 20% of a building’s cooling load.
