The average commercial building electric bill often features a consumption and demand component. The consumption component reflects the amount of electric energy (kilowatt-hours) used, and the demand component shows the maximum demand (kilowatts) during the billing period.
Joel Spira, who founded Lutron Electronics Co. in 1961, invented the first solid-state dimmer in 1959. For decades after, dimmers were largely used to control the aesthetic environment. Only in recent years has dimming become an important part of the energy costs saving debate.