Page - 45 - in Water, Energy, and Environment - A Primer

industrialplants.TheprogramnowservesnotonlytheUSbutalso the European Union, Canada, Iceland, Japan, Liechtenstein, Norway,SwitzerlandandTaiwan. 5.5.6 The lighting revolution An important example of improving energy efficiency is the revolutionary change in lighting technology that is currently underway. This involves the replacement of traditional incandescent light bulbs with much more energy-efficient and longer-lasting light-emitting diodes (LEDs). It is a significant revolutionbecause lightingaccounts for about20%ofelectricity consumption in theUSand19%onaglobalbasis. It is estimated thatLEDusecouldcut theUSnumber inhalfby2030. The revolution actually beganwith the introduction of CFLs (compact fluorescent lamps) which had been gaining market share for several years until they were displaced in turn by LEDs.The reason for this displacement is explainedbelow. Let us start with a few words about lighting technology. An incandescent light bulb, the most common type today in households and the least expensive to buy, produces visible light fromaglowing filamentwire (made of tungsten) heated to a high temperature (several thousand degrees) by an electric current passing through it. It was not invented by Thomas Edison (many earlier inventors had experimented with hot Figure5.3 EnergyStar labels (Source:U.S.DepartmentofEnergy). Energyoptions 45