LEDs offer numerous benefits due to their mode of operation:
Energy Efficiency,LEDs are highly efficient. In traffic signal lights, a strong market for LEDs, a red traffic signal head that contains 196 LEDs draws 10W versus its incandescent counterpart that draws 150W. Various estimates of potential energy savings range from 82% to 93%. With the red signal operating about 50% of the day, the complete traffic signal unit is estimated to save 35-40%. It is estimated that replacing incandescent lamps in all of America’s some 260,000 traffic signals (red, green and yellow) could reduce energy consumption by nearly 2.5 billion kWh. At the end of 1997, more than 150,000 signals were retrofitted, almost all of them red.
In architectural applications, the greatest penetration of LEDs has been in exit signs, both new signs and retrofits. LED retrofit products, which come in various forms including light bars, panels and screw in LED lamps, typically draw 2-5W per sign, resulting in significant savings versus incandescent lamps with the bonus benefit of much longer life, which in turn reduces maintenance requirements. Some of these products are designed specifically for either on-face or two-face exit signs. Many new LED exit signs are also available, including edge-lit designs. LED products currently make up about 50% of the exit sign market. A study conducted by the Lighting Research Center in 1998 found that about 80% of new exit signs being sold in the U.S. utilize LEDs. Note that most retrofits are restricted to use in stencil-type signs versus panel-type signs.
