This is an excerpt from EERE Network News, a weekly electronic newsletter.
Company Produces Bright White LED Light Source
Lumileds Lighting, a manufacturer of high-power light- emitting diodes (LEDs) for lighting applications, announced in mid-April that it has achieved a record brightness from a white LED, producing 120 lumens of light from a 5-watt LED source. The new device produces four times more light than the company's previous white-light LED, and the company claims it is the brightest white LED produced to date. For comparison, a 60-watt incandescent bulb produces about 900 lumens of light, so eight of the new white LEDs could be combined together to replace one bulb. That wouldn't save much energy — using about 40 watts, where a compact fluorescent bulb would use less than 20 watts — but it shows that it is possible to produce white-light LEDs at a brightness practical for use in lighting. See the Lumileds press release.
As solid-state devices, LEDs have long been recognized as efficient light sources with extremely long lifetimes, but were limited in brightness and in color choices. A breakthrough in LED technology in recent years led to the development of brighter LEDs and new colors like red and yellow, allowing them to be used in new applications, such as traffic lights. These new LED traffic lights have caught on quickly — in March, for instance, the California Energy Commission (CEC) reported that more than one-third of the traffic intersections in the state now feature LED traffic lights. See the March 14th press release on the CEC Web site.
Despite the success of LEDs for traffic lights, the white-light LED — a light that could be used for room lighting or reading — has remained the elusive holy grail of LED lighting, which is why the Lumileds announcement is significant.
Researchers at DOE's Sandia National Laboratories announced in mid-April that they are also pursuing the white LED goal. The Sandia team expects to eventually produce a white LED that uses half the energy of compact fluorescent lights, which would be one-quarter the energy use of the current Lumileds product. See the Sandia press release.
The Sandia team has also established a new Solid State Lighting Web site.
Rensselaer Polytechnic Institute's Lighting Research Center (LRC) also has a Solid-State Lighting Program and provides extensive information on LED technologies. See the LRC Web site.