Cree demo LED bulb turns up dial on efficiency
A prototype bulb has an efficiency, as measured by lumens per watt, that is more than double commercial CFLs and LED bulbs available today.
Cree has made an LED light bulb designed to show the industry what can be done in the pursuit of energy-efficient lighting.
The company yesterday unveiled a demonstration LED bulb that meets the stringent efficiency requirements of the L Prize, a Department of Energy-sponsored contest. Cree, which makes LED light sources used in bulbs and light fixtures, doesn't plan to release the prototype as a product.
The bulb, which Cree is calling the 21st Century Lamp, gives off more than 1,300 lumens, or more than a 75-watt incandescent light, and consumes 8.7 watts. It's shaped to give off even light, making it suitable for all sorts of applications, rather than just spot lights or ceiling lights placed in recessed cans.
The color rendering index, a measure of light quality, is over 90, which is relatively high for LEDs, and the color temperature can range from a cooler white light to more traditional yellow color.
This bulb from Cree's labs follows another
"We calculate that if fully deployed, LED lighting at 150 lumens per watt could bring a 16.5 percent reduction in the nation's electric energy consumption, returning it to 1987 levels," said Cree co-founder Neal Hunter in a statement.
For comparison, Lighting Sciences Group has a 60-watt equivalent that consumes 13 watts for a rating of 65 lumens per watt. A 75-watt incandescent bulb performs at about 14.6 lumens per watt, according to Cree. EnergyStar-rated compact fluorescent light (CFL) have lumens per watt ranging from the mid-50s to mid-60s.
Cree engineers adopted a novel shape to get the even light and efficiency it was shooting for. Instead of a round bulb, the lamp is shaped like a cylinder. And like all LEDs, it has a heat sink below the light sources to wick away heat and improve the product life.