Friday, December 26, 2008

Brightey Whities

A new laboratory record in LED white light production has been reached.

December 3, 2008--In the ongoing efficiency battle going on between the research labs of the leading high-power white-light LED makers, Cree (Durham, NC) has gained the highest ground, at least for now. The company just announced that it achieved an industry-best reported R&D result of 161 lumens per watt for a white-light power LED.

Cree's tests confirmed that the 1 mm x 1 mm LED produced 173 lumens of light output and achieved its 161 lumens per watt efficacy at a color temperature of 4689 K. The tests were conducted under standard LED test conditions at a drive current of 350 mA, at room temperature. This level of performance is not yet available in production LEDs, says the company.

Such efficiency levels are about ten times that of a standard incandescent bulb, and at least twice that of compact fluorescent bulbs.
One of the things LED lights will give us as research turns into products is the ability to dial in color as well as intensity. Green light for the Christmas tree. Red light for the guy in the Santa suit. Blue light for those days when your mood needs calming.

Right now the prices for LED lights is rather high. About $70 to $120 for a 100 W (incandescent equivalent) light bulb. This is not too bad for places where changing light bulbs is expensive because LED lamps have lifetimes of 100,000 hours which is about 11 1/2 years of continuous use. By the time a lamp bought today needs changing they should cost a lot less.

Cross Posted at Classical Values


Pastorius said...

LED light is highly directional which makes it less efficient at lighting large spaces.

There are some grocery stores using LED's in refrigerator cases now. They look awful. Most of the case is in darkness.

M. Simon said...

Early days yet.

LEDs are used as backlights in LCD monitors and diffusion of the light is rather even.

Bad design is not an indication of bad technology. It is an indication of bad engineering. Not uncommon when a new technology enters a product space that is not used to thinking of how to properly apply something different.

Karl said...

Cree is a leader in the industry. The company is growing through acquisitions, and has increased production in Asia. Long term potential is pretty good, with products that now include street lamps and auto headlights, but the market is still highly speculative, and the stock is volatile, per Valueline.

But I agree with Simon, long term. Cree is an interesting company and leads the LED industry.

Pastorius said...

From what I can tell, LED's have have a laserlike quality and, therefore, have diffusion problems. Therefore, diffusers are needed.

Diffusers lessen the total lumen output. Therefore, LED's will not be nearly as effective as tested in Labs.

That's an observation I make with my eyes. I don't understand the science.

The reason they are used for headlights and stoplights is precisely because they are directional.

I've never seen them used as street lamps.

M. Simon said...

They are used in traffic lights. Despite the higher cost and the diffusion losses their output and life time make them superior to incandescents. Life time is especially important where safety is concerned.