Light engines as a future high efficiency lightbulb

[pm]

I was reading through the latest issue of the EETimes over lunch and an article on page 14 caught my eye. It talked about work at the Sandia and Los Alamos National Laboratories on using quantum dots to create light efficiently. A conventional incandescent lightbulb has an efficiency of about 8% - only 8W in a 100W lightbulb is converted to light, the rest is given off as heat. The prototype that the teams made has a conversion efficiency of 55% and they believe that a commercial product could achieve close to 100% efficiency.

EETimes article
The website of the team's working on it

I found the article to be intriguing and thought that I'd pass it along.

 

[CTho9305]

edit: never mind.

 

[Geniere]

Yeah - Quite a "big deal" I think.

 

[zephyrprime]

normal fluorescent lightbulbs are less than 10 percent efficient. But in the future, light engines currently

How can a fluorescent bulb be only 10% efficient if an incandescent is 8% efficient? Seems to me that is an incandescent is 8% efficient, a fluorescent would be about 30% efficient.

 

[imported_Nail]

Fluorescents are about 30% efficient.

And whatever happened to LED's?

 

[AnthraX101]

Originally posted by: Nail
Fluorescents are about 30% efficient.

And whatever happened to LED's?

LEDs provide a highly focused light that is usually not appropriate for ambient lighting. They are pretty efficient though.

AnthraX101

 

[pm]

Originally posted by: zephyrprime
[How can a fluorescent bulb be only 10% efficient if an incandescent is 8% efficient? Seems to me that is an incandescent is 8% efficient, a fluorescent would be about 30% efficient.

Good point. They must have meant incandescent.

And whatever happened to LED's?

They work well in traffic signals because you can use the primary color of the LED without having to use filters as you do on incandescent. And they are very long life. They are also good in small applications like nightlights, flashlights because incandescent lights are very inefficient when they are small. But the current white LED's are not as efficient as compact flourescents or regular flourscents and the cost a lot more. Most of the white LED's out use a blue LED and a phosphorescent screen to use blue light to generate white light. Blue LED's are not among the highest efficiency LED's (although they are getting better), and the two-stage process reduces the efficiency further. I found a really good table the other day searching with google, but I can't seem to find it now.

 

[Mark R]

These new light sources could be very valuable in terms of energy conservation, as lighting represents about 20% of electricity consumption.

normal fluorescent lightbulbs are less than 10 percent efficient

Yup. That's about right. Typical fluorescent lights are about 8-10% efficient. You can get slightly higher with high-frequency electronic control gear and high efficicency tubes. Incandescents are a lot worse: between 2-3%

1Watt of visible light energy is about 550-600 lumens. A typical 100 W incandescent bulb produces about 1200 lumens.

Low pressure sodium lights (yellow orange street lighting) are about 3 times as efficient as conventional fluorescents and can achieve 30-35% efficiency.

 

[DrPizza]

I recall some sort of sulfur light, where they bombarded sulfur with microwaves to generate light... I wonder what the efficiency on those was? IIRC, they were expensive and gave off a LOT of light for their size. (and keeping the size in mind, and dissipation of heat, that's why I wonder about their efficiency)

edit: found it... yes, quite efficient

Spectral Qualities: Almost 75% of the energy emitted from the bulb is emitted as light in a full-color continuous spectrum. (About 50% of the energy emitted by a metal-halide lamp is in the form of light, whereas the corresponding value for an incandescent lamp is about 10%.) Fusion says that the technology allows for lamps with a correlated color temperature in the range 4000?9000 K. The lower temperature will be achieved at the cost of reduced efficiency.

(however, the initial lights were 5.9kW, not quite the size you'd use in home applications..)