January 19, 2007 7:59 AM PST

Cheaper LEDs to light a green path?

The future of light is plastic, Cyberlux says.

The company, which specializes in light-emitting diodes, plans to reveal in about four months prototypes of a new style of white-light LEDs that would both cost substantially less to manufacture and provide more light than conventional LEDs.

Combined, the two advantages would enable light fixtures based on LEDs, which are now relatively expensive, to better compete with traditional lamps based on conventional glass bulbs and fluorescent lights, according to Cyberlux President Mark Schmidt.

"We estimate that the cost and efficiency could be better than fluorescent."
--Mark Schmidt, president, Cyberlux

Consumers currently have to pay more than $5 for a basic LED-lighting chip, he said. To be able to use it in a flashlight or lamp, they have to pay another $10 or so for connectors and other parts.

"We estimate that the cost and efficiency could be better than fluorescent," he said. Schmidt, an IBM computing veteran, likened the movement toward LEDs in the light industry to what happened with computers in the 1970s and 1980s.

The new style of LEDs is based on technology licensed from the University of California at Santa Barbara and Rensselaer Polytechnic Institute.

In conventional white-light LEDs, a semiconductor emits blue light. The blue light passes through the phosphor and becomes white light. The phosphor is thin film on a substrate; the substrate has to be placed in intricate proximity to the semiconductor. Positioning the phosphor is one of the more expensive steps in creating an LED, Schmidt said.

In the coming prototype, the conventional phosphor is replaced with a sheet of polymer, which sort of applies itself to the LED, almost like a layer of shrink wrap. The technology was invented by UC Santa Barbara's Steven DenBaars, who has been a big advocate of LED lighting as a way to increase energy efficiency and reduce greenhouse gases, and Nobel Prize winner Alan Heeger. Heeger also helped found solar-technology company Konarka Technologies.

The switch to a polymer does mean that other aspects of the LED must be changed. LEDs emit heat, which can melt plastic. Thus, the LEDs with polymer phosphors will have to be larger than conventional ones so the heat is dissipated over a wider range. Cyberlux's LEDs, however, will last 25,000 to 75,000 hours--fewer than many LEDs can live but more than conventional bulbs can.

Meanwhile, the prototype will have a greater efficiency than conventional LEDs because more photons will get through the phosphor and emerge as white light. Currently, many photons bounce off the phosphor because they hit it at weird angles. "You're basically losing photons in the diode," Schmidt said.

The scattered photon extraction technology from Rensselaer boosts the output of photons. Cyberlux has worldwide exclusive licenses from both Rensselaer and UC Santa Barbara for commercializing their respective inventions in this manner.

Cyberlux will likely license the design of its LEDs to chip manufacturers. The company will then buy LEDs from its licensees and make lighting elements, Schmidt said.

Approximately 22 percent of the electricity consumed in the United States goes toward lighting, according to the U.S. Department of Energy.

To make matters worse, traditional lightbulbs are incredibly inefficient. Only about 5 percent of the energy that goes into them turns into light. The majority gets dissipated as heat. Fluorescent bulbs are much more efficient but aren't as prevalent, particularly inside homes. LED advocates say their devices will beat fluorescent bulbs.

In a speech last year, DenBaars said that if 25 percent of the lightbulbs in the United States were converted to LEDs putting out 150 lumens per watt (higher than the current commercial standard), the country as a whole could save $115 billion in utility costs, cumulatively, by 2025. That would alleviate the need to build 133 new coal-burning power stations, he said.

In turn, carbon emissions in the atmosphere would go down by 258 million metric tons.

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25 comments

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They need to be more careful with these numbers.
It's true that 95% of the energy that goes into a light bulb is
converted to heat. To arbitrarily consider it wasted is foolish.
Remember that in the colder climates, few people would
consider that heat as waste.

Whatever exact amount of energy would have been "wasted" as
heat from light bulbs must now be generated in your furnace or
boiler.

Then in the warmer climates, you'd have to compensate with
additional air conditioning if you're using conventional bulbs.

Perhaps it's a wash overall if you have equal cooling and heating
months in your locality.

You just need to be more careful when you label the heat from
light bulbs as wasted energy. Not everyone lives in California.
Posted by Sparky672 (244 comments )
Reply Link Flag
heat? a waste?
well i agree in part
i personally have a pet turtle and i think he would be rather unhappy if i replaced his lamp with an led lol
but when it comes to my personal lighting i have a floressant lamp and a led one
Posted by WebmasterOfWarStoke.com (15 comments )
Link Flag
Saving energy through LEDs
Hello,

to steer the discussion into a more fruitful direction, we should note down, that by replacing incandescent bulbs with LEDs, energy is saved if and only if:

You have it in a place, where only light, but not heat is needed, which means:

1. All outdoor lighting
2. Indoor lighting at elevated outside temperatures

Additionally, the higher lifespan of LED's , which is up to 60-fold that of an incandescent lamp, reduces litter and saves time and effort to replace it as well as it eliminates downtimes without light.
Furthermore the more evenly distributed wavelength spectrum of LEDs is not so depressing (in my opinion) than high red wavelength fraction light of incandescents.
Posted by jack_ryan (1 comment )
Reply Link Flag
But many of those incandescant bulbs
are in ceiling fixtures, and thus are providing heat primarily to the portion of the room close to the ceiling -- not to the real-world living area. So most of that heat is wasted, absent well-positioned ceiling fans or some other air redistribution system which will of course use additional electricity.
Posted by laremiller (165 comments )
Reply Link Flag
don't neglect convectional air flow
Unless you have little exhaust vents up there, the fact that the
bulbs are near the ceiling will make little difference.

The ceiling might not be the ideal placement for a heat source,
however, warm air will still rise and displace cooler air via some
amount of convection.

So without the hot incandescent light bulbs in ceiling fixtures,
what have you left? Cold air near the ceiling? Nope. The
warmer air in the room will always rise to the ceiling regardless
of what's up there. Without the incandescent bulbs, the average
temperature of the room will be a little lower.

Hey, I'm not knocking the new LED lights... I'd love to use them
during warmer weather.

Just making a point that the energy savings for certain people
during certain times of the year is not what it seems.
Posted by Sparky672 (244 comments )
Link Flag
Energy Savings
Wow...Where do I start? AWESOME!! As to the other posters about incandescent vs. LED the TCO (Total Cost of Ownership) for LED lighting is incredibly lower than incandescent OR flourescent bulbs. btw, Cyberlux is a public company and I will be buying a lot of their stock!!
Posted by vhallman (2 comments )
Reply Link Flag
LED light color still needs much improvement
I am a huge fan of LED lighting. Incredible energy efficiency and bulbs that never burn out, what's not to like? Well, how about so-called 'white' LED's that are an extremely blue version of white. The human eye prefers a relatively warm light with a well balanced spectrum so that all colors are equally illuminated. White LED's cast a horrible light color, glaring to the eye, even worse than fluorescents. Fluorescents themselves have improved in this regard, but they still don't hold a candle to halogen or even a good old incandescent, yet fluorescents are still not selling well even while being huge energy savers. Also, fluorescents are not dimmable. When the LED makers have a light with the beautiful warm spectrum of halogen that is dimmable, they will sell like hotcakes. Until then, all the cost cutting in the world will not make much difference in the general lighting market.
Posted by ArtInvent (374 comments )
Reply Link Flag
Actually...
I very much enjoy the bright blueish white light that comes from LEDs. As a painter I think it helps brighten up rooms and lets me see the real colors of the paints I am using. I don't like the mucky yellow glow of regular bulbs. The light they give off feels dirty.
Posted by coryschulz (326 comments )
Link Flag
There are dimmable flourescents
Just as a point of clarification - there are dimmable compact
fluorescent bulbs on the market. I have been using several CFCs
in my house in areas where they can be left on for several hours
at a time - e.g. outdoors lighting, hallways etc. The energy
savings are amazing and the bulbs themselves last for around
10,000 hours. However, I agree that they are not yet suitable for
all applications. The prospect of super bright LEDs is very
exciting. The bulbs should never burn out and their energy
consumption will be very low. At this time I have several LED
flashlights. The light they emit is rather bluish. I imagine that
within a few years LED technology will advance to the point
where they will be suitable for home use.
Posted by WhyaDuck (6 comments )
Link Flag
RE: LED light color still needs much improvement
The problem isn't just that white LEDs have a garish blue to them. It's also very monochromatic light -- even with the phosphor. It's still almost laser like in the purity of frequencies. This too is straining for human eyes and color receptors. They need not only a shift to yellow, but a broadening of the spectrum.

Still, I eagerly products and advances in this area.
Posted by grbradsk (3 comments )
Link Flag
Energy Savings??
Seems everyone jumped onto the bandwagon on saving s between LED and Incandescent but forgot to look at the original math. If it cost $5 to make the LED and $10 in parts to control it how long would I need to use it to be cost effective compared to my long life flurescent? How can they sell LED flashlights for $3 if the parts cost $15? Think about it before you comment.
Posted by Sir Limey (43 comments )
Reply Link Flag
 

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