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November 3, 2006 12:27 PM PST
Expert: LEDs could start replacing lightbulbs soon
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Right now, consumers and businesses can buy a light-emitting diode, or LED, that provides about the same level of illumination as an energy-hogging conventional 60-watt lightbulb, Steven DenBaars, a professor of material science at the University of California Santa Barbara, said at the SEMI NanoForum, taking place here this week. A principal advantage of the LED: It lasts about 100,000 hours, far longer than the conventional filament bulb
Unfortunately, the LEDs that can perform this task cost about $60, he said. (Prices vary on the Internet.) But prices have been declining by 50 percent a year, so two years from now the same LED should cost around $20.
"At $20 the payback in energy occurs in about a year," DenBaars said. The rapid return on investment will occur in places such as stores and warehouses, where the light is on through much of the day. A year after that, LEDs will be even more economical for more places as costs continue to decline.
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.
If 25 percent of the lightbulbs in the U.S. were converted to LEDs putting out 150 lumens per watt (higher than the commercial standard now), the U.S. as a whole could save $115 billion in utility costs, cumulatively, by 2025, said DenBaars, and it would alleviate the need to build 133 new coal-burning power stations.
In turn, carbon emissions in the atmosphere would go down by 258 million metric tons.
"Multiply that by three and you get the worldwide savings," he stated. DenBaars then showed a picture of the globe at night. The landmass of the U.S. could easily be picked out by nighttime lights.
"We shoot a lot of light into space that doesn't need to be there," he noted.
Rising prices of electricity, combined with the antiquated nature of lightbulb technology, has prompted several start-ups and large industrial concerns to get into lighting.
Fiberstars, for instance, has come up with a way to replace hot fluorescent tube lights with light-emitting optical fiber in freezer cases in grocery stores. Hewlett-Packard spinoff Lumileds is also producing LEDs for a variety of applications.
LED technology is improving as well. UCSB has created an experimental LED that can put out 117 lumens per watt, while a Japanese company has developed one that can put out 130 lumens per watt.
Getting LEDs to produce white light that is tolerable to humans has also greatly improved. Manufacturers can do it two ways. One is to package red, green and blue LEDs in a way that the combined light shines white to the human eye. The other way is to make blue LEDs and coat them with a phosphor--a luminescent substance commonly used on fluorescent lamps.
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I have just about replaced all of my 60 & 100 watt bulbs with those 13 & 27 watt fluorescent bulbs.
After they tackle efficiency, they have to tackle color so you will all find it visually acceptable to put in your home.
There are many ways to save energy you don't have to wait for LEDs - which are A LOT more than 2 years away from replacing current light bulbs.
Also keep in mind when an LED goes out - you have to replace and entire circuit board and heat sync - not just a lamp.
That is nothing. I suspect someone lost 6 magnitudes or something and the number should be 258 million tons. Otherwise, why bother?
LEDs are terrific but energy saving is already mighty easy with fluorescent lights. Those are super cheap too (less than $1 a piece depending on the type) and fit in regular light fixtures. That's what will have to happen with LED lights too.
Dimming of these compact saver bulbs is an issue although some are made that actually are dimmable. Of course they are so expensive it's not worth the trouble.
What about efficient cooling (solar roof vents)?
And will the LED really be cost-effective? Some of the flourescant GREEN bulbs cost more than 2x the lifespan in incandescant bulbs (remember the startup of the green bulbs uses more power).
I look forward to better home codes, better lighting and I hope, better efficiency.
The problem is of course that 110V (220V) is so conveniently transformed into any DC power you need. Telecom equipment requires DC power because of the backup batteries they use to make the phones ring when the power goes down. So these types of boxes use DC-DC converters. Not that cheap.
I suppose having a 12V net just to power the lights would be nice. Couple of car batteries and solar panels would get you quite far.
You know why?
The LED is WAY TOO EXPENSIVE when compared to Compact Flourescent bulbs.
A 10 watt CF bulb gives out the equivalent of a 60 watt incandescent bulb. I bought loads of CF bulbs on sale at Albertson's one time when there was a promo, a set of 3 CF bulbs costs only $0.99! Regular prices now are less than $1 per CF bulb. Lumen per lumen, LED is less efficient than CF bulbs, last time I checked.
they have to bring the prices of LED bulbs, and fr an equivalent 60 watt incandescent bulb, the LED bulb should be sold for about $3 or less.
CF bulbs currently lasts 5 to 6 years, or 20,000 hrs, factor in terms of present values, the LED which they claim would last 5 times as long as CF bulbs, it should be sold for $3 or less, right now, and not in the future. If they can't do that, that technology is useless compared to CF bulbs!
What if in 4 years LEDs work 10 times better then any other bulb? When the first run flat tires came out they were super expensive. When the first LCD TVs/Monitors came out they were super expensive. Things dont happen overnight so relax.
Of course, potentiometers can be used for dimming and electronics can produce all kinds of programmable color patterns etc...
As far as the incandescent thing goes, they are more efficient than 5 percent (as the article claims) from everything that I've read. Still, they are very wasteful as far as electricity being converted into a good bit more heat than light. I just wish the government would offer things like tax amnesty for the purchase of incandescent alternatives such as florescent (assuming they aren't in bed with the energy companies and actually want energy waste--just an excuse for the energy companies to make more money lol).
Carey Pickard
1. The amount of red light produced.
(Red light is far easier on the eyes than blue light, which can actually trigger migraines in some consumers)
2. The stability of the light source in areas that experience frequent brownouts and blackouts.
(we have frequently been courted with promises of five to ten years of bulb life, only to find out that this is significantly shortened by our less than dependable electrical companies. This was not so much an issue when a bulb cost fifty cents to a dollar, but an investment of five to twenty dollars for a bulb that is even more susceptible to power variances, causes the average consumer to question the veracity of the manufacturer's grandiose claims!)
LEDs may be better, more efficient, and even more attractive, but until these questions are addressed, they will never be more popular than the inexpensive (at least to purchase) Edison model.
-Auri
-Auri
But it is also true that the remainder is transformed into heat. For places that have cooling needs most of the year, that's a double advantage: you save energy on powering your lights, and you save on cooling. But for places needing heating most of the year, the advantage is almost null. Every watt you save on lighting you are going to have so spend it on heating. And since most heating comes from sources identically as efficient as a lightbulb (the only exception being heating air conditioning, which is more efficient) then lightbulbs are a decent heating source for those places.
So it depends on where you live. If you live near the equator, go for them. If you live nearer to the poles, keep the filaments.
In the winter, when you need the heat anyway, its no biggie. But in the summer, every watt of lighting is another watt of heat that must be removed, at rates in the neighborhood of 3 watts of AC power per watt of light..
- IC bulbs are not efficient in winter either
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by k2dave
November 7, 2006 2:40 PM PST
- Yes you don't have to run the a/c to cool the extra heat they produce, but unless you have electric resistance heating you are still wasting money with IC lighting.
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Reply to this comment
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See all 60 Comments >>Gas, oil, Kero, electric heat pump, wood, or coal is MUCH CHEAPER then electric resistance heating. A IC bulb is basically a electric resistance heater, just like a portable space heater - it's a expensive way to get heat and saves you nothing, you would be far better using your home heater to provide heat efficiently and use CF lighting.