Long-life light-emitting diodes replace incandescent bulbs in ‘walk’ signal. (Sarah Beth Glicksteen/The Christian Science Monitor)
Will LEDs replace compact fluorescent bulbs?
EarthTalk: Light-emitting diodes hold promise, but they’re still costly and dim at the moment.
By THE EDITORS OF E MAGAZINE | October 30, 2008 edition
Q: What’s the story with LED light bulbs, reputed to be even more energy-efficient than compact fluorescents?
– Toby Eskridge, Little Rock, Ark.
A: Perhaps the ultimate “alternative to the alternative,” the LED (light-emitting diode) light bulb may well dethrone the compact fluorescent (CFL) as king of the green lighting choices. But it has a way to go yet in terms of cost and brightness.
LEDs have been used widely for decades in other applications – forming the numbers on digital clocks, lighting up watches and cellphones and, when used in clusters, illuminating traffic lights, and acting as brake and turn-signal lights on automobiles. They are used in flashlights, and form the images on large outdoor television screens.
Until recently, LED lighting has been impractical to use for most other everyday applications because it is built around costly semiconductor technology. But the price of semiconductor materials has dropped in recent years, opening the door to some exciting changes in energy-efficient, green friendly lighting options.
According to HowStuffWorks.com, LED bulbs are lit solely by the movement of electrons. Unlike incandescents, they have no filament to burn out; and unlike CFLs, they contain no mercury or other toxins.
Proponents say LEDs can last 60 times as long as incandescents and 10 times as long as CFLs. And unlike incandescents, which emit a lot of waste heat, LEDs don’t get especially hot. They are very efficient, converting a much higher percentage of electricity into light energy.
But as with early CFLs, LED bulbs are not known for their brightness. According to a January 2008 article in Science Daily, “Because of their structure and material, much of the light in standard LEDs becomes trapped, reducing the brightness of the light and making them unsuitable as the main lighting source in the home.”
LED makers get around this problem by clustering many small LED bulbs in a single casing to concentrate the light emitted. But such LED “bulbs” still don’t generate light much brighter than a 35-watt incandescent, much too little light for reading or other focused tasks.
If LEDs are going to replace incandescents and CFLs, manufacturers will have to make them brighter. EarthLED is lighting the way with its EvoLux and ZetaLux bulbs, which use multiple LEDs in a single casing to generate light. The EvoLux delivers light equal to that of a 100-watt incandescent, the company says.
But the $80 price tag per bulb is tough to swallow. The ZetaLux, which retails for $49.99, delivers light equivalent to a 50- or 60-watt incandescent bulb and will last 50,000 hours. It costs only $2 a year to run.
Other bulbmakers are working on similar designs for high-powered LED bulbs, hoping that an increase in availability will spur demand and so result in lower prices. Until then, consumers can find LED bulbs suitable for secondary and mood-lighting purposes in many hardware and big-box stores, as well as online.
Got an environmental question? Write: EarthTalk, c/o E – The Environmental Magazine, Box 5098, Westport, CT 06881. Or e-mail: earthtalk@emagazine.com.
( More stories )
Comments
2. Rob Brosa | 11.03.08
Perhaps this is a dated article but I couldn’t disagree more with LED usage. 3 years ago, LED’s were a nothing. I just returned from working in IRAQ for 6 months in areas ranging from Mosul, Diyala, and Baghdad as a field service engineer on Satellite Com equipment. I often installed or worked on SatCom equipment at night, because it was cooler in the evening, or worked in poorly lit tactical operations centers or inside Stryker vehicles. I discovered LED headlamps and flashlights were absolutely superior to any incandescent light source. I fell in love with them, not only did they appear to have much greater luminosity but a whiter, cleaner light and more focused beam (which kept me a little safer). To write LED’s off as a mood enhancer or other trivial item is a disservice to many working folks trying to light up tight places like myself. Thank you and kindest regards, Rob Brosa
3. Dan Alighieri | 11.03.08
I don’t think it’s fair to imply from the article that LEDs are not bright enough for home lighting. Using multiple LEDs in a fixture makes the fixture more than bright enough (as noted), for a price. I have installed a Cree LED Lighting Solutions ceiling light in my home entryway, which with 12 watts of power is identical in brightness and color to a 65 watt incandescent bulb. The catch is that it cost $100, which is still about two times too expensive to justify its 20-year lifetime. The LEDs are technically ready; the cost just needs to come down.
4. A. Kamran | 11.05.08
When the price comes down, I’ll be there with bells on. I have florescent lights where I can at home, but I can’t use them for reading, as they give me a headache. And since most of the places I in which spend a lot of time (office, library, etc.) are lit by florescent lights, I spend a lot of time with a headache!
5. D Bo Sky | 11.05.08
I’m a bit confused by your article’s statement, “LED bulbs are lit solely by the movement of electrons. Unlike incandescents, they have no filament to burn out; and unlike CFLs, they contain no mercury or other toxins.” Many of today’s LED’s contain gallium arsinide, commonly known as arsenic. How does this not count as an “other toxin”?
6. editorial | 11.06.08
D Bo Sky’s comment above prompted some further research on our part: Yes, the article failed to mention that gallium arsenide and aluminum gallium arsenide are used in older LEDs, and the former compound was listed as carcinogenic by the state of California in August. Some high-brightness LEDs contain arsenic compounds as well, though the “vast majority” of HB-LEDs (according to an article in LEDs Magazine, http://www.ledsmagazine.com/news/5/9/6) do not contain any gallium arsenide, but gallium nitride instead. No one has determined if gallium nitride is toxic, though no one is suggesting that you ingest it, either.
– Owen Thomas, Environment Editor
7. Mike Fitzwater | 11.07.08
Arsenide aside, my sure fire palm sized flash light is brighter by far than my six D cell mag light and has a more focused beam and whiter light while only using one LED bulb. It gets a little hot after a while on high beem but has a lower setting for longer batterie life. It is over a hundred bucks but a lot of that can be contributed to the flashlight’s construction and matirials. With technology moving as fast as it is, it is no wonder a study from almost a year ago is already outdated.
8. Uncle B | 01.28.09
In a quest for a “Zero upkeep, Zero running cost” (GRD) great republican depression shelter, LED’s draw the least current of all, and make more possible an off-grid existence. Can our eyes grow accustom to the difference in light levels and accommodate them? I know that after years of using CFL’s I find when visiting homes still using incandescents, the light is abnormally yellow and gives me “fuzzy” vision and sore eyes! Can we build a more stable economy by rejecting all but the most efficient means of independently powered living? As it is we have far too few off-grid dwellings, and in the case of disaster, or worse, the GRD, can we survive as a nation? LED’s may be one small route to winning the economic “war” we find ourselves in with a new, faster, smarter Asia!
Trackbacks/Pingbacks
1. mercury-chelation.com » Blog Archive » Will LEDs replace compact fluorescent bulbs? - Christian Science Monitor | 10.31.08
Leave a Comment
We do not publish all comments, and we do not publish comments immediately. The comments feature is a forum to discuss the ideas in our stories. Constructive debate - even pointed disagreement - is welcome, but personal attacks on other commenters are not, and will not be published.
Tip: Do not write a novel. Keep it short. We will not publish lengthy comments. Come up with your own statements. This is not a place to cut and paste an email you received. If we recognize it as such, we won't post it.
Please do not post any comments that are commercial in nature or that violate copyrights.
Finally, we will not publish any comments that we regard as obscene, defamatory, or intended to incite violence.
1. Tom Brucia | 11.03.08
This technology is moving ahead fast… I suspect it will burst upon public consciousness in two to four years, and early adopters should begin thinking now, ‘How can I benefit when LEDs begin to take over the mass market?’ I speak as someone who had a desktop computer when no one knew what one was, and was telling folks about a new-fangled communications system called ‘the internet’ (and they stared at me like I’d been drinking). Incidentally, if you go to Home Depot you’ll find LED night lights, construction lamps, etc. already in ‘the mass market’. Next, keep an eye peeled for a shift in the general lighting section over there to monitor the shift from incandescent to LEDs. (I suspect compact fluorescent lamps will always maintain their ’swing’ status in the middle, but then what do I know…)