LED Bulbs: NOT the Future of Lighting
So, some sellers on eBay are marketing these new 120v LED light bulbs (which are comprised of a cluster of dozens of individual LED's) for home use. Wow - bright light, only a couple watts, and a bulb that lasts virtually forever - what more could you want? Though expensive ($16-$25 per bulb), these sound so promising as to be the "next generation" of bulbs - surpassing even CFL's (Compact Fluorescent Light bulbs) in terms of bang for the buck.
Or so they say. We compared these fantastic-sounding new bulbs to both incandescent bulbs and CFL's in terms of light output and energy use, based on luminous intensity specifications (in lumens) of different types of bulbs from the EnergyStar.gov web site, and the LED manufacturer's light output and power consumption ratings. For example, the figures shown to the right were used to generate the graph below.
The three major problems of LED bulbs:
- More expensive. As you can see above, the LED bulb is substantially cheaper to operate than the incandescent for the same amount of light (no surprise there) but about 3x the cost to operate vs. a fluorescent;
- Odd color. The color produced by LED bulbs is not "warm" - many people describe it as "too blue." While white LEDs are becoming more natural in color temperature, they have a long way to go. CFL's are much easier to adjust to;
- So many bulbs! LED bulbs produce (depending on type) from around 35 to 105 lumens per bulb. A 60w incandescent or 13w CFL produce over 800 lumens. That's a ratio of 10:1 on average. I don't know about you, but my closets and hallways have 1 or 2 light sockets, not 10 or 20. When you consider that you'd need to use 10 LED bulbs to replace each incan or CFL, the problems are, for most of us, insurmountable! I mean, where are you going to put all those bulbs?
So, to sum it up, don't expect these bulbs to outperform CFL's in terms of initial cost, light output, or efficiency. Perhaps someday, advances in LED technology will change this. But don't place a big order for replacement bulbs for your house just yet.
LED’s take far less power than Flouro’s I am replacing all the Flouro’s in my dad’s business for a 20% reduction over “effective light” with an ROI of 10 months and savings over $14,000 over 10 years (JUST in electricity)
that little bulb you have is pathetic. it really does not work well at all for well I have not found a use for it yet.
Example I replaced my dad’s desktop with a 120led unit that is the exact same shape and size and has about 75watts of effective light and consumes only 7 watts of electricy. even a CFL can not touch that.
I light my bedroom with 4 4ft tubes that have 300led’s in each tube producing about 80-90 watts of light each (effective illumination) my room is brighter than DAYLIGHT and consumers only 44watts of power. they cost me $136 ($34 a pop shipped)
there are 2 tricks. Spread the light out (LED are very coherent like a laser. so first you need the modified lens version with a 120′ spread and you need LOTS of low power bulbs NOT a few higher power bulbs.
this removes the SPOT effect and disperses the light more evenly.
Then you need to SPACE the fixtures so the light paths cross (multiple times if possible) led can APPEAR a lot dimmer when they are unidirectional because of there coherent nature. they create a lot of shadow effect. By having multiple fixtures apread around the room you eliminate this and produce that holy grail of EVEN illumination throughout the room. as if by daylight.
Its not perfect. because of the limited structures (IE tube structures 4ft long) it limits the decors it can work in. BUT if you decor can adjust or you just don’t care about that (like me) the effect and benefit is massive.
It would take at least 2 4ft dual tube flouro’s to light my room to 75% of what I have now (I LIKE bright) thats 160watts of power consumption!!
Little CFL’s no way would take at least ??? 10 of them to fully illuminate my room. thats 110watts. (the 11watt ones are just bright enough if I spread 10 of them around) and would both look hidious and take a lot of work to install that many fixtures.
I do not know what the actual lumen output is on these things I can only voice my percieved effective output.
2 300watt halogen floor lamps (my previous favorite way to light a room) could ALMOST produce as much light as my 4 led fixtures. thats 600watts.
If all you math a data is based on that wee little pathetic led bulb then your math really is meaningless man (I am not trying to trash on you or anything just saying it how it is)
you have to use LED’s in a way that overcomes there limitations (coherent light shadowing effect) personally I LIKE colder bluer light. its more natural to me. and LED’s are available in a WARM varient (I am waiting till I can get 300led warm for my kitchen) since in THAT setting the cold lights just don’t work as well.
There not perfect but in many situations they can be SO much better than CFL’s etc..
Comment by Chris Taylor — January 31, 2007 @ 11:53 pm
I clicked on the eBay link, above, and was directed to a listed of LED bulbs available. When I chose the LED bulb mentioned here, it showed a light output of 51 lumens, not 33. Is this incorrectly marked by the seller? Does the manufacturer list different specs?
If, in fact, the seller is correct, that would make the cost per 1000 lumens = $0.39.
There is also a brighter bulb (The 5 x 1 Watt CREE LED 110 Standard Screw Base Light bulb) 300 lumens at 7W. This bulb would cost about $0.31 per 1000 lumens.
Comment by Fuzzy — February 12, 2007 @ 6:06 pm
IN RESPONSE TO THE ABOVE:
There is such a growing variety of LED bulbs with different levels of light output, at different prices, that my benchmark just shows the average as of the time the post was written.
However, I WOULD always expect the possibilty of foreign manufacturers or resellers mis-rating their products. This is a widely-practiced activity when talking about Ni-Cad or Ni-mH batteries out of China, most cheap-o, aftermarked digicam batteries on eBay are over-rated/labeled by as much as 40%. If you buy these batteries, you’d know what I mean. They just don’t compare to the original (usually Japanese-made) OEM batteries from the name brands.
This is also common of individual LED components sold on eBay, imported directly from Hong Kong or Taiwan. Their output is rated in micro-candelas (mcd) and they often overstate the specs as well. I don’t see why it wouldn’t be different for packaged LED bulbs.
Also, lumens are harder to measure with LED bulbs because they are less diffuse and more directional than incandescent or flourescent bulbs. There’s another “loophole” for the seller.
Now, with regards to the LED bulbs again, I’ll take another look at the latest: avg. nationwide cost per KwH, lumen specs from trusted manufacturers of LED bulbs, etc. and revise this post if necessary.
Thanks for the feedback; I hope this information and comparisons to the shady marketing of other products is helpful in the least.
-Brian
Comment by Brian — February 12, 2007 @ 7:29 pm
Two of the prior comments hit the problem with LED’s on the head. First it is almost a wild west in reguard to light ratings and product offerings. In time as bigger players get into the LED market, more order and uniformity will emerge. Second the dim nature of LED lighting makes them a viable replacement for only a few light bulbs in the average house/appartment. This to will improve in time. High power LED bulbs produce about twice the light for the same wattage, but unfortunatly they are mostly spot light bulbs. About the cheapest place I have found for LED light bulbs is www.shop.donsgreenstore.com . Try a couple now, or wait a couple years and there certainly will be better ones on the market.
Comment by Jeff — November 23, 2007 @ 8:57 pm