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Why LEDs Don't Beat CFLs Even Though They Should
TaeKwonDood writes "LEDs don't beat CFLs in the home yet, but it's not simply because PG&E is getting rich making people feel like they are helping the environment buying CFLs made in China that are shipped to the US using a lot more fossil fuels than they save. It's a problem of indication versus illumination. However, some new discoveries are going to change all that."
just my wallet. I got a set of LED GU10 bulbs for the flat because when we got in there were two fittings of 4x50W bulbs each, and with the energy saving from some LED replacements (~£10 for 4 at ~2W ea, normally ~£5ea but i found a deal) easily paid the difference, especially since i was having trouble finding CFL replacemetns. However they definately give off significantly less light than the 50W halogens, which is fine most of the time as i prefer a dimmer light usually, but can be a little frustrating if i find myself needing a little extra to look for something, The light is alot 'whiter' which took a couple of days to get used to but is fine now. They are also very directional, they light up one area very well, but are quite poor outside that area, so fine if you are after light in a particular area (they are often advertised as for lighting up some piece of art you want attention drawn to) but not so good if you want to illuminate a room.
an directionality. It's hard to beat CFLs and moreso some good quality fluorescent tubes get slightly more lumens per watt (although I saved 100 watts per hour in the kitchen - 200 instead of 300- by going with directed CFLs that shine line exactly where needed vs previous central flourescent tubes that were lighting from the center trying to sloppily spill light everywhere).
Since every Home Depot now takes any CFLs, the disposal is actually better than fluorescent tubes. Considering most electricity comes from coal, you prevent mercury release in the air vs incandescents. And no, you don't need a specialized clean up crew if a CFL breaks: http://www.snopes.com/medical/toxins/cfl.asp
Except for the oven, fridge, and flashing lights - CFLs are appropriate for most applications.
I would love to have LEDs. But they need to raise their efficiency. They don't generate heat as such, but AC->DC conversion does, index of refraction of the casing material presents a problem, as well that leds don't generate white light by themselves (they use phosphor?) and all that reduces the light given off.
It would be cool if those were solved one day, where they got near 90% theoretical max lumens/wax (683 lm/wt), where a 3 watt LED would give off the same light as a ~100 watt incandescent or ~23 watt CFL. Even 150 or 200 lm/wt would be a revolution. But it will take 5-10 years I suppose.
The vast majority of light bulbs are imported from China. Incandescent, halogen, fluorescent, CFL, you name it, it's likely made in China. I own a hardware store and have watched over the years as production of GE bulbs has shifted from the US to Mexico to China. It was interesting to note that some of the specialty bulbs (for example, a bulb called Lumiline) had very high defective return rates when produced in Mexico, so GE moved manufacturing back to the US for a while until the bugs were worked out.
Anyway, this transportation cost objection is bogus IMHO. Incandescents weigh slightly less than CFL's, but they take as much "cube" space in container loads so the cost to transport is probably similar to CFL's.
"We make our world significant by the courage of our questions and by the depth of our answers." Carl Sagan
>Or until government regulates incandescent out of existence.
Which many of us hope will not happen. There is no suitable replacement for incandescent in MANY applications. My house has many such.
Flor is generally not dimable. Even those that claim to be really are barely and cost a fortune.
Flor saves NO MONEY when dimmed, even if you can find expensive dimable ones.
Flor bulbs do not fit in all fixtures, especially decorative ones and small ones.
Flor bulbs are UGLY in many types of fixtures, period.
Flor FIXTURES are UGLY in many types of applications.
Flor light is not pleasing to many people- it is too white/blue or harsh.
Flor fixtures often emit lots of RFI.
Flor fixtures often emit noise.
Flor lamps are not instantly on.
Flor lamps are also not instantly 100% bright, many taking MINUTES to reach full brightness.
Until you can address all or most of those issues, there are very valid reasons to prefer incandescent lighting in many situations. I, for one, have replaced about 1/3 of all my lights with flor, but the remaining can't be because of many or all of the above reasons. If anything, tax incandescent lamps to make them cost parity with alternatives, but do not attempt to eliminate MY CHOICE until there is a truly suitable replacement.
Disclaimer: I have no experience with LED "lightbulbs" like those in TFA, only LED flashlights
To me, the biggest hangup on going to LED lighting from CFLs would be the spectral issue. In my experience, "white" LEDs don't actually put out true white light, but rather several distinct wavelengths that look approximately white to human eyes. IIRC they lose some definition with red/green. Not as big an issue for a flashlight, but in room lighting I'd kind of want all the colors showing up. This may very well be solved by now, however. I don't know.
The meek may inherit the earth, but the strong shall take the stars.
Just call them "Gucci designer LED's" or some such and stupid rich people will buy them by the thousands and the price will drop.
"I'd rather have a bottle in front of me than have to have a frontal lobotomy."
I've seen similar issues with specific outlets in my house. CFLs last about 2 months and incancesdents a year or two. The problem appears to be fluctuating power supplies. Our house's power isn't very stable... the vacuum cleaner, dryer, and other devices cause lights to slightly dim or flicker. I've solved most of it by separating the circuits, but the CFLs seem to be VERY sensitive to fluctuating electricity.
A CFL on its own circuit seems to last a long time.
E pluribus unum
I really want to switch to LEDs. I've become disillusioned with CFLs in recent years. The very first two CFLs we ever purchased, in the mid-nineties, -- my wife's reading lamp and the hard-to-reach light in the stairwell -- are still working. But in recent years (since maybe 2002) I've had a remarkable number of failures, often in the first month of use, and I rarely see more than a couple years of service. Oddly enough, I get longer service from the outside lights, which should be the harshest environment. The indoor CFL overhead lights (except for that stairwell light) last about a year. The worst service is from the CFL globe lights over the mirrors in the two bathrooms. I lose about one a month, and recently I've started replacing them with incandescents as they burn out.
I think part of this is due to putting CFLs in environments where they do not thrive -- anywhere you have heavy on/off duty cycles like a bathroom or occasionally used overhead. But I wonder also if CFLs in general haven't become (at least in part) victim to "value engineering", IE, making them as cheap as possible.
But anyway, what worries me about LEDs is that although they *should* give longer life, (50K hours vs 15K for CFL and 1K for incandescents) they apparently don't, judging by the LED array stoplights that have been put in all around the city. It's difficult to find one that doesn't have large parts of the array completely out or blinking madly. Around Christmas I noticed that some of them had been replaced with conventional bulbs. Looking at the technology, LEDs should do better, but it's all about implementation.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
I've been using CFL's since at least 1995, probably a lot earlier. Starting with the big Philips 'jam jar' types which lasted more or less forever - I still have some of the first lamps I bought, now more than 15 years old, they still work - and gradually moving to the more recent folded tube and even more recent incandescent form factor ones I have yet to see any trouble with them. They *just work*, save a *lot* of power and hardly ever burn out.
In other words, I completely fail to grasp the reluctance to change over, leading even to conspiracy theories and pseudo-science arguments against these dependable light sources. They may not be the best choice for all applications but they are a good match for most.
--frank[at]unternet.org
That is why they are great in torches, head lamps, and backlights - because you don't need complex optics to focus the light. White LEDs are still quite expensive though, so bulb made out of it would be a lot more expensive than a standard one.
The little snippet at the end of the post if off-base, but it is good to keep in mind that LEDs are significantly more environmentally friendly nonetheless. They last a long time, years and years, and they are very durable. They don't require toxic chemicals, and they are more energy efficient than CFLs.
It's actually harder than it seems. Just imagine trying to light up a room using a laser. How hard can it be, right? LEDs are *very* directional too.
It takes far more than a simple lens, or a simple reflector to manage to illuminate a workspace evenly using them. Reflectors work fine for incandescent/fluorescent and such non-directional light sources.
That's why we see LEDs thrive in many applications like flashlights and traffic lights and not others: those require directional light.
And even if you found a great way to do it, it would still add [likely significant] cost, and likely a fair amount of weight, if using optics. It would probably look like a huge catadioptric lens of a lighthouse (well, the inverse job, but a huge chunk of glass is what I meant). The best I've seen so far, is using a large number of lesser power LEDs...
The experiance of everyone I know who has tried LED light fixtures is they simply don't have the ability to decently light a room (whether this is due to thier being simply less light output or whether it is some other characteristic of the light I don't know) while CFLs do. They are also FAR more expensive than CFLs.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
The projectors my school uses seem to follow the razor business model. $20 projector, $50-70 nonstandard bulb. Unlikely that company would switch to something that lasts longer. Unless they move to a completely closed unit (no replacing the bulb/fan/power supply).
I don't preview or spellcheck.
For something more compact [...]: a diffraction grating. Add a glass frosting on top of a couple of layered diffraction gratings to make the light more evenly diffuse.
A similarly simple/cheap solution would be to use a non-perfect parabola or convex mirror. The LED beam, though directed, is not infinitely thin. Therefore, putting it at the "focal" point of a shiny, non-perfectly parabolic surface or aiming it towards a matte convex mirror would also do the trick.
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You are either buying CFLs from a completely incompetent manufacturer, or simply have a bizarre situation where reality is bending around you.
Or he's compulsive about turning off lights when he walks out of a room for two seconds. CFLs don't like to be switched many times, so they're great in a living room where you tend to turn them one once at the beginning of the evening but maybe not so much in a frequently-used bathroom.
Dewey, what part of this looks like authorities should be involved?