Slashdot Mirror
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."
Did you notice all the LED xmas lights this year?
You're seriously trying to claim that the savings of CFLs are offset by shipment? Really?
I would go into the obvious math or the economics, but honestly this is just simply too stupid to even deserve further comment, except that it is a completely asinine, baseless statement that I'm sure will be picked up and repeated by a lot of ignorant contrarians.
Sorry but I don't buy the optics issue. It really can't be THAT hard to put a lens or reflector in the armature and point multiple LEDs in different directions. If anything LEDs should be preferable to incandescents because it is easier to take something very directional and spread the light than it is focus the light from a divergent source. I think the main reason LEDs are not popular yet is cost and "it's not what I'm used to". Seeing the type of crap people will buy even when there are better alternatives I simply don't believe that something as sophisticated as the beam profile of an LED will be a huge issue.
But what if you had to ship 6 lights for every one due to lifespan differences?
Although I agree with some points of your post, most of your belief is not quite accurate. LEDs now make the best flash light illumination, and the power drain on batteries is minimal. I've been using LED headlamps for years, so this is nothing new, as your post implies.
The problem with them being used in homes is that they direct their illumination to a specific spot. This is not a bad thing though. I've recently seen them configured as spot lamps. Perfect for recessed lighting.
The optics in LED technology can easily be modified to diffuse light to make a great replacement for CFL & incandescent. Give it time.
"Suppose you were an idiot...and suppose you were a member of Congress...but I repeat myself." Mark Twain
Wow. Way to sneak in that lie under the radar. Politically motivated, or just simple ignorance?
In any case, no, the manufacturing and transport of CFL bulbs absolutely does not generate more CO2 than that saved by using them (assuming coal/natural gas powered, the only logical comparison in this case). Let's run some simple numbers.
Assuming an average 60-watt equivalent (12 watt nominal) CFL bulb with a lifespan of 10,000 hours, it will draw 120kWh over the course of its life. The 60-watt incandescent, if it lasted as long, would draw 600kWh. Of course, it doesn't last as long, but rather an average of 1/5 as long.
So the savings are roughly 480kWh for an 800lm fixture. That's the equivalent of over 400 liters of gasoline burned in an internal combustion engine, and that doesn't include the fuel used building, shipping and shopping for replacement incandencents, which as mentioned burn out far more frequently.
Now for some logic. How is it that a bulb which apparently requires >480kWh of energy to build/ship ($48 at $0.10/kWh) sells for a few dollars? Hint: it doesn't require >480kWh of energy to build/ship, or anywhere near that.
CFLs offer a massive net efficiency gain, and by extension, a net reduction in CO2 emissions. Even factoring in disposal costs at 5 times the manufacturing cost (silly), CFLs are a net win. So please don't spread that tripe!
A government is a body of people notably ungoverned - AC
If a 25W CFL replaces a 100W incandescent bulb, and the CFL lasts 8000 hours, it will save 600 KWHrs of energy. .11 gallons of diesel for the journey. That is about 6 KWHrs of energy.
If a shipping vessel can hold 35,000 tons of cargo and the shipping weight of a CFL is 1/2 pound, the vessel can hold 140 million bulbs. Of course there is not enough space for them all, but they can ship with heavier items, and I am assuming costs are allocated by weight.
If a 7,000 mile journey burns 875 tons of fuel, or 15.75 million gallons, then each bulb is allocated
Therefore, the shipping costs don't even come close to negating the energy savings.
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
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.
You are either buying CFLs from a completely incompetent manufacturer, or simply have a bizarre situation where reality is bending around you.
I replaced all bulbs in my home with CFLs three years ago. None have burned out to date, and I saw a small but measureable decrease in home energy use, as my home energy costs are very stable. Everyone I know who has replaced all or some of their bulbs have had the same experience.
There's demonstrable energy savings to be had, and a measureable lifespan increase simply due to the physics of CFL versus incandescent.
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.
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...
Just call them "iLED's" or some such and stupid rich people will buy them by the thousands and the price will drop.
Fixed that for you.
Linux, you magnificent bastard, I read the fucking manual!
Have you done it recently? The CFLs I bought in the nineties are still working. The ones I bought last year aren't measurably any longer lasting than the few incandescents I still use. I suspect that now everyone has jumped on the bandwagon, there are a lot of crappy cut-rate CFLs being made. And I'm pretty sure that this isn't being taken into account in figuring overall real-world environmental impact.
Contributing to this, as Fred and Ethyl Mertz buy eight-packs of CFLs at Costco, they're certainly using them in situations where they don't work well -- like areas where the lights go on and off frequently. (I made this mistake initially -- couldn't figure out why CFLs were lasting months rather than years in the bathroom.) Which, as you point out, really is doing it wrong. CFLs work well in narrowly-defined environments -- they're not a replacement for every bulb in the house. The general public doesn't appear to realize this, and the retailers are in no hurry to correct their misunderstanding.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
A glass of cloudy water would do what you ask, quite easily.
Space Shuttle was a program that strapped humans to an explosion and tried to stab through the sky with fire and math
No, it's valid if they're both made extra-nationally, but in different places. Most incandescents are actually made in the United States by GE, but the vast bulk of the remainder are made in Mexico, and shipped up by rail, which is far more efficient than slow-boating them from China. It turns out that there are more than one country outside of America, and that those countries aren't actually all in the same location.
Of course, if anyone actually did the math, they'd find out that the energy cost of shipping is offset by the energy savings in usage in under three days; sometimes I wonder whether people have any idea how many lightbulbs fit on a large boat, or how little fuel a large boat actually needs.
But hey, made up math is great for making arguments, right?
StoneCypher is Full of BS
Without even doing any calculations of the amount of fuel needed to ship the CFL, it's obvious that this environmental cost is more than offset by the savings in power of using a CFL vs an incandescent. The simple way to figure this out is to look at the price, and the cost savings of the bulb over a couple months time. A new CFL only costs a couple dollars to buy. That means (unless companies are selling them at a loss) that it costs less than this amount to ship the bulb to you. Assuming for a minute that the cost of energy in fuel and coal powering a power plant are the same (with the same efficiencies etc, in reality the power grid powered by coal is generally cheaper per watt, but that's okay), if you can make up the cost of the bulb in a matter of months by lowering your electric bill, you have more than made up for the cost of shipping.
I always laugh when people start talking about carbon footprints and all that. Currently the simplest and only real way to drastically reduce your carbon footprint is to spend less money. Things that cost more in general have a greater carbon footprint (there are exceptions to this rule, but it often holds true). So the footprint of manufacturing a new stove is roughly proportional to how much the stove costs (obviously if you're buying a gold plated stove with platinum racks this won't quite hold true). So the quickest way to halve the US's carbon footprint is to cut the US's spending power in half. Of course, with the steps the government is taking to reverse the current economic crisis, they could easily accomplish this.
Phil
That article repeats a bunch of CFL myths. I find it amazing to watch some in the geek crowd glob onto any "science" related conspiracy ("global warming is fake", "the Hindenburg didn't burn from hydrogen", etc) the same way tin-foil hat people glob onto the "moon hoax" or "there was no plane crash at the Pentagon on 9/11".
We even were treated to one in the header of this article:
"CFLs made in China that are shipped to the US using a lot more fossil fuels than they save."
Oh, really, is that so? Shipping cargo takes about one gallon of gas per ton of cargo per 500 miles. Shanghai is ~6500 miles from LA. Thus, 154 pounds can cross the Pacific per gallon of diesel. A gallon of diesel contains 130MJ. A CFL weighs perhaps a quarter pound. Therefore, it takes 211kJ of fuel energy per bulb. If we assume the big diesel engine is roughly as efficient as a power plant's electricity generation, we can compare them directly. 211 kilojoules is 0.05 kilowatt hours. If usage that bulb reduces 60 watts down to 15, thus saving 45 watts, it'd take barely over an hour to pay off the energy used in shipping it.
Of course, you also need to include train shipping energy consumption to get it to and from the ports, which is more like one gallon per ton per 300 miles, but that too is trivial to pay off.
Anchor: "We take you now to our Chief Meteorologist, Paris Hilton." Paris: "It's hot." Anchor: "Thank you."