Lifecycle Energy Costs of LED, CFL Bulbs Calculated

necro81 writes "The NY Times is reporting on a new study from Osram, a German lighting manufacturer, which has calculated the total lifecycle energy costs of three lightbulb technologies and found that both LEDs and CFLs use approximately 20% of the energy of incandescents over their lifetimes. While it is well known that the newer lighting technologies use a fraction of the energy of incandescents to produce the same amount of light, it has not been proven whether higher manufacturing energy costs kept the new lighting from offering a net gain. The study found that the manufacturing and distribution energy costs of all lightbulb technologies are only about 2% of their total lifetime energy cost — a tiny fraction of the energy used to produce light." The study uses the assumption that LEDs last 2.5 times longer than CFLs, and 25 times longer than incandescents.

Comments

Great assumption

[CrazyJim1]

Assuming LEDs last 2.5 times as long as LEDs, we conclude that LEDs last infinitely long and there is nothing superior except for LEDs.

Re:Great assumption

[ihuntrocks]

That divide by zero could mean undefined and could be infinity. This leads me to the startling conclusion that LEDs don't actually produce light, but actually consume darkness. There is a strange event-horizon inside of LEDs that prevents us from observing what's going on inside. On the inside, I postulate that the mechanism inside of the LEDs let's virtual pairs of "no-tons" and "anti-no-tons" form, orbit, collide, and destroy one another. This releases the occasional photon. There is virtually no heat from this, since no-tons, by nature, are incredibly low energy particles. This must happen at a tremendous rate for the "light output" they give. I am both amazed and slightly afraid of LEDs now that I know how they work. I only hope the manufacturers continue using this awesome ability for good. ...Silly article typos....

Re:Great assumption

[amorsen]

Start with outdoor lighting. Outdoor lights, by their very nature, must be sealed. CFLs contain lots of electronic components, including electrolytic capacitors. In a sealed enclosure, these parts can heat up beyond the thermal limits of their components within minutes. Therefore, for outdoor use, you should not use CFLs, period.

Don't be ridiculous. Most street lights aren't incandescents. Most streets are outdoor.

I'm pretty fed up with the same tired B.S. arguments being trotted out by manufacturers to try to convince people to buy CFLs and LED lights.

I think it's clear where the B.S. is.

Re:Great assumption

[Alioth]

[citation needed]

Sorry, it sounds like you're just resistant to change.

On the subject of outdoor lighting, I started using CFLs in outdoor lights 15 years ago, precisely because the incandescent ones lasted so little time (requiring a ladder to replace, and the associated falling-off-a-ladder risk). At that time, it was the only place I was using CFLs. Even then, they lasted several times longer than incandescent bulbs and used a lot less energy - they had no trouble getting their rated lifetime. At that point we lived in a part of a country that regularly falls well below freezing during the winter. Cold was never a problem. The very same heat you say will break the lamp soon gets the tube warm.

LEDs are expected to become more energy efficient than CFL, so the heat "problem" (which I've never observed) would be even less. LEDs would be absolutely perfect in refrigerators - less heat emitted into the refrigerator which means less work to do for the refrigeration machinery. Since I have built my own LED lighting units from components, I can tell you that (a) they don't have many and (b) no electrolytic capacitors either, and (c) the temperature never gets near exceeding the rated maximum on any of the components at least for 3W Lumiled cool white Luxeon Rebels. The circuit consists of a current regulating power supply (purpose made for LED lighting) - basically a small 5 pin IC, some ceramic chip capacitors, a sense resistor, an inductor, and a schottky diode. Electrolytic capacitors are inappropriate for this small switch mode power supply, their ESR is too high. The power supply circuit for two 3W Rebels is about the size of a postage stamp even on a home-etched PCB. With a factory made PCB you could probably make it half the size without much difficulty.

LEDs are very commonly used for bicycle headlamps, they have almost totally displaced filament lights. I have a 3W LED front light for my bike. It is a sealed, self contained unit complete with battery, about 50% larger than a D-cell battery in each dimension, and will last over an hour off a charge at full brightness. No overheating problems.

The dimming of CFLs as they get old and fail is a much more graceful failure mode than sudden complete failure by an incandescent. It gives you more warning the lamp needs replacing, and doesn't leave you grovelling in the dark trying to replace a bulb when it fails just when it's inconvenient.

Re:Great assumption

[LanMan04]

Indeed. Most street lights are sodium vapor (sometimes mercury) vapor: http://en.wikipedia.org/wiki/Sodium_vapor_lamp

Another things to consider

[Sycraft-fu]

Is heat output. More or less, any energy that isn't becoming light is becoming heat. Now in some areas of the world, that matters little to none. However in hot climates, it does. An incandescent produces more heat which gets dumped in to the air in your house. You then have to run your AC more often. So you end up paying double for the power, in terms of using it and then eliminating the excess. That's one reason I rather like CFLs is that they heat up my place less. I live in the desert so that is a non-trivial thing.

Also, they can have a much more natural white point. I like the fact that you can get CFLs with a white around 6000, which is closer to what you get from the sun on a bright day. Just a much nicer quality of light. You do generally need to pay more to get higher quality ones with a better spectrum, but I'd say it is worth it.

Re:Another things to consider

[hedgemage]

I am practically a professional light-bulb changer, so I will say that in my non-scientific, non-measured, purely anecdotal experience, that CFLs put out a lot more heat than LEDs. Scads less than incandescents, but still, the ballast in the base of a CFL warms up quite a bit during operation, often growing too hot to touch when the glass spiral is still plenty cool. If you're concerned about minimizing heat, go LED.

Re:Another things to consider

[jackchance]

I absolutely agree. In winter, instead of turning on your heat, you should just run your computer doing folding@home or whatever to try to put out enough heat to keep your place at a comfy temp. It's crazy to just put the electricity through a resistor when you could be getting CPU cycles out of it!!!

Eh

[ShooterNeo]

Incandescent bulbs :
+ Cheap, we're used to the light
- terrible efficiency, short lifespan, fragile, sensitive to vibration, emit heat

CFLs :
+ much more efficient, very long lifespan
- not very dimmable, contain mercury, fragile, slow to start up in cold environs, reduced lifespan if toggled on and off

LEDs
+ extremely efficient, ridiculous lifespan (60,000 hours), almost bulletproof, can toggle on and off as much as you want, start up instantly in all environs, dimmable, no toxic materials. Basically almost perfect in every way.
- $$$$$$$$$$$$$$$$. Current generation light spectra is too high a color temperature to mimic incandescents. Current generation packaging creates a narrow, focused cone of light.

Summary : LED will pwn all once the problems are solved, and the problems appear solvable. Problems with other light technologies are inherent to the technology itself and not solvable. Once LED is perfected, the other two technologies will be useless.
 

Re:Eh

[ShooterNeo]

Read what I wrote : problems with current packaging. The reason they do that NOW is that LEDs are so expensive that it's not possible to put enough of them into a light bulb to match the total lumen output of a conventional bulb. So to make use of the limited light output, they leave the light focused in those narrow cones. Once LEDs get cheaper, they'll come packed with diverging lenses or diffusers to spread the light around.

Re:Eh

[tftp]

LEDs [...] no toxic materials

Gallium arsenide is a carcinogen, and arsenic is released when the crystal is exposed to water (after the LED light is thrown out and ends up in a landfill.) Manufacturing of semiconductors is producing poisonous waste, and it requires large amounts of energy.

Currently a 1W desk lamp (of which I happen to have two) uses about 30 LEDs. It is cool to the touch, but the light is mostly blue, and the intensity of the light is just enough to use it as a night light. I like these lamps for what I'm using them, but there is no way currently to replace the overhead lights with them, they are 100x too weak and 10x too expensive.

Bu.. bu.. but...

[timeOday]

Since this is an energy-saving technology, surely it has some fatal yet under-appreciated drawback that fully justifies my foregone decision never to change my habits or lifestyle for any reason and makes fools of the "greenies" in my own mind! You know, like how Hummers are actually more eco-friendly than the Prius, and how windmills screw with feng shui. I've always found an excuse to view all environmentalism as self-defeating before, don't let me down this time slashdot!

Easy Bake Ovens

[Dan East]

Doesn't anyone ever think of the children? What about Easy Bake Ovens? Have you ever tried to bake a tiny little cake from the heat emitted by LED bulb? No adult, let alone child, has that sort of patience.

Re:No shit, sherlock.

[timeOday]

A CFL costs maybe $5 each (if you buy a pack with more than one)

Actually brand-name CFL's delivered to your door are a little over $1 each.

Re:LED lighting vs. CFL question

[HornWumpus]

Because with LEDs you only make the part of the spectrum that the tomatoes growing in the closet use.

Seriously it's the longer life.

Especially the increased on/off cycles, which is what kills almost all CFLs before their time.

Re:No shit, sherlock.

[ThreeGigs]

in an objective, blind test

Personally, I'd never trust a lightbulb test done by the blind.

Professional light-bulb changer?

[SteveFoerster]

I am practically a professional light-bulb changer

So, how many of you does it take to... oh, never mind.

Pimping LEDs

[Doc Ruby]

That study as reported in the details didn't show significant difference between overall LED and CFL efficiencies. But the article consistently pushed LEDs. The headline mentioned only LEDs; LEDs were mentioned every time continuing advances were touted, the mercury in CFLs were pointed out (but not the toxic byproducts unique to LED production). The article's picture shows LEDs, not CFLs.

Yet LEDs don't really compete with CFLs yet. The article does mention that even a 60W incandescent equivalent is just experimental in LEDs, though CFLs have brightnesses at all levels even far past equivalence to 100W incandescents. Meanwhile, LEDs still generally aren't as efficient as their equivalent brightness CFLs. And LEDs' extra inefficiency puts heat into rooms that then require extra cooling, which consumes more energy.

LEDs are probably going to outperform CFLs. Their colors will be better than CFLs, their efficiencies probably better than double CFLs. They're smaller, probably able to be less toxic to produce and discard. Their DC power offers better efficiency direct from solar power (or its battery storage) than AC CFLs can get. But not yet. This article makes LEDs seem better than CFLs, but they're not now. It's marketing disguised as reporting. Probably the lack of numbers in an article about engineering performance should be the tipoff.

Re:No shit, sherlock.

[Inda]

I feel like a parrot because I post this so often:

If you live in the UK don't buy CFLs. Phone your energy supplier and ask them how you can save electric. Mention you like the look of CFLs. They will send you a box for nothing. They will also send you one of these new-fangled LCD energy meters, if you ask. They just sent me enough roof insulation to cover the whole roof space, 270mm thick, for sixteen quid.

They have to do this. It is the law. A certain amount of profit has to be given away for energy saving measures. Everyone qualifies, not just new customers.

Yes, I work in the industry.