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

[Rising Ape]

Or they never work at all.

Re:Great assumption

[startled]

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.

The study was commissioned by an LED manufacturer. In order to reach the desired result, they had to redefine 2.5 as the multiplicative identity. At least they're up front about it. ("Up front" being, in fact, quite important-- you don't want to see what they did to the associative property.)

Re:Great assumption

[Inner_Child]

ME TOO!

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

[Pieroxy]

To be honest, after having spent more than $400 in LED bulbs (that's not many bulbs trust me), most of them have died after a year or so. I'm talking about the bulbs, not the LEDs of course. I have no doubt they still have 25000 hours in stock, buit without the electronic to light them, it's very little use.

My blog on the subject (in french...)

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

[SenseiLeNoir]

We have used a CFL (not the spiral type, but the stright type, philips) for our outdoor light for the last two years. Its still going strong, and we live in unpredictable London (hot-ish in summer, fscking cold in winter)

Re:Great assumption

[Muad'Dave]

LED lamps will almost certainly have the same thermal failure problems for precisely the same reason. Electronic circuits are simply not designed to operate at such high temperatures, and when you try to use them that way, they will fail much, much sooner than they ordinarily would.

Not to burst your bubble, but you know that LEDs are made from silicon and other semiconductors jut like MOSFETS and CPU's, right? They run at _very_ high temperatures - the max junction temperature of many MOSFETS can run as high as 175-200C!

This figure shows a Vfwd vs temp graph of an LED junction temp of 120C.

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

Re:Great assumption

[Albanach]

At the moment my incandescent light bulbs are 100% efficient.

Are you aware that heat rises? Do you spend a lot of time sitting on your ceiling?

It's all very well to make heat, but it's pointless to be making it where it's not needed. That's not in any way efficient.

Re:Great assumption

[sgtrock]

But by far, the biggest problem with these studies is that they universally fail to take into account all the places where neither CFL nor LED bulbs can be used at all. 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.

As others have already pointed out, this is total nonsense. The first place that I started using CFLs was to replace the incandescent outdoor floods on my garage and house. I had grown tired of climbing a ladder to replace lightbulbs every several months. I haven't had to replace a single CFL since I installed the first one.

BTW, I live in Minnesota, a state known for its extreme temperature swings. Since I replaced those bulbs several years ago, the temps here have ranged from a lows of about 40 below to recorded highs of 95+ above zero (Fahrenheit).

Re:Great assumption

[johno.ie]

This is why I'm always horrified by stores selling clothing under fluorescent light.

Hrrmmm, yes that is truly horrific behaviour. We should call in the army to deal with those retail outlets that cause so much distress to innocent consumers. Think of the consumers.

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.

Bovine Excrement. Outdoor lights should be weatherproof, that is not the same thing as hermetically sealed. Just off the top of my head, I can think of at least 6 outdoors lights that are using CFLs for the last few years. CFLs do not produce a lot of heat, perhaps 10% of the total wattage of the bulb. Even for very bright CFLs, that's about 3W of heat. A metal light enclosure will conduct heat away from the bulb so fast that you won't be able to measure a temperature difference between the inside and outside of the enclosure. Even a plastic enclosure will not trap enough heat to cause a temperature difference of more than a couple of degrees.

LED lamps will almost certainly have the same thermal failure problems for precisely the same reason.

Sorry, but precisely the same reason is actually no reason at all. LEDs use a tiny amount of power, ergo there is very little heat produced. Now I will admit that if you put a CFL, an LED and an incandescent bulb in the same sealed and insulated enclosure and turned them all on that the CFL and LED might well fail before the incandescent. That's because the heat from the incandescent will fry the other 2. But what kinda idiot would design an experiment like that?

Re:Great assumption

[jeffmeden]

Electric heat? In the US at least, natural gas costs about 1/3 of what electricity does per rendered BTU. Many homes have natural gas heating for this purpose, and deriving heat from electricity could be seen as only contributing 1/3 cost efficiency when considered to be a heat source. Not to mention summer cooling costs; are you suggesting swapping out incandescents for CFLs during the summer months? Interesting theory, I look forward to some math on the subject.

Re:Great assumption

[grgyle]

I am a lighting engineer...

LED lamps are used all the time in aviation, where they are certified for high humidity, immersion, salt spray, and temperature extremes. It is commonplace to seal them and use conductive heat sinks to dissipate the internal heat. Thermal failure problems are well understood and well mitigated.

CFL fixtures can also be easily protected. It is all about using the right lamp type for the right job, no one is claiming that a CFL is the best for commercial street lighting, for example, where sodium lamps offer superior benefits, and especially not in an oven!

With regards to color vs energy, CFLs and white LEDs use a phoshpor to reradiate a broader color spectrum. The efficacy losses due to light outside of your visual spectrum are a very small fraction of the total output. While your comments with regard to color quality vs aesthetics are important, you assumptions about color vs efficacy are more or less false.

And one more aside, I'm even using standard spiral CFLs in my outdoor porch and carport now exposed to rain and weather, with no problems. They've lasted over 2 years now.

Re:Great assumption

[James McP]

Oh please. First off, incandescents come in different color spectrums just like CFLs so just because the bulb is incadescent doesn't mean it's "good" light. Second, most of your time spent indoors is under flourescent light (work, restaurants, movie theaters) ergo shopping for work and night-time clothing is best done under flourescents.

You can get CFLs with a Power Factor of 90% or higher, so I call shenanagins. The capacative load increase of a CFL is completely negligible compared to the reduced active power consumption. I point to the fact my power utility is giving away CFLs by the dozen as evidence that power generation/distribution engineers find CFLs to be effective.

I have many CFLs in outdoor applications. I have a barn with 8 bulbs. The first year I put up 6 incandescents and 2 CFLs. My wife was afraid the CFLs wouldn't start up quickly enough so I put up 2 as a test.

In the first year 5 of the 6 incandescents died between our 100F summers and 20F winters. I replaced those 5 with CFLs that have continued to work for the last 2 years. Once my wife decided the CFLs provided good light in winter, I replaced that last incandescent.

Given that 3 of the bulbs are located 25ft off the ground, I really appreciate not having to change the bulbs annually.

I also replaced our two porch spotlights with outdoor CFLs. Yeah, they don't come up to full power immediately in cold weather but I upsized the bulbs. I went from 75W incandescents (950lumens) to 23W (1300 lumen) CFLs so I still have a hefty power savings and they start out almost as bright as the incandescents.

Re:Great assumption

[mea37]

What a load of mindless FUD.

Color of light can cause differences in how light is perceived, particularly if you buy old/cheap CFL's. This used to be a major issue to me. Now I use CFL's in most of my house, and in most places there is no perceivable difference; in part because the newer bulbs are more natural, and in part because different is not the same as inferior.

You refer to incandescants as "full-spectrum"; this is misleading, as if there were one magically "correct" color that light should be. In fact, there are many types of incandescant with different light characteristics, just as there are with modern CFL.

I don't know what your comment about buying clothes has to do with anything. Large stores have had consumers shopping under flourescant light for decades. A small shop with incandescant lights is an exception, not the rule. Store light quality is typically at least as poor as even the cheap CFL's, and until recently they had the added "bonus" of perceivable flicker.

You talk about how "likely" you think it is that the dimming of bulbs befoer failure would change the equation, but you offer no numbers at all. None of the CFL's I've used has dimmed yet, and they've already lasted much longer than an incandescant. Long enough to save me money over the bulb's lifetime, and that's a key point. TFA claims it was previously unknown whether CFL's had lower lifecycle energy costs, but that's only true if you either (1) have not compared the lifecycle costs to the consumer, or (2) assume (incorrectly) that someone is subsidizing the up-front energy costs of CFL's.

You meantion negative health effects; citation needed.

You mention power factor, but you're clearly counting on your readers not knowing what that means. It's also clear from how you used it that you don't know what it means. (A power factor of .5 does not mean that the grid delivers twice as much energy, as you imply. If you think it does, please feel free to explain where that extra energy goes. You have heard of thermodynamics, right? That said, there would be a slight loss of system efficiency due to power factor, if not for the fact that power companies can and do balance the power factor out as it otherwise would cost them money.)

As for where you can't use CFL's:

Start with outdoor lights. I use CFL's in several. Some are even in my garage rafters, where they get hotter than if they were truly outside. They've all survived a St. Louis summer; not one has overheated. They've also survivied a St. Louis winter; I still got light out of them.

Even if all of the special-purpose applications where you claim CFL's won't work, were really applications where CFL's won't work, that would accuont for a tiny fraction of the lighting needs of the average consumer; if that's "by far, the biggest problem" you can come up with, then you're basically admitting there's no significant problem to speak of.

Re:Great assumption

[ryanov]

I have looked at it for CFL's (might have been Philipps, but I'm not sure). The deal there was that the shipping and handling cost of a warranty replacement was more than the bulb. With more expensive LED's, that may not be true, but I was pretty ticked off when I found that out (I had one fail in a few weeks that was clearly defective in some way).

Re:Great assumption

[ChrisMaple]

The cheapest LED lights that run from 120V are nightlights. The circuit consists of a capacitor to control current by I=C*dV/dt, a resistor to limit current when voltage spikes, a rectifier bridge so that the LED glows on both half cycles, and the LED. Sometimes there's an additional capacitor added for some reason. Any current draw variation caused by LED tempco is too small to be meaningful. No transistors of any type needed.

Re:Great assumption

[fractoid]

Sorry, but precisely the same reason is actually no reason at all. LEDs use a tiny amount of power, ergo there is very little heat produced. Now I will admit that if you put a CFL, an LED and an incandescent bulb in the same sealed and insulated enclosure and turned them all on that the CFL and LED might well fail before the incandescent. That's because the heat from the incandescent will fry the other 2. But what kinda idiot would design an experiment like that?

LEDs produce a lot less heat than incandescent lights for a given brightness, but they're really not efficient in terms of turning electrical energy into light energy. The best figures I can find are around 12% efficient (for as-yet-unreleased LED lighting giving 80 lumens per watt of input energy, and using the best-possible-case conversion of 680 lumens ~= 1 watt of radiant energy.

Re:Great assumption

[Jeprey]

> Not to burst your bubble, but you know that LEDs are made from silicon and other semiconductors
> jut like MOSFETS and CPU's, right? They run at _very_ high temperatures - the max junction temperature
> of many MOSFETS can run as high as 175-200C!

LOL. Classic example of "fractal wrongness".

I work in semiconductor device physics and device reliability for a living. I've been involved in the design analog circuits and ICs professionally for 30+ years.

1. Silicon devices can not operate at high temperatures and still work for long. 200C is the standard temperature we use to accelerate silicon devices to rapid failure for the purposes of determining room temperature failure times. Typical failure in such testing occurs within seconds to hours at 200C depending on the electrical bias used.
2. No LED is made from silicon. All LEDs are and always have been III-V compound semiconductor devices. wLEDs are all of the minimal geometry heterojunction variety - they are really LEDs that produce blue, indigo, violet or UV light which stimulates a phosphor either on the LED device itself or in the plastic encapsulate to produce white light through simple fluorescence (exactly the same as a CFL or ballast-fired fluorescent bubble but lower power).
3. III-V semiconductor devices are far more sensitive to heat than silicon devices. This is due to the higher mobilities combined with the tendency toward positive temperature coefficients in many. These make them more sensitive because current increases with temperature and can even have a positive feedback loop that makes them inherently unstable thermally (worst case they burn out and burn out far too quickly). It's not unusual for a laser diode (a III-V device) to have 3 terminals: one "ground", one for power bias, and one for temperature monitoring output to attempt to control the thermal runaway that tends to occur for the above reasons.
4. Temperature, voltage and current accelerate failure mechanisms in all semiconductors. In the case of III-V, the temperature sensitivity issue radically enhances the life time degradation (III-V fails quicker at the same temperature and geometry than silicon in most cases). This is due to the above thermal reasons but also because heterojunctions are far smaller and more sensitive to damage than the homojunctions used in silicon. The smaller you make anything, the shorter the life time it will have - defects have more impact when you reduce the number of atoms in the device - a very concerning feature of nanoelectronics.
5. I would never recommend any commercially sold product use just resistor biasing, for example, in a wLED product for the above failure risk. There's a story floating around about SCEdison fielding wLED street lights and having 60% failure in 6 months. I wouldn't be surprised if it were true - I'd bet resistor bias was used in said wLED modules. You are opening your company up for massive lawsuits if not failure. This is why companies like National Semi, Linear Technologies, Texas Instruments and Analog Devices all have "Switching Power Supply LED Bias ICs" - it's the only way to reliably operate any LED circuit under high power for long life. The only way.
6. The diagram of junction voltage vs. junction temperatures only show what the junction voltage is to achieve a given current or light output with temperature. It says absolutely nothing about whether you should ever operate at those junction temperatures. The short answer is you never should do so. Considering ambient temperature effects on heat dissipation combined with life time degradation due to temperature acceleration, prudent engineering design would keep the junction temperature well below 40C-50C for maximum life time. Since very little empirical data exists for wLED device reliability, a conservative design would be best. Anything else and you are lying (deluding yourself) about your products longevity with your customers. That tends

LED lighting vs. CFL question

[Anonymous Coward]

Does anyone know if LED lighting can save on power over CFL with the same output (lumens)?

I purchased some LED bulbs and they tend to be much more expensive and the savings (watt rating) is very negligible. What makes LED more attractive? Is it just the longer life time?
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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:LED lighting vs. CFL question

[gabebear]

Probably the single best thing about the current LED bulbs is you can throw them away. All florescent bulbs(CFLs included) contain mercury. Also, CFLs that operate in freezing conditions are very expensive and still don't work that well. LEDs can also be dimmed easily and come in any color you want, or even every color.

LED technology is still progressing rapidly, so hopefully we will see LED bulbs that trounce CFL efficiency pretty soon.

Re:LED lighting vs. CFL question

[Firehed]

1) You won't need a hazmat team to clean up when one breaks

Can we stop with this already? Unless you start licking the floor where you dropped the bulb, it's not a problem. And if you DO start licking the floor when dropping a bulb, you deserve whatever happens to you (which, in all likelihood, is just going to be a lot of glass shards in your tongue)

Re:LED lighting vs. CFL question

[Galactic Dominator]

Can we stop with dumbasses giving health advice?

http://en.wikipedia.org/wiki/Compact_fluorescent_lamp#Broken_and_discarded_lamps

Re:LED lighting vs. CFL question

[innocent_white_lamb]

CFLs that operate in freezing conditions are very expensive and still don't work that well.
 
People keep saying this.
 
I live where it gets below -40 in the winter and I use ordinary CFL bulbs in my outside security lights that stay on all night. In the coldest days of winter, they still work fine. They take about 15 minutes to warm up when it's really cold (they come on almost instantly in the summer) and during that 15 minutes they give off a weak pinkish glow. But after they get warmed up, they're fine for the rest of the night.
 
I couldn't use them in my unheated garage, of course, because I want to be able to switch that light on, do my thing, and switch it off again. But in an application where the lights stay on all night, regular CFL bulbs work fine in the coldest days of winter.

Re:LED lighting vs. CFL question

[Toonol]

Good, because CFL bulbs have been a major disappointment for me. In practice, the 10x longer lifespan compared to ordinary light bulbs turned out to be a lie. In my home they've lasted about equally long as ordinary light bulbs. They also weren't as bright as advertised; a bulb that was advertised as being as bright as a 100W incandescent bulb actually looks remarkably less bright.

That has been my experience as well.

I will probably buy $100 worth of incandescents and store them in my attic, once they start rattling their sabres about banning them in my state. I don't MIND CFLs, but they aren't yet up to the quality of incandescents... and their other virtues aren't great enough to make up for the lacking quality of light. I sometimes work on art; CFLs just don't cut it. Anything with severe spectrum peaks fouls up colors.

Re:LED lighting vs. CFL question

[ArsenneLupin]

Indeed. You get more mercury by sharing an office where somebody eats tunafish, than by breaking a CFL. Passive tuna eating should not be taken lightly!

Re:LED lighting vs. CFL question

[bestalexguy]

What about babies touching the floor and licking their fingers? Do they deserve their fate, too? Which is the right punishment for a toddler whose mother is not an expert in removing poisoning substances from contaminated surfaces? What is unreasonable in trying to keep as many hazardous materials as possible outside the household?

Re:LED lighting vs. CFL question

[Orne]

First generation CFLs contained a level of mercury that today would be considered excessive (25-50 mg / bulb), and the broken bulbs of early adopters are what spawned the big "EPA cleanup" panic with CFLs a couple of years ago. Since 2007, the mercury level in today's generation of CFLs (3mg) is "mostly harmless", i.e. broom-sweepable.

Individual Fluorescent Bulbs - About 60 percent of all fluorescent lamps sold in the U.S. in 2004 contained 10 mg of mercury or less. The remaining 40 percent contained more than 10 mg and up to 100 mg of mercury. Four-foot linear fluorescent lamps contained an average of 13.3 mg, with a high of 70 mg and a low of 2.5 mg. Compact fluorescents (CFLs) had the least amount of mercury per lamp in 2004; two-thirds of CFLs contained 5 mg of mercury or less, while 96 percent contained 10 mg or less. --Consumer and Commercial Products | Mercury | US EPA

Oh for fucks sake

[ArchieBunker]

How can these "editors" screw up a single sentence? They're not even janitors.

Re:Oh for fucks sake

[TapeCutter]

"So how many DOES it take to screw in a light bulb anyway?"

I'd say about 10, one to do it the first time and the other 9 for the dupes.

Summary fail

[jaxtherat]

"LEDs last 2.5 times as long as LEDs"

yeah...

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

[texas neuron]

Actually - you have it backwards. Let's say the SEER rating of your air conditioner is 12. This means you move 12 BTU(thermal) for every 1 watt-hours of electric energy used. The energy equivalent of 1 BTU(thermal) is .29 watt-hours. You therefore move 12 x 0.29 watt hours (thermal) for every watt-hour (electric) or 3.48.

Re:Another things to consider

[whoever57]

The heat issue goes both ways, too. Portland, OR recently started using LEDs in all of the street lamps, slowly fazing them in as the old incandescent bulbs fail and need to be replaced

I doubt they use incandescent bulbs. High-pressure discharge lamps such as mercury vapor or metal halide bulbs perhaps. These are far more efficient that incandescent bulbs, although not as efficient as LEDs. If they have a yellow color, they will be low-pressure sodium or high-pressure sodium.

Re:Another things to consider

[Rakshasa Taisab]

Wait... What?

Are you claiming that heat output only matters in warm climates? If you've ever been living in one of the northern countries you know that except for two months or so of the year, any extra heat sources in the home is a _good_ thing. Heat production is not wasted energy.

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!!!

No shit, sherlock.

[Timothy Brownawell]

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 been unproven 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.

A CFL costs maybe $5 each (if you buy a pack with more than one), including the retail markup, and saves maybe $40/year in electricity for supposedly 7+ years. I know manufacturers probably get their energy a bit cheaper than home electric rates, but it can't possibly be the 56+ times cheaper that it would take for the $5 to cover more energy than the $40*7 saved does.

Re:No shit, sherlock.

[ShooterNeo]

I bought n-vision CFLs, which scored the highest in an objective, blind test done by popular mechanics a couple years ago. They were about $2 each with shipping, and have a 9 year warranty. So far, they've lived up to their promise : the light is almost EXACTLY like the light from an incandescent - low color temperature, lots of yellow, etc. They start up instantly, and of course use a fraction of the electricity.

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:No shit, sherlock.

[ThreeGigs]

in an objective, blind test

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

Re:No shit, sherlock.

[amRadioHed]

Depends on how you were going to get yourself to the store otherwise.

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.

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.

Re:Eh

[hitmark]

these days, i wonder whats not a carcinogen...

Re:Eh

[Timothy Brownawell]

these days, i wonder whats not a carcinogen...

Probably not much besides CO2.

Re:Eh

[ShooterNeo]

Unless you're heating your dwelling with electrical resistance heating, which is the worst and most expensive form of heat there is, the excess heat from incandescents is not doing your energy bills any favors. Each unit of heat emitted is about three times as expensive as the equivalent BTUs from burning natural gas or using a heat pump. So in effect it's still costing you money to use incandescents, but you only save ~2/3 to ~3/4 as much money as you'd think if you replaced those incandescents with CFLs.

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!

Re:Bu.. bu.. but...

[glwtta]

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

In this case the drawback is that they produce a light spectrum that makes you want to stab yourself in the eye after prolonged exposure.

I know, it's a small nit-pick. I'm probably just trying to justify my foregone decision to not change my "not stabbing myself in the eye" habit.

Re:Bu.. bu.. but...

[lotho brandybuck]

Let me try to help...

Packaging large amounts of vacuum in incandescent lamps and CRTs increases the concentration of air we've got to breath if we're not living in a lamp or CRT.

Switching to these so-called green technologies could see us run out of air!!!

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:Easy Bake Ovens

[MichaelSmith]

I once blew up ten old style 20mA LEDs by mis configuring a bench top power supply. I got some heat out of the arrangement but you wouldn't want to eat the cake afterwards, or for that matter breathe the air.

Re:I haven't had great luck with CFLs

[Cimexus]

Yeah it seems like CFLs are a great example of YMMV.

I simultaneously replaced all lights in my home with CFLs three years ago. Good quality ones with a nice spectrum similar to old style incandescents (to my eye, at least).

Since then how many have failed? Only one.

I must say I'm quite impressed. Even the outdoor ones haven't died yet (exposed to a typical yearly temperature range of almost 50C). I wouldn't ever go back to incandescents ... and frankly LEDs look even better (less waste heat, potentially better spectrum and range of colours).

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.

Re:Legislation

[Cimexus]

Incandescents are already 'banned' in many areas of the world (including where I live). That is to say, stores aren't allowed to sell new ones anymore (existing ones that are still going are OK obviously). The exception to this is weird form-factor lights that they don't mass-produce CFLs for (e.g. those little ones you put into bedside tables). But for standard overhead light fittings, incandescents have already gone the way of the dodo here.

Even factoring in the impact of recycling, their total lifecycle environmental impact is considerably less than incandescents. Many vendors that sell CFLs (e.g. hardware stores) also accept back dead ones. And if not, I just pop the dead ones in a box in the back of the car and take them to the dump next time I'm in that area anyway, so the 'extra' travel is minimal. For me at least, it's worth it. My electricity bills are at least $100/year less after moving to CFLs, and they produce less waste heat (which matters to me as I don't have AC!)

LEDs will be better though of course. They should be trashable just like incandescents were, while retaining the energy savings of CFLs.

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.

Power factor?

[RecessionCone]

I wonder if this analysis took into account CFL's poor power factor. Cheap CFLs usually have a power factor of around 0.5, which causes substantial electrical losses compared to Incandescent bulbs, which are purely resistive (and therefore have a power factor of 1.0). LEDs, on the other hand, have a pretty good power factor. http://www.theengineer.co.uk/opinion/led-is-the-answer/299821.article

Re:Power factor?

[sFurbo]

As most household appliances are inductive loads and CFL's are capacitive, their 1 power factor actually improves the overall power factor of a home, so if anything, CFL's will slightly reduce the electric loses.

Coefficient of Performance

[AlpineR]

Wikipedia says: "When used for heating a building on a mild day, a typical air-source heat pump has a COP of 3 - 4, whereas a typical electric resistance heater has a COP of 1.0."

So, yes, contrary to popular belief, resistive heating is a terrible waste. Burning the coal in a potbelly stove would be a little better then burning it in a power plant to generate electricity to transmit (with losses) over power lines to heat a wire near your ceiling. But using it to drive a refrigeration cycle would be a far better use of the energy.