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Lifecycle Energy Costs of LED, CFL Bulbs Calculated 400

Posted by kdawson
from the pla-hol dept.
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.
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Lifecycle Energy Costs of LED, CFL Bulbs Calculated

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  • Re:Great assumption (Score:3, Informative)

    by Rising Ape (1620461) on Tuesday December 01, 2009 @12:38AM (#30279352)

    Or they never work at all.

  • Oh for fucks sake (Score:3, Informative)

    by ArchieBunker (132337) on Tuesday December 01, 2009 @12:42AM (#30279396) Homepage

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

  • by hedgemage (934558) on Tuesday December 01, 2009 @12:55AM (#30279478)
    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.
  • by ShooterNeo (555040) on Tuesday December 01, 2009 @12:59AM (#30279500)

    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.

  • by timeOday (582209) on Tuesday December 01, 2009 @12:59AM (#30279506)

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

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

  • by texas neuron (710330) on Tuesday December 01, 2009 @01:30AM (#30279690) Homepage
    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.
  • by Galactic Dominator (944134) on Tuesday December 01, 2009 @01:58AM (#30279860)

    Can we stop with dumbasses giving health advice?

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

  • Re:Eh (Score:1, Informative)

    by Anonymous Coward on Tuesday December 01, 2009 @02:19AM (#30279952)

    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.

    The toxic parts of a LED are not in your home, they are at manufacturing where they can be dealt with (given proper regulation) or buried underground. In contrast, CFLs bulbs have mercury but more importantly they have toxic fire retardant chemicals. People forget this, but it's required since CFLs would otherwise sometimes burst into flames.

    I had one that cracked while on, releasing mercury (supposedly not so hazardous as people hype it to be) and another where the plastic melted into an orange smoldering mess. So I've already been exposed to more toxic compounds from CFLs than if I used LEDs for the rest of my life. Just for some context.

  • by whoever57 (658626) on Tuesday December 01, 2009 @02:34AM (#30280014) Journal

    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.

  • by innocent_white_lamb (151825) on Tuesday December 01, 2009 @04:25AM (#30280522)

    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:Power factor? (Score:4, Informative)

    by sFurbo (1361249) on Tuesday December 01, 2009 @05:13AM (#30280790)
    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.
  • by Inda (580031) <slash.20.inda@spamgourmet.com> on Tuesday December 01, 2009 @08:03AM (#30281730) Journal
    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.
  • Re:Eh (Score:1, Informative)

    by Anonymous Coward on Tuesday December 01, 2009 @08:28AM (#30281850)

    No way to replace overhead lights with them? You are using older generation LED lights and have obviously not used the newer LED lights! I already light my house with them, and they are indistinguishable from incandescents. I purchased these lights from here:

    http://www.lightplanet.co.uk/led-light-bulbs/60-watt-replacement-led-bulbs-c-321_335.html

    I also have a 40 watt equivalent desk lamp using 3 LED bulbs that is very bright from here:

    http://www.goecostore.co.uk/led-light-bulbs-1062-0.html

    The costs per bulb are around £15-20, but will easily pay for itself over its 100,000 hour lifespan. For a technology site, it never ceases to amaze me how many posters on slashdot just don't keep up with technology advancements and post opinions based from their experience with older stuff! LED household lighting is her now, decent and affordable!

  • Re:Great assumption (Score:4, Informative)

    by Muad'Dave (255648) on Tuesday December 01, 2009 @08:59AM (#30282044) Homepage

    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 [ledsmagazine.com] shows a Vfwd vs temp graph of an LED junction temp of 120C.

  • Re:Great assumption (Score:5, Informative)

    by Alioth (221270) <no@spam> on Tuesday December 01, 2009 @09:08AM (#30282088) Journal

    [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 (Score:5, Informative)

    by LanMan04 (790429) on Tuesday December 01, 2009 @09:38AM (#30282306)

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

  • by AlpineR (32307) <wagnerr@umich.edu> on Tuesday December 01, 2009 @10:47AM (#30283068) Homepage

    Wikipedia says [wikipedia.org]: "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.

  • Re:Great assumption (Score:3, Informative)

    by sgtrock (191182) on Tuesday December 01, 2009 @11:01AM (#30283268)

    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 (Score:2, Informative)

    by johno.ie (102073) on Tuesday December 01, 2009 @11:04AM (#30283352)

    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 (Score:4, Informative)

    by jeffmeden (135043) on Tuesday December 01, 2009 @11:39AM (#30283786) Homepage Journal

    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 (Score:4, Informative)

    by James McP (3700) on Tuesday December 01, 2009 @12:12PM (#30284250)

    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.

  • by Orne (144925) on Tuesday December 01, 2009 @12:56PM (#30284870) Homepage

    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 [epa.gov]

  • Re:Great assumption (Score:1, Informative)

    by Anonymous Coward on Tuesday December 01, 2009 @03:46PM (#30287646)

    1) There are compact fluorescents that have straight tubes (actually U-bend, but not spiral), which is what grandparent is most likely referring to (more popular in Europe than the States?).

    2) Traditional, non-compact straight fluorescents don't use transformers (or inductive chokes) anymore. Instead, they use electronic control gear which basically does the same thing as the electronics in a CFL (except that it's not integrated with the fluorescent tube). Electronic control gear drives the tube at a high frequency (tens of kHz), eliminating flicker and improving efficiency. Warmstart control gear enables fluorscent tubes to be turned on and off at will without reducing lifetime, and eliminates startup flicker (startup happens in 0.5 - 2 s, depending on the control gear). Some control gear units have digital (e.g. DALI) or analog (e.g. 1-10V) control interfaces, which enables dimming control. A control gear unit lasts 50,000 to 100,000 hours, and costs from 10 to 60 eur a piece (depends on the model).

  • Re:Great assumption (Score:3, Informative)

    by fractoid (1076465) on Tuesday December 01, 2009 @10:12PM (#30292534) Homepage

    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 (Score:2, Informative)

    by Jeprey (1596319) on Thursday December 03, 2009 @04:42PM (#30315772)
    > 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

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