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LEDs emerge to challenge fluorescents as bulbs may be pushed from lighting throne

By Associated Press

Thursday, May 10, 2007

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NEW YORK (AP) -- The light bulb, the symbol of bright ideas, doesn't look like such a great idea anymore, as lawmakers in the U.S. and abroad are talking about banning the century-old technology because of its contribution to global warming.

But what comes next? Compact fluorescent bulbs are the only real alternative right now, but ''bulbs'' that use light-emitting diodes, or LEDs, are quickly emerging as a challenger.

LEDs, which are small chips usually encased in a glass dome the size of a matchstick head, have been in use in electronics for decades to indicate, for example, whether a VCR is on or off.

Those LEDs were usually red or green, but a scientific breakthrough in the 1990s paved the way for the production of LEDs that produce white light. Because they use less power than standard incandescent bulbs, white LEDs have become common in flashlights.

Established players in the lighting industry and a host of startups are now grooming LEDs to take on the reigning champion of residential lighting, the familiar pear-shaped incandescent light bulb.

The light bulb has been running out of friends recently. California and Canada have decided to ban the sale of incandescent bulbs by 2012. Australia is banning them in 2010. The European Union is looking at banning production of the bulbs. A U.S. Senate committee is working on a proposal that would phase out the light bulb in 10 years.

And in New Jersey, where the first practical incandescent bulb emerged from Thomas Edison's laboratory in 1879, a bill has been introduced to ban their use in government buildings.

Governments are gunning for the light bulb because it's much less efficient than fluorescents, using about five times more energy to produce the same amount of light.

Lighting consumes 22 percent of electricity produced in the U.S., according to the Department of Energy, and widespread use of LED lighting could cut consumption in half. By 2027, LED lighting could cut annual energy use by the equivalent of 500 million barrels of oil, with the attendant reduction in emissions of carbon dioxide, the gas believed to be responsible for global warming.

Much of that reduction would be possible with today's technology, using compact fluorescents, or CFLs. But consumers haven't warmed to them. The light quality hasn't been satisfactory, most take time to turn on and aren't dimmable.

The LED has advantages over the CFL in most of those areas, and judging by this week's Lightfair trade show in New York, it could be a serious challenge to the CFL in a few years. What holds it back is chiefly price, but LEDs are already an economic alternative for niche uses.

Story continues below

In the last two years, the diodes have doubled in energy efficiency and brightness, according to Greg Merritt, director of marketing for Durham, N.C.-based LED-manufacturer Cree Inc. In particular, LEDs that produce a yellowish or ''warm'' light similar to incandescents have improved.

Dallas-based Lighting Science Group Corp. showed an LED ''bulb'' that screws into a standard medium-sized socket and produces a warm light equivalent to that of a 25-watt incandescent bulb, but consumes just 5.8 watts. It costs $50, hardly palatable to consumers who can buy a standard bulb for less than a dollar.

Comments

  • What about the waste heat?
    Do the energy saving calculations take into account that most incandescent lights are running at night, in winter time?  In most countries we will also be heating our houses by other means and the result of using energy-saving light bulbs will be that the house thermostat (which, of course, has been turned down a degree or two :)) will cut out a few seconds later, largely negating any energy savings.

    My personal (unscientific) experience with fluorescent replacement bulbs is that they are much dimmer than their stated incandescent equivalents and that claims for 10x extended life are greatly exaggerated.
    Rate this comment: 12345

    chrisjmiller
    05/14/2007
    Posts:26
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    4/5
    • Re: What about the waste heat?
      Hi, Chris.  I have seen this comment posted by various persons in various forums concerning fluorescent or LED lighting vs incandescent.  I would be VERY interested in seeing any "numbers" available about the lose of ambient home heating attending a switch away from incandescent bulbs -- and, of course, the hypothetical heating trade off.  Thanks.

      RTTedrow
      USDOE [ret.]
      Rate this comment: 12345

      rttedrow
      05/14/2007
      Posts:41
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      4/5
      • Re: What about the waste heat?
        Hi RT and thanks to all for your helpful explanations.

        I was really just wondering aloud whether the arguments against incandescent bulbs have been overstated.  In calculating the energy savings I guess (and would be prepared to wager) that they are as simplistic as saying that replacing a 100W bulb by an 'equivalent' 20W will save 80 Joules of energy for each second the light is on.  I accept that gas or oil heating is more efficient than electric (but what about the greenhouse gases?) and that air-con in summer (not a requirement here in the UK ;)) diminishes the effect (though lighting is in use much longer in winter than in summer), but it's still there.

        The point about comparative manufacturing impacts is also well made.  Incandescent bulbs are made from cheap non-toxic materials that are readily available.  The same is not true of their 'electronic' replacements.
        Rate this comment: 12345

        chrisjmiller
        05/15/2007
        Posts:26
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        4/5
    • Re: What about the waste heat?
      Using heat directly from a chemical source is at least twice as efficient as heat from an electrical source.  For those with electrical heating systems, well, there's a sucker born every minute.
      So, really, even if you have to provide another couple hundred watts of heat because your lighting provides only visible light, you're going to help the environment.
      That $50 price tag, though... I have no idea where they came up with it.  A quick search with Google shows $9 products (1.3W, 18 LED, I'd expect around 1000 Candela) which could replace appliance bulbs.  a $95 price tag gets a 11,000 Candela Flood light  usign just 5W or so.  But $ represent fiddling careful work in electronics, bad yeilds, and significant investment in production equiptment.  Every $, in the end, is environmental drain, or fiddling work, or both.
      More volume always translates, in electronics, into lower cost, as the line is amortized over more units.
      Rate this comment: 12345

      wizwom
      05/14/2007
      Posts:8
      Avg Rating:
      4/5
    • Re: What about the waste heat?
      The heat not added to a space durring the air conditioning season will balance or exceed any positive heat gain.  As an architectural lighting designer, I have been directed to reduce the lighting load so additional AC units are not required while I have never been asked to add more lighitng so a heater would not be needed.

      There are much beter reasons to argue against this policy.  It is narrowly perscriptive.  A beter direction is to set a minimum  efficacy (lumen/watt) standard and if incadecent (or more likely their halogen cousins) can meet that standard then we can continue to use them while being more efficient.  LEDs are not the magic cure all.

      Charles Cameron, IES, Assoc. IALD
      Rate this comment: 12345

      chuckcameron
      05/14/2007
      Posts:2
      • Re: What about the waste heat?
        Agreed, what these stories always fail to mention is the quality of light (especially color rendering) of these products.  The CF lamps that are aimed at the home market have tended to be very poor in this category.  I fear the same with LED's.  Not all white LED's, even when they are supposed to be the same color, will have the same color rendering capabilities.  Also, the home market will be the first place that bad products which don't manage heat well will be sold, causing the LED lamps to fail quickly & likely resulting in people moving away from them (as many have from CF).
        Rate this comment: 12345

        dvgmacdonald...
        05/14/2007
        Posts:1
  • Manufacturing overhead?
    what is the manufacturing overhead for each particular type of device? no one seems to look at the total energy used to produce a bulb of ether type or LED at the factory, how about the Co2 output to produce a bulb compared to a LED, what is the comparison on resources used to manufacture the device that then probably wont be recycled in any way.

    And when those questions are answered perhaps we can look at comparing the manufacturing overhead for each device and its total energy use in the devices lifetime.
    Rate this comment: 12345

    Viv
    05/14/2007
    Posts:12
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    3/5
  • Contribution to Global Warming?
    I like all the news about the LED developments and I watch this technology with great anticipation. However, I have difficulty with the article starting out with the statement, "...as lawmakers in the U.S. and abroad are talking about banning the century-old technology because of its contribution to global warming."

    It is not clear to me nor is it supported in this article what the documented contribution from incandescent light bulbs is, in fact, to global warming. It seems that too many news articles are using this as the a foundation for an argument and the peer-reviewed research seems to be inconclusive or lacking.

    Go LEDS! But I resent the jumping on the global warming bandwagon.

    TheWhale
    Rate this comment: 12345

    TheWhale
    05/14/2007
    Posts:1
    • Re: Contribution to Global Warming?
      Focusing on the politics and the looks like this: Banning of the cheap incadenscent bulb will be a regressive tax to the poor who won't as easily afford the more expensive CP bulbs or LEDs.  The politicians then will subsidize the poor with "advanced technology" payments to be used for retrofitting the home, funded in part by an energy waste tax which will be levied against those bulbs that don't meet an annual energy efficiency rating criteria indexed to some political target.  Black market incadenscents will hit the streets.  "Hey bub, want to buy a bulb?"  Energy police will scan houses with thermal monitors and will start levying fines, and building inspectors will issue discrepancies.  Supply and demand will take a backseat to legislative fiat. 
      The knee-jerk reaction to perceived man-made cause of global warming again is causing politicians to make bad decisions.  Perceived because other planets, Neptune and Mars, without our help, are experiencing global warming.  BTW, Quantum Dots may eclipse LEDs.
      Rate this comment: 12345

      RD
      05/14/2007
      Posts:112
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      3/5
  • Some comments
    Hi!
    I have with great interest red your comments . I'm from Scandinavia and here houses are generally very well insulated . Most houses use electricity in an indirect way for heating . That means heatpumping either from the air or ground . One unit of electricity can give up to 5 times the energy in the form of heat . Thus it is always efficient to use as effective light devices as possible !!!

    Then it is another question if so called low energy lamps really are more mean and lean . If one does an energy calculation on power for manufacturing and balances it for better longevity and lumen/watt and the equation comes out favorable to the "low energy" alternative then it is a no brainer . or is it ???
    Rate this comment: 12345

    scandiviking
    06/02/2007
    Posts:1

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