The Next Big (Light Bulb) Idea

Erica Rowell, today’s guest blogger, is a Web Editor and Producer at Environmental Defense, and our resident expert on light bulbs.

Ever stop to wonder why, since the mid-1990’s, traffic lights don’t seem to burn out? They can’t be using old-fashioned incandescent bulbs – those burn out all the time. Maybe they switched to longer-lasting compact fluorescent lights (CFLs)? Nope. Today’s stop lights use light-emitting diodes (LEDs).

LEDs last 35,000 to 50,000 hours – five times longer than the average CFL, and 50 times longer than an incandescent bulb. In fact, because the technology is so different, they don’t really ever burn out. They just get dimmer over time – a long time. Today’s LEDs produce more light per watt than conventional bulbs but they’re not quite as efficient as CFLs… yet. On the plus side, unlike CFLs they contain no mercury whatsoever.

You can find LEDs in all kinds of places – flashlights, television remotes, car headlights, flat screen displays, exit signs and even holiday lights, just to name a few. So, thinking of buying some LED light bulbs?

You can, if price and selection are no object. Though LEDs have been used in niche applications for a decade, the technology is still evolving for general-purpose light bulbs. The Lighting Science Group is about to release a 15W equivalent globe bulb [PDF] that will screw into a standard socket, but it will cost $50. Other LED lamps are slowly coming to light, too, including Lucesco’s Halley light, a winner from 2006’s Lighting for Tomorrow LED competition.

Obviously, prices need to come down, and for that reason, mass-market LED light bulbs are still 5 to 10 years away. And because their light is so directional, it remains to be seen whether they’ll be able light up a room like incandescent bulbs and CFLs. But many scientists and lighting experts hold out hope that LEDs are the future of lighting.

In the meantime, by all means switch to CFLs. Our guide can help you find ones to fit in different places and give off different kinds of light. By the time they burn out, LED light bulbs should be available – and more affordable.

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  1. cstirnckwr
    Posted December 6, 2007 at 4:33 am | Permalink

    Dear Erica,
    You noted that:
    “Obviously, prices need to come down, and for that reason, mass-market LED light bulbs are still 5 to 10 years away. And because their light is so directional, it remains to be seen whether they’ll be able light up a room like incandescent bulbs and CFLs.”

    1) At current, the CFLs are much cheaper than they used to be, & at the same time, while they are touted to last for 5-7years, they frequently fail within a year — which necesitates the saving of a lot of receipts — assuming that they will be honored.
    That is — the price of the CFLs has markedly decreased, at the same time as a ‘built in obsolescence’ has been incorporated into them — what a surprise!(I actually have an old CFL bulb that has been going for well over 10 years — while none of the ‘new’ ones have approached it)

    2) So, with the ability to give enough light that they can be used in car headlights, I don’t think that the bottleneck for LEDs is in their difficulty in providing light — I tend to think that it rather lies in their working much too well!!!
    ie. at 50->100,000 hours per bulb, with a lot less use of electricity, I don’t think that there is a real rush to get a conventional ‘home’ bulb to the market — & it will likely be forced only by some co. that can make one outside the patent etc. restrictions.

    3) For example, lets consider whether a LED ‘spot’ bulb would be so restrictive in not giving off ‘general light’, that it couldn’t be used. Most of my bulbs are ones that I want to focus on work that I am doing, & not interfere with peripheral areas(eg. a computer screen) — so for a lot, that shouldn’t be a problem.
    Furthermore, if a more diffuse light was needed, at least one cheap possibility would be to put a diffuser in front of it.

    4) If CFLs now have transformers built into their bases, it shouldn’t be too hard to ditto rectifiers to convert AC to DC for the LED lights(if that is finally necessary) — & I would think that ‘solid state’ ones should already be ‘off the shelf’ — so making the transition to a ‘home’ bulb shouldn’t be much of a problem.
    That is, I doubt that all of the electricity that is currently powering LED NYC traffic lights, NYC Christmas bulbs(on trees & bridges)etc. is DC — Westinghouse won out over Edison in the ‘transmission’ fray a long time ago.

    5) While LED are indeed expensive, I actually don’t really know why. I don’t know their means of fabrication, but my notion is that they can be ‘printed’ so that their ‘masking’ & ‘interference’ ‘holes’ that coerce the photons into certain radiant/visible frequencies shouldn’t be anywhere near as complicated as the ‘masking’ etc. printing that goes into computer boards.
    So while finding out the ways to get a ‘complete spectrum’ might be difficult, the implementation of what is already at hand should be again, almost ‘off the shelf'(except for patent or other voluntary restrictions).

    6) So as for the general assessment that it will likely take another ‘5->10 years’ to do any of this, has got to be only things being deliberately put ‘on the slow track’.
    In ‘5-10 years, we’re likely to have a completed space station, & operational somatic derived ‘stem cells’ — & this is not anywhere near as complex.

    7) I guess what I’m suggesting to ED, is that maybe this ‘5-10 years’ scenario really shouldn’t be accepted, & that with a little directed effort, LEDs for the home, at a more or less reasonable cost, for at least some significant ‘niches’ of use, should almost be available tomorrow.
    & this would be a HUGE saving for the environment, in all respects!

    Sincerely — joel schiff — cstirnckwr

  2. cstirnckwr
    Posted December 6, 2007 at 11:59 pm | Permalink

    A ‘follow up’:
    Just bought a Chinese produced, LED Spot Light that will directly screw into the ordinary ‘home’ light fitting, & is supposedly able to be ‘dimmed’ — for ~$16(incl tax.) in NYC.

    A CFL that can be dimmed was $17 — likely to produce a lot more light, but not last nearly as long, & use substantially more energy.

    The LED is listed as a PAR 20, 36 LED, rated to last 20,000 average hours, & uses 1.8 watt.
    The light emitted is the usual ‘flourescent blue-white’ like light, with the package showing that at:
    7ft. it yields an 18ft. ‘cone’ of light, at 10 lux
    10ft. yields a 28ft. ‘cone’ of light, at 6 lux.
    I am using it as a desk lamp. At about 2 1/2ft. away from my computer keyboard, it is fairly dim, with the guesstimated equivalence of an ~40Watt incandescent bulb., and a restricted ‘cone’ of illumination.
    While it would be good to get much more light, at present it is sufficient to illuminate my keyboard, easily read printing/notes that are put under it, & not glare off of the computer screen.

    The 7 LED flashlight that I keep in my car is immensely valuable in reading roadmaps at night — much better than the usual small flashlight.