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LEDing It Hang Out: The Downside of Higher Efficiency

It's not news that the venerable incandescent light bulb, which has served us so well for over 100 years, is on its way out. Through a combination of legislative mandates, local building-code imperatives, and operating-cost pressure, there's been a sequence of phase-outs, starting with 100W bulbs and working down to 75W, 60W and so on. (Strictly speaking, these rules don't exclude incandescent bulbs, they just require that bulbs achieve certain efficiency levels which incandescents can't meet; if you could come up with a sufficiently efficient incandescent bulb, you'd make a fortune.)

This isn't the place to argue the technical virtues and vices of LEDs and CFLs as replacements, or the broader economic and environmental effects; those are discussions for another time and place. But as the switchover proceeds, it's interesting to review how the 90% inefficiency of the incandescent bulb — and the resultant heat it gives off — was actually used to advantage in many applications. There have been many reports, such as a recent one from Canada (see “Incandescent bulb ban leaves bird care centre with dim hope“), where the basic 100W bulb was used as a heating element that was cheap, easy to obtain, and easy to replace when it burned out (as most heating elements do).

Even better, as a resistive load, the incandescent bulb is easy to control and regulate. No matter that it has a highly nonlinear input/output transfer function — as long as you have a closed loop with a temperature sensor in the system, you had the makings of a pretty decent controllable heater.

The law of unintended consequences (one of my favorite “laws”) even extends to low-cost, mass-market items such as the Hasbro Easy-Bake toy oven, which the company has been making for decades with minimal few changes. Key to the design was the use of a standard bulb as the heating element; again, it was cheap, easy to source, easy to replace. However, the oven had to be completely redesigned with a custom heating element in place of the bulb (see “Easy-Bake loses its bulb, gets a makeover“). While in the broader scheme of things, this is just a toy and redesigning it is not a major disruption, I'm sure there are many applications where such a redesign or retrofit is a far bigger deal.

Reality is that there are many times where the downside of a product or technology has been flipped around and used to advantage. One of the many lessons I took away many years ago from the excellent 1978 TV series Connections by James Burke is that in most cases, progress comes when an application adapts advances or developments from other, unrelated areas — even the ones with shortcomings. (If you haven't seen this series, I urge you get to get it as a DVD, or look for the YouTube segments; it's well-done, educational, and also thought-provoking.)

To those who welcome the loss of the incandescent bulb and its severe inefficiency, I wonder: what else is being lost with it, via attributes and roles that you don't recognize? Have you ever been involved in a design where you took advantage of what everyone else saw as a weakness of a component or approach, and actually used it to your advantage?

This article originally appeared in EBN's sister publication EDN .

15 comments on “LEDing It Hang Out: The Downside of Higher Efficiency

  1. prabhakar_deosthali
    January 25, 2014

    With the incandescent bulbs , designing of load banks for testing of electrical systems is very easy.

    I think the legislation should only ban the use of incandescent bulbs for lighting, it should allow its use for such other purposes as load banks, heating element and so on where it is used as electrical load.

    Just to make sure that the bulbs are not used for lighting, they can be manufactured with black glass instead of the transparent or milky ones.

  2. Hailey Lynne McKeefry
    January 25, 2014

    @prabhakar, i wouldn't have thought of this approach (black bulbs). It seems like it might work, but to the idea of unintended consequences of design decisions here are some questions:

    1) by banning regular bulbs, would the price of those bulbs go up as shipments went down? What would be the impact of that? Price increases could take this inexpensive alternative and make it expensive.

    2) black colored bulbs: would adding this coating add a lot of cost in terms of extra manufacturing steps, more testing whatever?

    I think that we go to legislation rather than common sense too often in the modern world. Should we really make them illegal?

  3. Hailey Lynne McKeefry
    January 25, 2014

    Just read this:

    The demise of the incandescent bulb might come as a surprise to most Americans, however. A recent study by Lutron pointed out that fewer than 1 in 3 adults (just 28 percent) were aware of the planned phase out. A similar Socket Survey by Sylvania showed slightly more awareness — 4 in 10 were aware of the phase out, it revealed.

     

    Before you read this article had you heard about this?

  4. Eldredge
    January 25, 2014

    @Hailey – Yes, I knew about the incandescent light phase-out. I am a little surprised that the awarenes is as low a quoted in the Lutron study.

     

  5. Eldredge
    January 25, 2014

    Legislative mandates often seem to be the author of unintended consequences. In the absence of such mandates, the free market is very efficient at selecting the technologies (old or new) that function best. Having a wide range of available technoligies from which to choose increases the available options.

    While there are legitimate reasons for mandates, they always serve to place limitatios on formerly available options, and consequences (intended and unintended) ensue.

  6. Daniel
    January 26, 2014

    “It's not news that the venerable incandescent light bulb, which has served us so well for over 100 years, is on its way out. Through a combination of legislative mandates, local building-code imperatives, and operating-cost pressure, there's been a sequence of phase-outs, starting with 100W bulbs and working down to 75W, 60W and so on.”

    Bill you are right that incandescent lamps are gradually phasing out. Initially CFL made a strong presence in lue of incandescent lamps and now the turns are for LEDs. As a part of green building concept, LED and OLEd are widely using with star rated buildings, because of the low energy consumption and less energy wastage. As of now the drawback of LEDs are its higher prices, which comes up to twenty times of the ordinary buld of same wattage (Illuminent).

  7. ahdand
    January 27, 2014

    @Jacob: Do you think its possible ? I feel since there is more draining while using wifi the charging will not make a big impact at all.

  8. Daniel
    January 27, 2014

    “Do you think its possible ? I feel since there is more draining while using wifi the charging will not make a big impact at all.”

    Nimantha, I feel this comment is not relevant to this topic about LEDs and lighting systems.

     

  9. Daniel
    January 27, 2014

    “I think the legislation should only ban the use of incandescent bulbs for lighting, it should allow its use for such other purposes as load banks, heating element and so on where it is used as electrical load. Just to make sure that the bulbs are not used for lighting, they can be manufactured with black glass instead of the transparent or milky ones.”

    Prabhakar, why peoples prefer LEDs and CFL for lighting? This is mainly because of its power efficiency and low wastage, but at the same time advantages in power wastages are using in bakery ovens and incubators. There heat dissipation is important than lighting.  My question/ concern is when other technologies are there with better heat efficiency at a low power, whether we really requires incandescent lamps for this purpose.

  10. Geoff Thomas
    January 29, 2014

    As a discrete heating source the old incendescent bulb is cheap, except when it starts a fire, – I notice that in modern laminators, eg A4 size are sold as little as $20;But i am talking here of the heating elements therein, – two long strips already wired up and with an LED to indicate on and an automatic thermostat to keep the temperature constant, – rarely do laminator heaters fail, usually it is the rollers jamming or the motor, – thousands are thrown away every day, probably the factory that makes the heating element could be induced to make them available separately from the laminator itself at a much lower price.

    Just a thought.

    Cheers,

    Geoff.

  11. rsanders
    January 29, 2014

    RED coating on an incandescent lamp, to allow a portion of visible light while eliminating use as 'general' illumination, is MUCH preferred to any 'black' or light-blocking use. And other colors than red should continue to be available.

    Black: There are other 'unintended consequences' based on natural biological responses when animals are involved; rather than a black, no-light approach. For decades, incandescent lamps specifically meant for use as infrared heat sources have been 'dipped' to provide mirror-coating around the base (top, when installed inverted pointed downward) area, and with a cheap RED glass tint on the otherwise clear filament area that actually aids in the transmission of heat.

    You will immediately recognize them in heater-fan combination fixtures in restrooms. They emit a red light, rather than being 'blacked out', which allows the maximum infrared heating transmission along with a small amount of red visible light.

    Red glowing lighting has proven to be a natural attractant for especially the baby animals that seek out the red lighted area even when it is being mimicked by red LED lighting that provides NO heat. This is being tested by some commercial farms that use electric warming mats, which are typically black, to naturally 'urge' the infant and delicate animals to move over to the warming mat where their survival will be enhanced. The warming mat uses less energy than the typical 175W lamp used previously, but the animals do not appear to 'remember' or automatically find where the mat and warmth is until after a few days of life, and it is those first few days of life that matter most for survival.

    Allowing 'any' screw-base incandescent lamp to be produced and sold at any wattage so long as it is fully dipped or tinted in 'some color' (including red) of 'at least ##% optical density' would be a suitable exemption to eliminate the non-lighting uses problem, including as a cheap indicator, resistive load, and for warming/heating.

     

     

  12. ahdand
    January 30, 2014

    @Rich: True cheap devices do have faults. So its always better to look into the reliability and the quality aspects as well without going for the cost only.   

  13. Eldredge
    February 5, 2014

    I'm surprised that wasn't cited as one of the primary reasons to change to the more efficient and safer mercurey-doped version. Well, maybe I'm not surprised.

  14. deBayou'Gator
    March 17, 2014

    Safer? Pardon me?  I hope your tongue was in your cheek when you wrote that comment.

    Fluorescent lights require special disposal, not just 'cause the mercury is easy to convert, in nature, to highly poisonous mercurous salts, but because the phosphors on the inside of the tube are toxic (e.g., but not limited to, carcinogenic).

    Moreover, CFLs are limited in the same way as incandescent lamps: they require a(n electrically) heated filament to operate at all.  Filaments burn out.  In the year after I replaced 8 of 10 incandescent bulbs with new CFLs, I had to replace 6 of the CFLs but just 1 of the incandescents…and the latter had been in use for almost 10 years.  Greater efficiency is irrelevant if the lamp dies too soon.

    The only downside to LEDs is that they're expensive to make.  On the upside, I've seen figures that estimate the useful life of some recent lamps as 100,000 to 300,000 hours.  The reason is that there's no filament to vaporize and fail.  Early versions DID fail because they caught fire and toasted themselves.  That's been corrected by transforming the incoming voltage to a lower value, improving the efficiency even further.

  15. Eldredge
    March 18, 2014

    @deBayou'Gator – Yes – my tongue was firmly embedded in my cheek! Trying to pull it back out now.

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