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Wednesday, January 13, 2016

The latest in energy saving light? The incandescent light bulb

Forget the mercury-laden CFL or the LED, which gives off light like it is the 1950s. MIT has dusted off the incandescent light bulb, insulated the filament, and voila, reinvented the light bulb.

From MIT:
The key is to create a two-stage process, the researchers report. The first stage involves a conventional heated metal filament, with all its attendant losses. But instead of allowing the waste heat to dissipate in the form of infrared radiation, secondary structures surrounding the filament capture this radiation and reflect it back to the filament to be re-absorbed and re-emitted as visible light. These structures, a form of photonic crystal, are made of Earth-abundant elements and can be made using conventional material-deposition technology.
That second step makes a dramatic difference in how efficiently the system converts electricity into light. One quantity that characterizes a lighting source is the so-called luminous efficiency, which takes into account the response of the human eye. Whereas the luminous efficiency of conventional incandescent lights is between 2 and 3 percent, that of fluorescents (including CFLs) is between 7 and 15 percent, and that of most compact LEDs between 5 and 15 percent, the new two-stage incandescents could reach efficiencies as high as 40 percent, the team says.
The first proof-of-concept units made by the team do not yet reach that level, achieving about 6.6 percent efficiency. But even that preliminary result matches the efficiency of some of today’s CFLs and LEDs, they point out. And it is already a threefold improvement over the efficiency of today’s incandescents.
The team refers to their approach as “light recycling,” says Ilic, since their material takes in the unwanted, useless wavelengths of energy and converts them into the visible light wavelengths that are desired. “It recycles the energy that would otherwise be wasted,” says Marin Soljačić, professor of physics.
Just remember, Congress mandated CFL and LED at the behest of industry.


  1. I moved from incandescent to CFL and now LED because I hate to change light bulbs. Also, since I'm in a wheelchair there are some bulbs I have to have other people change so CFL and LED are more convenient for me.

  2. I went LED too, except the light is glaring. CFL sucks

  3. I went out and stocked up on incandescent light bulbs. I have enough 60, 75, and 100 watt light bulbs to last the rest of my lifetime. - Elric

    1. Ditto. I bought boxes of incandescents of every variety I need for eternity. Funny thing is, I haven't had to replace a single one of my existing incandescents since then. It's as if the existing ones are hanging on just to spite the new ones I bought as their replacements. Good on them, I say!

    2. I stocked up, too. One light uses a bulb about every other month but it's on about 12 hours in 24. I'll leave the leftovers to someone in my Will.

    3. I also stocked up, have a closetful of various wattages. I get migraines from CFL and LED bulbs.

      Will states like KY, VA, and TN get those jobs back in the production of new incandescents?

  4. After they outlaw clothes dryers, most of your electric bill will be taxes.