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Photonic Structure Increases Light Bulb Efficiency
An Anonymous Coward writes "A new experimental microscopic tungsten lattice
can increase the efficiency of an incandescent
electric bulb from 5 percent to greater than
60 percent. This is done by converting waste
heat into visible light. "
My understanding is that they said that IR-frequencies are synonymous with "heat". They frequently used the term black-body radiation. I remember IR-HEAT being associated with green-house effects; the angle of refraction is low for IR and glass, for example. So when sunlight enters your car (at a direct angle), it bounces off things but hits the glass on the inside at too great of an angle, and thus bounces back inwards, amplifying the total heat.
Not that I'm satisfactorily answering your question, but throwing out some food for thought.
-Michael
-Michael
The coolest element of them all..
If you don't belive me read the book "Uncle Tungsten".
Great book, a must for anyone remotly intrested
in chemistry or the history of chemistry.
Ok, so it's a shameless plug.. but I just had to push that damn fine book.
Three-dimensional (3D) metallic crystals are promising photonic bandgap structures: they can possess a large bandgap, new electromagnetic phenomena can be explored , and high-temperature (above 1,000 C) applications may be possible. However, investigation of their photonic bandgap properties is challenging, especially in the infrared and visible spectrum, as metals are dispersive and absorbing in these regions. Studies of metallic photonic crystals have therefore mainly concentrated on microwave and millimetre wavelengths. Difficulties in fabricating 3D metallic crystals present another challenge, although emerging techniques such as self-assembly may help to resolve these problems. Here we report measurements and simulations of a 3D tungsten crystal that has a large photonic bandgap at infrared wavelengths (from about 8 to 20 m). A very strong attenuation exists in the bandgap, 30 dB per unit cell at 12 m. These structures also possess other interesting optical properties; a sharp absorption peak is present at the photonic band edge, and a surprisingly large transmission is observed in the allowed band, below 6 m. We propose that these 3D metallic photonic crystals can be used to integrate various photonic transport phenomena, allowing applications in thermophotovoltaics and blackbody emission.
Doesn't this look like some explanation: the material (unlike metals) has a bandgap, i.e., is insulating and cannot absorb or emit radiation at low frequencies. So the energy has to be dissipated at higher (visible) frequencies. Apparently the output is higher than naive calculations would predict. So the puzzle is not why the frequency of the emitted light is so high, but why the output is so strong for a given temperature.
light bulb wastes power
tungsten evaporating:
produce more photons!
A 60% efficient incandescent bulb would have a whole lot of applications beyond just saving money on the power bill.
Think projector lamps: Think about the waste heat they wouldn't generate. Think about the cooling fans they won't need. Imagine a 40-watt bulb throwing as much light as a 500 watt bulb does today.
I sure hope this hits the market sometime SOON.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
Much more profound though is that they're basically talking about a device that converts heat into light: The ramifications and applications of that are wide ranging and staggering. Getting even more "goofy", could you have a heat->light conversion, followed by a light->electricity conversion? (i.e. a small "heat energy recovery system").
The science of turning electric power into light has really changed in the past decade. I've seen a graph in one of my engineering trade journals showing the efficency of LEDs in lumens per watt. Just a decade ago, the best LEDs were two orders of magnitude less efficent than flourescent bulbs. Now, the new generation of blue and white LEDs are more efficent than flourescent, and are approching the levels of low pressure sodium lights.
If we extrapolate from the given 5%->60% levels given in the article, that would raise incandescent lights to nearly the levels of flourescent, without the warm-up time flourescent has.
Now, the problem with LED vs. flourescent is cost - LEDs are much more expensive in terms of lumens per doller than flourescent. Would microstructured tungsten be any cheaper?
www.eFax.com are spammers
Incandescent lamps... around 20 lumens per watt. Fluorescent lamps... about 70 lumens per watt. White LED, 50 lumens per watt and climbing. And the power requirements and ability to fit them into small spaces are much less tricky than for fluorescent.
LED's are almost there--and efficiencies are climbing. Main problem right now is that they're expensive. But already, I see they're being used for the red, and, increasingly, the green lights in traffic lights around here.
By the time this stuff makes it out of the lab, LEDs will be cheap and even more efficient than they are now.
And, of course, all the gee-whiz wizards-of-the-labs articles never say how much the new technology is likely to COST. And the stated efficiencies tend to decline as the devices start to approach reality...
If they can really make these things twelve times as efficient as LED's AND give a pleasant, flattering light spectrum AND get the cost down, it will be interesting.
"How to Do Nothing," kids activities, back in print!
Granted this is on the heels of the bubble fusion article
But this is superlatively revolutionary. Take the two possible big-hit applications: massive energy efficiencies coupled with a 20-30% increase in photovotalic efficiency (read: reduced cost) and this is a big step toward alternative energy.
Imagine a mass-produced fuel cells and increased efficiency photovotalics with lighting generated by these things. Who needs a power company?
Hey, I'm just your average shit and piss factory.
Because some idiot decided that there needed to be 3600 seconds in an hour, and so using a 100W device for an hour somehow uses 360kJ of energy.
If your target audience uses a calculator to get fifty percent of a hundred, you don't want to inflict our silly Sumerian time scale on them. (Was it the Sumerians who did the base-sixty nonsense? Or was that the Babylonians?)
--grendel drago
Laws do not persuade just because they threaten. --Seneca