LED with 230% Efficiency Developed @ MIT

MIT physicists have managed to create a Light emitting Diode that operates with greater than 100% efficiency!

http://www.wired.co.uk/news/archive/2012-03/09/230-percent-efficient-leds

 

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That sounds pretty awesome

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Changing the terms means changing the deal

Conceptually, this sounds like a potential paradigm shift.

The thing that gets me, in a larger context, is that when people discuss "energy efficiency" in terms of large-scale solutions, the discussion often becomes too compartmentalized. That is, sure, one particular system might only be able to achieve a certain efficiency, but one really ought to be able to distribute inefficiency in such a way as to make multiphasic energy production and distribution systems considerably more efficient than the marketplace has thus far found profitable.

I'm just sayin' ....

That is, when you start throwing around ideas that could include the phrase "cooling lamp", it's a whole new discussion.

 

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There's something here that the casual reader might easily overlook. Granted, 69 picowatts is VERY small amount of power (it's 69 trillionths of one watt if i have all my zeros right), but it's still energy.

And here's the implication that's easily missed: This device presents a mechanism for reversing entropy locally. Small scale, certainly, but a reversal nonetheless. Residual ambient heat is the final product of all energy-consuming activities - everything from a decaying tomato to all the stars in the cosmos which are eventually doomed to die someday (leading to what's called "heat death" of the universe when there is no longer a difference in temperature anywhere).

And apparently this thing can take that low-level (waste) heat energy and ramp it up to a considerably higher level. AND if the device can be scaled up or produced en mass and tandemed together, it could produce USABLE energy.

 

A pico refrigerator with an interior light to boot?

I can't wait to see the gigawatt version.

 

I am curious to know to what value the temperature drops, into fully insulated enclosure, inside which there is such a LED ?

 

All that is needed now is a solar power generator operating at over 50% efficiency, and Bingo!
Limitless free power.
Take that, perpetual motion machine deniers!

 

I also liked the adjoining article that popped up: http://www.wired.co.uk/news/archive/2011-06/10/hoverbike-chris-alloy

Anyone want to start a thread on this?

As to the LED, that appears to open a whole new vista of extracting ambient temperature energy and excreting it as photons, cooling down the device. Excellent way to make an air-conditioner that produces energy in the process. This might be the answer to the energy problem in the distant future, if this can be scaled -up and produced in large quantity.

 

I'm going to need to see the paper describing the measurement. If P = 39 picowatts and T = 300 K

\(\frac{P}{ \sigma T^4} = \frac{15 h^3 c^2 P}{2 \pi^5 k_B^4 T^4} \approx 8.5 \times 10^{\tiny -14} \, \textrm{m}^{\tiny 2} = 0.085 \, \textrm{\mu m}^{\tiny 2}\)

 

Likely that the reverse entropy begins to break down at large scales.

My first thought was embedding these LEDs in processors, essentially using them to dissipate some of the heat as light. Everyone seems to want these interior lighted cases anyway, might as well make it useful as well.

 

Heh-heh - except that you would gain practically nothing that way.

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Only the small amount of light that escaped the case would carry heat away; the rest of the light would be absorbed inside and return the heat right back to where it came from.

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Fiber optics then. You'd need the same thing with a refrigerator or air conditioning. I'd suspect the big issue would be, is the power consumption to run the LEDs worth the heat they absorb. If it's only a fraction of what can be accomplished with conventional means, then it's pointless.

But from a LED point of view, it's very practical, because there's usually extra heat to use somewhere.

 

What is meant by "The LED produces 69 picowatts of light..." ?
What is meant 1 watt of light? What kind of unit of measure is that?

 

It seems to be a genuine measure, although it is not one I have ever come across until now: http://www.answers.com/topic/light-watt

 

Measuring Light:
"There are many different units for measuring light and it can get very complicated. Here are a few common measurement terms:
Candela (cd):
Unit of luminous intensity of a light source in a specific direction. Also called candle.
Technically, the radiation intensity in a perpendicular direction of a surface of 1/600000 square metre of a black body at the temperature of solidification platinum under a pressure of 101,325 newtons per square metre.
Footcandle (fc or ftc):
Unit of light intensity, measured in lumens per square foot. The brightness of one candle at a distance of one foot. Approximately 10.7639 lux.
Lumen (lm):
Unit of light flow or luminous flux. The output of artificial lights can be measured in lumens.
Lux (lx):
Unit of illumination equal to one lumen per square metre. The metric equivalent of foot-candles (one lux equals 0.0929 footcandles). Also called metre-candle."

From the link:
"(optics) A unit of luminous power equal to the luminous power of light of a single wavelength λ whose radiant power is 1/Vλ watts, where Vλ is the value of the luminosity function at λ."

"photics The nominal unit in the reciprocal ratio of the efficacy of a source of light to the maximum efficacy of 680 lm·W-1, which occurs at a wavelength of 555 nm (for the light-adapted eye). (The reciprocal of this maximum, i.e. 1.47~ mW·lm-1, is the mechanical equivalent of light.)"

But:
radiant power:
"luminous flux: A measure of the radiant power of light emitted from a source without regard for the direction in which it is emitted. It is measured in lumens."

I can not find a correlation between power consumption (electrical) and power of light.
It is only a reference to the maximum efficiency (so far) of 680 lm / W

 

A watt is a measure of power, which is energy per unit time - and you can express light as energy.

To get light power in watts, take all the photons the thing produces a second, multiply by h/2*pi, then multiply by frequency.

 

lol....

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Wow, a lightbulb that will help my A/C cool the place!

Groovy.

 

Might be useful for optical computing, fast operation, low power consumption and helps reduce heating. Win-win.

 

I'm wondering if it would be possible to make a huge array of tiny LED systems. Scale each individual down in size to where you could fit billions on a sheet. They by linking millions of sheets, you could scale-up the process. I can just see such a system immersed into warm air, cooling it down, while at the same time emitting a beam of light targeted towards a photovoltaic grid to produce electricity. What an amazing thing that would be, to simply convert ambient temperature into utilizable electricity.

The principle is similar to OTEC, I believe. But instead of a colder 'heat sink', the quantum principle of converting ambient heat into a photon allows for the photon to carry away that energy at above-unity efficiency. It in essence radiates photons into space, making it the equivalent of a heat-sink.

While it took decades to miniaturize transistors, it might take decades to make this into a practicable device. But it does appear theoretically possible. Comments anyone? RP? Prom? AN?