Did you know... (led)

Rahz

Well-Known Member
That LED is the only light source with a future?

That it's theoretically possible to reach 100% efficiency?

And not just theory but fact. We won't be buying 100% efficient cobs any time soon, but it's already been achieved on a very small scale in a college laboratory.

Any you know what happens when an LED get's close to 100%?

It starts drawing in heat from the environment, and emitting it as light! That's right, LEDs can be driven at over 100% efficiency. Such emitters rather than needing heat sinks will help cool the driver.

:eyesmoke:
 

SPLFreak808

Well-Known Member
Can i get a link to this cold diode with no resistance and no voltage drop? *edit sorry read it wrong. Where did you read this theory though? At 100% efficiency, it would no longer be a diode or what a diode was designed for. Also,100% means that will be a crazy intense light putting out an enourmous amount of radiant heat from a tiny source. Im not sure if they can isolate the heat emitted from the light alone from lowering efficiency
 
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SupraSPL

Well-Known Member
http://gizmodo.com/5890719/scientists-create-230-percent-efficient-led-bulbs

synopsis
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.097403

discussion
http://physics.stackexchange.com/questions/22030/can-someone-explain-the-science-behind-mits-230-efficient-leds

criticism by jalmy:
"This thing is basically a very low powered heat scavenger that produces light as a byproduct. It is not a violation of entropy to convert excess heat into electrons or in this case photons which could be converted to electrons with panels. In any event the system loses heat and would stop working at some point if you didn't bring in more heat."
 
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churchhaze

Well-Known Member
When there is 100% efficient led.
I shall claim infinite grams per watt yield in grow room.
May be i can burn a piece of charcoal to produce heat to power LED and provide co2 for plants.:fire:
Unfortunately this wouldn't be true. Even a 100% light source takes power. To generate 100W of PAR, you would need to consume 100W of electricity.
 

EfficientWatt

Well-Known Member
Yeah amazing, saw that some time ago.. BUT

Those 100%+ leds are tiny as you said, and need to be spaced out, so would'nt work for cobs. In addition, extremely low temperatures were used, if I remember correctly.
Also, it's a color led... phosphors on white leds/cobs cause considerable losses, hard to overcome if you want to get close or above 100% efficiency ..

As we get close to 100%, efficiency gains won't be as appealing , as increases will be less significative.
20% => 25% represents a 25% light increase, per W.
50% => 55% represents a 10% light increase, per W.
90% => 95% is only 5.5% more light per W.

When there is 100% efficient led.
I shall claim infinite grams per watt yield in grow room.
May be i can burn a piece of charcoal to produce heat to power LED and provide co2 for plants.:fire:
g/W has been going on for literally millenniums, its called 'outdoor growing', in respect to your electricity network it's g/W :eyesmoke:

:peace:
 
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PurpleBuz

Well-Known Member
http://gizmodo.com/5890719/scientists-create-230-percent-efficient-led-bulbs

synopsis
http://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.097403

discussion
http://physics.stackexchange.com/questions/22030/can-someone-explain-the-science-behind-mits-230-efficient-leds

criticism by jalmy:
"This thing is basically a very low powered heat scavenger that produces light as a byproduct. It is not a violation of entropy to convert excess heat into electrons or in this case photons which could be converted to electrons with panels. In any event the system loses heat and would stop working at some point if you didn't bring in more heat."

BUTTTT you have to count the heat into the energy equation, so the physicists are playing games for a headline

I could see using a low powered heat scavenger to get rid of excess heat in a sealed grow room, but I'll be dammed if I'm gonna supply heat to drive lights.
 

FranJan

Well-Known Member
That LED is the only light source with a future?

That it's theoretically possible to reach 100% efficiency?

And not just theory but fact. We won't be buying 100% efficient cobs any time soon, but it's already been achieved on a very small scale in a college laboratory.

Any you know what happens when an LED get's close to 100%?

It starts drawing in heat from the environment, and emitting it as light! That's right, LEDs can be driven at over 100% efficiency. Such emitters rather than needing heat sinks will help cool the driver.

:eyesmoke:
To me these are the only lights with a future. LEDs or really OLEDs and a few variants will survive as little lights for our dashboards. Maybe. Now if LED wants to keep re-inventing itself, like COBs or what is going on with non-rare earth based white lighting then maybe.

http://www.enlightenmentmag.com/led-update/laser-vs-led
"Will white-light laser diode systems one day surpass LEDs in general illumination? Some experts say “yes,” and others “no.”

"LEDs have power-conversion efficiencies (PCE) today of 70 percent, while laser diodes (LDs) are currently at 30. Paul Rudy, Advisor & VP/Business Development at Soraa® – a manufacturer of full-spectrum GaN on GaN LED lamps – explained that in the short-term, laser diode systems are significantly less efficient compared with LED systems. However, there are very rapid efficacy improvements in LDs, year over year. Rudy estimates LD efficacies have doubled over the last five years — and are not slowing down. After years of development, Soraa is now going to market with its first laser diode production, competing with OSI and Nichia.
Another large advantage of laser diode systems are their ability to emit very tight beams, placing more of their light output on an intended target. This can result in lower output requirements. Rudy points out that laser efficiency at putting light on target could allow laser systems to compete with LEDs long before their power-conversion efficiencies catch LEDs."

http://www.zmescience.com/science/physics/first-white-light-laser-03255432/
Cooooool.

http://phys.org/news/2015-08-single-crystal-phosphors-suitable-ultra-bright-high-power.html
 

frica

Well-Known Member
When there is 100% efficient led.
I shall claim infinite grams per watt yield in grow room.
May be i can burn a piece of charcoal to produce heat to power LED and provide co2 for plants.:fire:
Why not candlelight?
Provides CO2 and good deep red in the meantime. :-)
 
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