Researchers lay out vision for lighting 'revolution'
December 18, 2008
If all of the world's light bulbs were replaced with energy-efficient LEDs for a period of 10 years, researchers say it would reduce global oil consumption by 962 million barrels, reduce the need for 280 global power plants, reduce carbon dioxide emissions by 10.68 gigatons, and ultimately result in financial savings of $1.83 trillion. Credit: Rensselaer/Kim and Schubert
A "revolution" in the way we illuminate our world is imminent, according to a paper published this week by two professors at Rensselaer Polytechnic Institute.
Innovations in photonics and solid state lighting will lead to trillions of dollars in cost savings, along with a massive reduction in the amount of energy required to light homes and businesses around the globe, the researchers forecast.
A new generation of lighting devices based on light-emitting diodes (LEDs) will supplant the common light bulb in coming years, the paper suggests. In addition to the environmental and cost benefits of LEDs, the technology is expected to enable a wide range of advances in areas as diverse as healthcare, transportation systems, digital displays, and computer networking.
"What the transistor meant to the development of electronics, the LED means to the field of photonics. This core device has the potential to revolutionize how we use light," wrote co-authors E. Fred Schubert and Jong Kyu Kim.
Schubert is the Wellfleet Senior Constellation Professor of Future Chips at Rensselaer, and heads the university's National Science Foundation-funded Smart Lighting Center. Kim is a research assistant professor of electrical, computer, and systems engineering. The paper, titled "Transcending the replacement paradigm of solid-state lighting," will be published in the Dec. 22, 2008 issue of Optics Express.
Researchers are able to control every aspect of light generated by LEDs, allowing the light sources to be tweaked and optimized for nearly any situation, Schubert and Kim said. In general LEDs will require 20 times less power than today's conventional light bulbs, and five times less power than "green" compact fluorescent bulbs.
If all of the world's light bulbs were replaced with LEDs for a period of 10 years, Schubert and Kim estimate the following benefits would be realized:
-- Total energy consumption would be reduced by 1,929.84 joules
-- Electrical energy consumption would be reduced by terawatt hours
-- Financial savings of $1.83 trillion
-- Carbon dioxide emissions would be reduced by 10.68 gigatons
-- Crude oil consumption would be reduced by 962 million barrels
-- The number of required global power plants would be reduced by 280
With all of the promise and potential of LEDs, Schubert and Kim said it is important not to pigeonhole or dismiss smart lighting technology as a mere replacement for conventional light bulbs. The paper is a call to arms for scientists and engineers, and stresses that advances in photonics will position solid state lighting as a catalyst for unexpected, currently unimaginable technological advances.
"Deployed on a large scale, LEDs have the potential to tremendously reduce pollution, save energy, save financial resources, and add new and unprecedented functionalities to photonic devices. These factors make photonics what could be termed a benevolent tsunami, an irresistible wave, a solution to many global challenges currently faced by humanity and will be facing even more in the years to come," the researchers wrote. "Transcending the replacement paradigm will open up a new chapter in photonics: Smart lighting sources that are controllable, tunable, intelligent, and communicative."
Possible smart lighting applications include rapid biological cell identification, interactive roadways, boosting plant growth, and better supporting human circadian rhythms to reduce an individual's dependency on sleep-inducing drugs or reduce the risk of certain types of cancer.
To read the full paper, visit: http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-16-26-21835.
Source: Rensselaer Polytechnic Institute
Nov 05, 2009 |
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Luxim? If you need one for a projector, street light or spot light you can buy them now. If you're looking for off the shelf, edison-screw socket light bulb replacements, that has never been promised and may never come. It would require scaling down from some 250 W(some ~40 times brighter than a standard 60 W light bulb) to 6 W or so; nobody ever said it could be done.
What's needed is some creativity, and lots of marketing for this to go somewhere.
http://www.led-li...gory=LED Bulbs
There are already a huge variety of LED bulbs available so it's only a matter of time for the price to drop and sales will increase greatly.
In the "LED World", anything over 1000 mcd (approx. 3 lumens at 120 degree radiant angle)is considered as high intensity. The average 60 watt incandescent emits around 14.5 lumens per watt (850 lm), while today's most modest high intensity LEDs average about 72 lumens per watt...they are at least 4 times more efficient.
A regular light bulb radiates its waste heat around its entire exterior, but LED emitters have much more stringent heat management restrictions in order to ensure the lifespan of the emitters. It is much more detrimental for an LED light to overheat than it is an incandescent, since by nature the incandescent is a heating element!
Call me if LED's efficiency ever approaches that of flourescent.
A 100W equivalent LED bulb costs $100.
Electric cost is 15c/kWh = 0.15$/kWh. (estimated)
So power saving is 100W - 10W = 90W = 0.090kW.
Money saved per hour = 0.15 x 0.090 = 0.0135$/h
Usage of 6 hours per day.
0.0135 x 6 = 0.081 $/day.
Bulb pays for itself = $100 / 0.081 = 1234.569 days
Years to break even = 3.4 years
This sounds like it is cost justifiable right now!
I just need to look at my bill to get my actual electric cost rate.
I agree.
If you can find a 10 W, 180-190 lm/W LED light for $100(which is what you are implicitly claiming by saying that it's 10 times as efficient as an incandescent 100 W bulb) I would be very surprised.
Even if LED lights that cheap and that efficient are readily available, you're neglecting the opportunity cost. E.g. even if I have to buy several fluorescent tubes or CFLs over the life of the LED light and if they are high quality it could well total $100, as much of the LED, I don't have to pay that money up front. The fact that I don't have to pay that money up front means I can buy one fluorescent light now and do something productive with that money in the mean time; and there's always something productive you can do. I could pay down a bit on my student loans and avoid some interest payments; I could perhaps find an even bigger waste of energy that I can afford to replace now instead of later if I don't buy a LED lamp.
Additionally, LED lights for rarely used areas just plain don't make sense and won't for a very long time. In something like a toilet that you have lit maybe 15 minutes per day unless your suffering from some horrible stomach illness, it makes no economic sense whatsoever to use anything but incandescent lighting in the cheapest, crudiest lamp shade/socket possible.
-- Total energy consumption would be reduced by 1,929.84 joules"
~ 2000 J seems like the energy needed to lift my Chev truck 3 feet in one second. Surely all the light bulbs in the world are doing a bit more than that.
Those numbers don't make sense.
"global oil consumption by 962 million barrels"
That's 10 times the world's daily consumption. So 10 days of oil saved.
"reduce the need for 280 global power plants"
That's highly unlikely. That's about 1/3rd of the world's current power plants. That is unless they're referring to the most ancient and decrepit of plants.
"reduce carbon dioxide emissions by 10.68 gigatons"
And that is more than we release during the process of electricity generation the world over.
Last time I looked, a large percentage of all energy used for lighting went to commercial applications, which are all standard flourescent. And I have yet to find an AVAILABLE rational LED replacement which is as efficient as a standard flourescent.