Toast, soon
EETimes.com – Cree white LED produces 131 lumens per watt — FYI
MANHASSET, N.Y. — Cree Inc. said it has produced a white LED with efficiency of 131 lumens per watt, confirmed by the National Institute of Standards and Technology.
“This is the highest level of efficacy that has been publicly reported for a white LED and raises the bar for the LED industry,” said Scott Schwab, Cree general manager, LED chips, in a statement.
Semiconductor suppliers have racing to produce higher efficiency white LEDs as the industry seeks energy-efficient alternatives to conventional lighting. In March, Japan-based Nichia Corp. reported it had developed a white LED rated 100 lumens per watt.
Last September, Cree (Durham, N.C.) said its white XLamp 7090 Power LED was capable of producing 86 lumens per watt.
Lumens-per-watt is the standard used by the lighting industry to measure the conversion of electrical energy to light. As a reference, conventional incandescent light bulbs are typically in the 10 to 20 lumens per watt range, while compact fluorescent lamps range from 50 to 60 lumens per watt.
I guess the downside being that they were initially expected to cost considerably more than standard bulbs until they went into mass production.
On the positive side, though, the amount of electricity saved using one of these ought to be pretty hefty. Enough to have a serious impact on how many new power plants will need to be built in the near term, emissions from coal burning plants, etc.
On the down-down side? Your next door neighbor might not take down their Christmas lights by Easter. Or the 4th. Or Halloween. Or EVER.
“But you swore you’d only ever use your power for good!”
Eat that, Edison! :-p
How much electricity would be saved if incandescent light bulbs were totally phased out in America and replaced with LEDs and high efficiency florescent?
It’s got to be a tremendous amount, right?
I wonder if it would be better public policy to subsidize energy efficiency this way than to build nuclear power plant?
I wonder if someone could crunch the numbers on that one.
#3, or just schedule a future ban on incandescent light bulbs, similar to how we have forced limits on how much water can be used to flush a toilet.
I think the savings would be very substantial. Just cities changing lighting (street lamps and traffic lights along with municipally owned buildings) over to led lighting would save enormous amounts of energy. The LED bulbs last much longer and use far less energy. Hopefully the savings would be passed on to taxpayers. Perhaps even create a ripple effect. If people realised the direct connection between this type of lighting and reduced taxes hopefully they would adopt the technology as well.
I would be more then willing to make the complete switch, even if the LED bulbs were more expensive. It’s tough phasing out incandescent totally when there are not that many alternatives, been trying to switch out all the bulbs in the house to those longer lasting fluorescent bulbs.
The plus side on making the switch is usually the comparative savings I see on the initial month’s electric bill, which usually cancels out the upfront costs of the bulbs.
Greg Allen… numbers:
Taking a comment from an IEEE interview that an incandescent bulb is a 95%-efficent heater that happens to give off light…
Assume 250 million people in the US. Assume that 80% of those people are indoors and require one 60-watt lightbulb to be lit 12 hours a day.
That’s 667 Wh per day per person X 200 million x 365 days per year…
35,350 GWh per year. At 5 cents per kilowatt-hour (conservative, by any means), the average household (4 people) would save only $50 per year — assuming that they pay all their own electrical costs.
And, of course, this is assuming that no one is using flourescent bulbs, which tend to be more expensive but more energy efficient.
Calculations of savings should consider the reduced AC costs becuase those bulbs aren’t heating our homes, but that would be offset to some degree by increased heating costs in the winter becuase those bulbs aren’t heating our homes.
Savings would vary considerably depending on the geographic location of the consumer. In the south, we spend considerably more money in the summer trying to keep cool, than we spend in the winter staying warm. Further, electrical heating, wheter by lightbulb, or other means, is almost universally more expensive than other forms. The replacement cost of the equivelent heat from the bulbs is less than that of the electricty saved.
Are they (LCDs) dim-able by typical triac-based dimmers?
That depends on the nature of the backlight electronics. Dimming doesn’t help as much as you think, it’s better to generate light with a higher efficiency. (Or use a display technology that doesn’t require a light source.)
#7
But $50 a year times a few million is some real money.
Hhmmm, where are all the libertarians shouting that they want the choice to buy and use the biggest damn incandescent bulb possible, to go along with their Expedition.
On another note, incandescent bulbs have a warm light that does effect moods. Fluorescents are known to contribute to Seasonal Affective Disorder (SAD). How would LEDs effect our psyche?
One problem. LED’s are diodes. Light Emitting Diodes. Diodes only allows electricity to in one direction, that’s why they require DC and not AC. If you want to use LED’s to light up your house you’ll need a rectifier and smoothing capacitor to go from AC to DC. You will also need a transformer becuase 220V or 110V won’t be appropriate for LED’s. All of this will cost money.
13,
LEDs actually produce “whiter” light than flourescent lamps. Not only that, if you use red, green, and blue LEDs to make the white light it’s even “whiter” (by definition). With RGB LEDs one can even adjust the color temperature of the white light to obtain the desired mood.
14,
Everything in your house outside of your major appliances use dc as well. What do you think those wall-wart power supplies that come with every consumer product do? There is a frightening amount of energy wasted in the linear power supplies scattered through every home, which is why there are new power supply efficiency regulations being put into place in California and other states.
The real answer is to eventually put a standard 12-V dc bus into every home (a single large rectifier at the box would do the trick) to power all the devices that require dc from your cell phone to your diode-illuminated HDTV monitor.
Jeff,
Thanks for the hard numbes.
I gather, then, that banning filament lighting isn’t going to allow us to build many fewer power plants. Still, it seems worth it in the long run.
15: “The real answer is to eventually put a standard 12-V dc bus into every home (a single large rectifier at the box would do the trick) to power all the devices that require dc from your cell phone to your diode-illuminated HDTV monitor.”
Excellent point, and 12 volt DC is also easily supplied by cheap, off-the-shelf sealed-lead acid batteries and not-too expensive solar panels. With drastically reduced power requirements for 12 volt appliances such as LED lights, a solar panel can actually light a home. That would be for nearly free.
With LED lighting and electric cars replacing petroleum cars, we could — really, we could, as a recent report said just using hybrids would do it — cut oil usage to the point where we only need US and Canadian sources of crude. Independence!
16: If we can repeal four articles of the Bill of Rights and get tens of thousands of people killed for control of the oil supply, we can ban incandescents. After all, there’s this war against evil in which no stone should be left unturned…
“An average American home has about 30 light bulbs, 3 of them burning for 5 hours or more per day. If all American homes replaced just 3 of these bulbs with long-lasting bulbs, Americans could save electricity equivalent to the output of 11 fossil-fuel-fired power plants. In turn they would eliminate about 23 million tonnes of CO2 emissions per year – and save about $1,800,000,000.
ref: Natural Capitalism by Hawken, Lovins and Lovins.”
From http://www.banthebulb.org
>cut oil usage to the point where we only need US and Canadian >sources of crude.
Except the less oil used, the more dependent we’ll be on Middle East oil. The local oil is too expensive to produce for the most part, so we;ll just be using those low cost suppliers in the gulf. Maybe if they opened up AnWR and built some new refineries we could be less dependent.
Its ironic that many of you mention wiring homes for DC. It was Thomas Edison that favored DC over AC and that LEDs, that will eventually kill his incandescent bulb, needs DC to run.
Dont know if this has been posted…
BUT.
A White LED has a tendancy to sap Night vision, and is only 1 NARROW wave-length.
They are now looking at home lighting, and trying to find a combination of Light frequencies that will NOT harm the eyes.
Brian (18) – thank you – Jeff’s (7) numbers for lightbulb time seem extremely low – I’d budget at least 4 times that – and $200 a year isn’t huge savings, but at least it’s not pocket change … course, I live in the cold, dark north, where we use a lot of lighting.
21: A white LED is a regular LED (according to various websites, blue or long wave UV) that causes a phosphor (like what’s in a fluorescent bulb) to glow white, which is by definition not a single wavelength. Newer white LEDs are closer to true white than the older ones, which were bluish white.
White LEDs do sap night vision, because they’re white. So do light bulbs and fluorescents. To preserve night vision, astronomy and military flashlights use red LEDs or incandescent bulbs with red filters.
#15, Smartalix. Thank you for the reply. This and your other posts explain your moniker.
#17, catbeller, Kudos to you for an equally good response.
#19, AB CD, still trolling.
#20, gq, Edison’s proposed DC power grid failed because there is a much higher line loss with DC then with AC. Edison’s plans would have required many more power stations to supply all the local needs.
Jeff and brianthesmurf
You both missed out on the enormous amount of lighting used by industry.
Buildings are lit to a major degree. Although they use fluorescent lighting, which while more efficient than incandescent, is less efficient than the LEDs.
Sandia National Labs and US DOE estimates that by 2025, 50% of lighting-related electricity usage could be replaced, savings of 760 GW.
Alleviating 133 new power stations (1000MW each) and eliminating 258 metric tons of CO2.
Furthermore, a substantial portion of office air conditioning/mahinery electricity costs are related to cooling down the impact of the fluorescent lights.
I have read that the combination of lighting and lighting-related cooling costs is responsible for 40% of the electricity demands of commercial buildings.
Elsewhere I have read that lighting is responsible for 7% of total US energy consumption (electricity plus transport); not including airconditioning necessary to dissipate lighting-caused heat)
Further, Toyoda Gosei, Toyota’s equivalent of GM’s Delphi, estimates that using LEDs to replace all their cars lighting (headlights, rear lights, internal indicator lights) would be the equivalent of dropping the weight of their mid-sized vehicles by 660 lbs (20%), which translates into approximately a 20% reduction in gasoline consumption. This fact alone is mind blowing. This is a result of the inefficiency of the alternator at converting combustion into electric charge.
My guesstimate is that the savings from widespread implementation of LEDs (and assuming that state of art LED lumen/watt efficiency already is 10-fold better than incandescent and double fluorescents) – residential and commercial lighting and associated airconditioning cost reductions plus incorporation of LEDs into cars, trucks, buses would cut almost 20% of the energy usage in the US.
whoops i mis-typed the CO2 savings:
it’s 28 million metric tons.
Just now found this site.
#14 and #20: AC works just as well as DC if a pair of LEDs are connected reverse-parallel ( head to tail).
(each lights up twice as bright half the time, so they don’t overheat.)
#15 and #17: Like the stack of batteries in a flashlight, LEDs can be stacked in series to match whatever voltage is available.
Instead of trying to get AC changed to DC in households why not just add a circuit in the base of the “light bulb”. Since LEDs operate at voltages well below 12vdc and draw a known current, a simple voltage regulator circuit is not only elegant but cheep, it would be a resister (or voltage divider – suggest design for 130 vAC) full wave bridge rectifier for DC and a filter cap, or a diac/triac circuit to feed the LED and should work even with a conventional incandescent dimmers – in mass maybe 25 to 50 cents per “lamp” or a custom chip at say 5 cents per in very large quantities. Since LEDs have a life of 100,000+ hours and because of the low current there is very low heat in the base, the base (i.e. medium, candela etc) containing this circuit becomes a through away part of the light. Note that these lites could also contain multiple LEDs as designated for high intensity lighting, three-way lights, soft reading, full spectrum daylight, amber bug lites, etc; and packaged in shapes that consumers are accustomed to using. Additionally offer a version to run from 12v for RV / boating / camping as well as converted household wiring.
Regards,
Michael Dick
133 lumens per watt is GREAT, and I know it will only get better as more research money is poured into LEDs. Lighting is said to be a $12 BILLION dollar business in the US alone, so with that much money on the table GE, Phillips, and others will be butting heads to see who can get their products on store shelves first. Unforfunatly it will be several years until we see any of these in a store. If you want to try some LED replacement bulbs now about the best prices I have found were at http://www.shop.donsgreenstore.com and they were even offering free shipping. So while we wait to pay homage to the big corporate lighing companies there are a lot of small sellers with LED bulbs right now.
I am missing one crucial figure: Was the record-breaking 131 lm/W 131 lm per input Watt (=consumed Wat)t or was it 131lm per Watt converted to light? It does make a difference, as the efficiency used to be about 27%!
Mike