# LED lights are going to be outdated - already?



## DougA (Mar 29, 2015)

Interesting article here about how graphene lights are going to replace LEDs with lower power consumption and lower cost to buy.  Supposed to go on sale next year.

http://www.bbc.com/news/science-environment-32100071


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## Jeepman401 (Mar 29, 2015)

DougA said:


> Interesting article here about how graphene lights are going to replace LEDs with lower power consumption and lower cost to buy.  Supposed to go on sale next year.
> 
> http://www.bbc.com/news/science-environment-32100071



I tried some early LEDs (Walmart branded Lights Across America I think) and was disappointed in the quality. Most went dead the first year, I sure the newer name brand ones are much better. But looking at the current draw vs CFLs with equal lumes they just don't make since to me. Maybe these may be better dollar wise...


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## woodgeek (Mar 29, 2015)

The article says adding graphene will lead to a 10% improvement to existing LED designs, not clear what that means.  There is already a huge spread in lumens/W among LED bulbs (from <70 to >110).

I think the 'filament' models will take over above 100 lum/W, frosted or clear, and look just like an old Edison bulb.  The helium filled bulb cooling method works great when the amount of heat to be rejected drops below a threshold (as lum/W increases).  The packaging has to be cheaper too....very little metal.

The latest 115 lum/W ones I got recently are blowing the doors off my L-prize and Cree bulbs, and clearly running a lot cooler.  Now close to 2x as eff as CFL.  And the physical limits suggest that we can reasonably get to 150-250 lum/W.   That is like a 60W replacement using 3-4W.

In ten years we could have bulbs that look just like Edison bulbs, all glass, clear or frosted, but they will come in 2, 3 and 5W sizes, to replace the old 40, 60 and 100W sizes.


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## Ashful (Mar 29, 2015)

I've recently purchased a couple of LED bulbs, but find the availability of bulbs to match the lumens of 25w and even 35w incandescents is really not there, at least on my local store shelves.  Not everyone wants 75w or 150w equivalents!

I'd be very happy if LED or graphics mfg's would offer more low-wattage and decorative bulb replacement.  We have more than 200 bulbs in our house, all pretty much below 50w.


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## woodgeek (Mar 29, 2015)

have you tried googling 'LED filament bulbs' yet?  Right now the US market is filled with lower-wattage Chinese versions in 'decorative' formats, and the high W replacements are hard to find.  I'm not endorsing their longevity, but it might be fun to try out a few.

I suspect the big boys (cree, phillips, seimens) will be all over this format in a few years.


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## Jeepman401 (Mar 29, 2015)

woodgeek said:


> The article says 10% better than current LEDs.  There is already a huge spread in lumens/W among LED bulbs (from <70 to >110).
> 
> I think the 'filament' models will take over above 100 lum/W, frosted or clear, and look just like an old Edison bulb.  The helium filled bulb cooling method works great when the amount of heat to be rejected drops below a threshold (as lum/W increases).  The packaging has to be cheaper too....very little metal.
> 
> ...


Current draw of new style LEDs on their packaging is about what my CFLs use on my Kill-A-Watt meter. I am using "daylight" color not old style yellow light. What bulb are you using and what does it cost? Current draw?


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## woodgeek (Mar 29, 2015)

Jeepman401 said:


> Current draw of new style LEDs on their packaging is about what my CFLs use on my Kill-A-Watt meter. I am using "daylight" color not old style yellow light. What bulb are you using and what does it cost? Current draw?



this thread: https://www.hearth.com/talk/threads/if-you-miss-those-incandescent-filaments.142331/

I got a 7W, non-dimmable, warm-white 60W replacement, clear.  Nominally 800 lumens at 7W.  Haven't verified either number, but brightness seems right to my eyes, and its not getting very warm at all, compared to my Crees.

Of course, it cost me $20, unlike the $6 crees.  Everyone needs a hobby.


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## jebatty (Mar 29, 2015)

I think I'm going to wait to replace incandescent bulbs until a replacement comes along at very low cost that converts the ambient energy fields into light and uses no electric power at all. BTW, I'm typing this on my friend's computer because I'm still waiting for faster, cheaper, smarter, better looking, completely intuitive device comes along -- oops, might already have that in my BFF (not cheaper though).


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## DougA (Mar 29, 2015)

I'm anxious to get rid of all my CFLs.  We've replaced dozens of incandescents with CFLs and many are not lasting any longer than the old incandescents yet cost way more.  I bought a few that take half a minute to get bright enough and switched them around into fixtures that we leave on most of the time to eliminate the problem.

I buy LEDs in the US when visiting at $5. ea on sale. Here in Ontario, they are about $12. on sale, then you get a $5. gov't rebate. I HATE rebates like that because stores bump the prices up to make more $$.  Just wrong

I found the last 6 LEDs I bought have had a good color temperature and look similar to the old bulbs, which I prefer.


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## Jeepman401 (Mar 29, 2015)

My CFLs last many years, some were over 8 years old when I switched them with the new daylight color. Had a friend 3 houses down and he said they burned out fast, but they had kids also. All the good quality LEDs I see at Menards etc are $20-$40 each. Just not worth the savings at that price. Now I may switch, if these new ones are around 4 watts, I use CFLs now that pull around 14 watts each vs 65 watt reg bulbs.


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## BrotherBart (Mar 29, 2015)

The article says they are looking at the material for false teeth too. I will hold out for incorporation of lighting into the dentures.


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## jebatty (Mar 29, 2015)

Our house was all CFL's for a long time. I never had the experience that I read so often of others that many CFL's would last only a short time. And I always bought the cheapest CFL's. Maybe 1 in 20 would crap out, and then rather quickly, the rest would last "forever." We still have 13W pin-tube CFL's in our recessed kitchen fixtures, and all but one are original and these were installed in 1996 and still burning brightly.

Just pulled one pin-tube and it says it uses 220ma, that's 26W and not 13W on a 120V house circuit. Others I have tested on the Kill-o-watt always showed more watts than the 13W the CFL was supposed to use. What gives?

Now the kitchen CFL's are the only CFL's we still use, all other bulbs have been switched to 40 or 60W equivalent LED, most indoor to 3200-3400K color, some indoor 4000 or 5000K color, and all outdoor or garage 5000K color. Most dim just fine. None have failed yet and the longest being used now for about 1-1/2 years. And now when I see the very "red" incandescent or CFL that others use, I wonder why the strong red hue is liked so much when sunlight is even brighter than 5000K. Probably just because that was "normal" lighting since the late 1800's and people are used to an unnatural color. 

The most expensive LED's were $9 each, the least expensive before any rebates were $5 each. Again, I buy the cheapest. And I suppose when something better comes along, cuts power usage by about another 50% or so, I will switch lighting once again.


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## Ashful (Mar 29, 2015)

jebatty said:


> And now when I see the very "red" incandescent or CFL that others use, I wonder why the strong red hue is liked so much when sunlight is even brighter than 5000K. Probably just because that was "normal" lighting since the late 1800's and people are used to an unnatural color.


Try a few thousand years... fire, candles, and oil lamps, all similarly red color temps.

Old houses look odd when lit by CFL or LED.  New houses are generally very ugly, so by association... [emoji12]. (... a duck!)


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## jebatty (Mar 29, 2015)

.... ducked in the nick of time! Thanks for the warning. Does a 1956 house with natural 3/4" thick, 8-10" wide pine plank walls and 18" wide solid pine flooring qualify as old, new or indifferent?


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## EatenByLimestone (Mar 29, 2015)

New!   Now go to your corner!  



Like it has been with wood stoves, going from 40 grams of particulates per hour to 3 is going to be easier than getting that down to 1.  I'm sure lighting will be the same. 

 I switched half my house from cfl to led.  I only have 2 often used fixtures that haven't been swapped.  If the new stuff proves worthy I'd probably move the CFLs all the way out and transfer the LEDs to their spots.  Remember though, LEDs are now going to become cheaper as they are old technology.  Spending $200 to save 14 watts per hour across a house might not be a great deal.


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## DougA (Mar 29, 2015)

We can get LEDs in a wide variety of deg. K. I've got what is called warm white and I like them much better than the daylight ones.  

IMHO, daylight is great in an office or during the day but I prefer the warm white at home in the evening. Much softer on the eyes and the mind and my mind needs as soft as it can get.


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## RSNovi (Mar 29, 2015)

I have been buying the Sylvania recessed light LED retrofits and I really like them.  They replace the bulb and trim piece.


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## begreen (Mar 29, 2015)

I am patiently using up our collection of free CFL bulbs from the power company. In key areas I am also testing LEDs vs CFLs to see if they stand up to their longevity claims. All are warm white. Not sure which will last longer me or the bulbs.


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## ihookem (Mar 29, 2015)

I guess it is good to use even less energy and if you can find a way to do it for the same price, go for it. I really don't see the big deal going from a 800 lumen bulb from 7 watts to 4 watts. I imagine it takes 3-4 watts just ot get the electricity to the bulb... More efficient homes is where we should be focused on. We could save 10% of our heating/ cooling needs just by putting enough insulation in our attic..... Heck even new houses only require r 50 up here,, why not r60 while you are up there and its just old newpaper besides.


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## begreen (Mar 29, 2015)

Saving 3-4 watts doesn't seem like a lot until you look at the scale of consumption and the number of bulbs out there. If they can be produced even cheaper than other options that is also a big plus.

_According to fastcompany.com: "Last year, U.S. consumers spent about $1 billion to buy about 2 billion lightbulbs--5.5 million every day."
According to wsj.com: "The U.S., which has four billion electric lights using [incandescent] bulbs, represents about a third of the world market."
So, about 12 billion bulbs, worldwide._

12 billion times 3 watts is 36 gigawatts. A lot of power.


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## DougA (Mar 29, 2015)

I remember a few years ago that Ontario said they could shut down one power generation plant if everyone who owned an old beer fridge in the basement replaced it with a new model.


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## woodgeek (Mar 29, 2015)

ihookem said:


> I guess it is good to use even less energy and if you can find a way to do it for the same price, go for it. I really don't see the big deal going from a 800 lumen bulb from 7 watts to 4 watts. I imagine it takes 3-4 watts just ot get the electricity to the bulb... More efficient homes is where we should be focused on. We could save 10% of our heating/ cooling needs just by putting enough insulation in our attic..... Heck even new houses only require r 50 up here,, why not r60 while you are up there and its just old newpaper besides.



Gotta agree.  Going from 60W to 13W (CFL) is a *lot* more important than going to 9W (Cree LED 2014) or 7W (AXP LED 2015) or 4W in 2020.  But in the long run, the CFLs will burn out, and we'll all have nice bulbs that are more eff than any we have now.


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## EatenByLimestone (Mar 29, 2015)

I agree.  Just looking at my house, the 2 places I could save the most energy would be in the basement.  Either preheating my hot water with something like solar, which currently uses 20 therms of NG a month.  And insulating the block walls of my basement.  I'm not certain how much that would save, but I know this is my largest source of heat loss in the winter.


The problem with upgrading for higher efficiency is you get the low hanging fruit first.  Then you start chasing things with a longer breakeven and things that don't necessarily improve your standard of living.   How quick would you jump on an upgrade that saves $10 a month, but doesn't break even for 5, 10, 15+ years?  For me, 5 years I'll listen to the idea and consider it.  I might even jump if I see volatility coming in the energy source.  10 years I'll listen, but wait to see if something better is in the pipeline.  I'm not interested in 15 year paybacks for $10 a month, especially if the standard of living of my family isn't increased by it.


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## jebatty (Mar 30, 2015)

> How quick would you jump on an upgrade that saves $10 a month, but doesn't break even for 5, 10, 15+ years? For me, 5 years I'll listen to the idea and consider it. I might even jump if I see volatility coming in the energy source. 10 years I'll listen, but wait to see if something better is in the pipeline. I'm not interested in 15 year paybacks for $10 a month, especially if the standard of living of my family isn't increased by it.


This is quite rational on an individual decision making basis. But what if everyone in the world followed this practice: no mercury reductions, no reduction in sulfuric and nitric acid emissions, no reduction in particulate emissions, no decrease in CO2, etc. Coal would forever reign as king and health, quality of life, and the environment would degrade until we all and other living things, cockroaches excepted, live in squalor, disease, and worse.

The need is for people to act in community for the betterment of all, and that means paying the costs for benefits not built into the economic payback formula. Economic payback alone is and always will be short-sighted until all non-economic, social, and environmental costs also are fully accounted for.


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## Ashful (Mar 30, 2015)

jebatty said:


> This is quite rational on an individual decision making basis. But what if everyone in the world followed this practice: no mercury reductions, no reduction in sulfuric and nitric acid emissions, no reduction in particulate emissions, no decrease in CO2, etc. Coal would forever reign as king and health, quality of life, and the environment would degrade until we all and other living things, cockroaches excepted, live in squalor, disease, and worse.


Good thing we have you to save us from ourselves.  

China's carbon footprint is increasing 10x faster than we can ever hope to reduce ours.  Exercise in futility?


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## EatenByLimestone (Mar 30, 2015)

jebatty said:


> This is quite rational on an individual decision making basis. But what if everyone in the world followed this practice: no mercury reductions, no reduction in sulfuric and nitric acid emissions, no reduction in particulate emissions, no decrease in CO2, etc. Coal would forever reign as king and health, quality of life, and the environment would degrade until we all and other living things, cockroaches excepted, live in squalor, disease, and worse.
> 
> The need is for people to act in community for the betterment of all, and that means paying the costs for benefits not built into the economic payback formula. Economic payback alone is and always will be short-sighted until all non-economic, social, and environmental costs also are fully accounted for.




You are quite free to feel that way.  I won't knock it.  The trained biologist in me wont let me get warm and fuzzy over carbon dioxide.  I fully support your right to spend your money the way you want to though.


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## jebatty (Mar 30, 2015)

I see our agreement as being very broad. I too consider economic return, and i suspect that every thinking person, objectively or subjectively, does the same. And fortunately we enjoy the ability to have a range of outcomes.


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## Lake Girl (Mar 30, 2015)

DougA said:


> many are not lasting any longer than the old incandescents yet cost way more.


I have found this problem too.  The other issue I have is that they are horrible in outside lights in the middle of winter...


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## Lake Girl (Mar 30, 2015)

What recycle facilities do you have for the CFLs?  No program exists in my area...


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## DougA (Mar 30, 2015)

Lake Girl said:


> I have found this problem too. The other issue I have is that they are horrible in outside lights in the middle of winter...


Funny thing is, the CFLs I have outside seem to work fine in the winter. I moved some of them outside when I switched the inside ones for LEDs.  I was told they won't work in the cold but so far they're good. Who woulda known?



Lake Girl said:


> What recycle facilities do you have for the CFLs? No program exists in my area...


HD and Lowes used to but stopped.  There are a few other Cdn stores that will take them and there is a bin for them at the landfill site but you can't put them in the garbage.  I really thought it was bad PR for Lowes and HD to stop but I still shop there. I guess they knew most people wouldn't stop shopping.
In Ontario, you are supposed to be able to take them to Rona, Cdn. Tire and Ikea.  You may not have anything other than crappy tire within a day's drive of you.


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## brad wilton (Mar 30, 2015)

thats okay we'll have mercury poisoning to complain about in a few years


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## Grisu (Mar 30, 2015)

In our area they get disposed of together with other hazardous waste (paints, oil etc.). 


brad wilton said:


> thats okay we'll have mercury poisoning to complain about in a few years



Only broken CFLs release a miniscule amount of mercury. That amount is easily saved by the mercury not emitted through a coal fired power plant due to the energy savings: http://www.popularmechanics.com/home/reviews/a1733/4217864/ 
With the switch to LEDs that is an outdated discussion anyway. 



EatenByLimestone said:


> The trained biologist in me wont let me get warm and fuzzy over carbon dioxide.



I am a bit surprised to read that casual attitude from a trained biologist. Ever heard of Liebig's law? It has already been shown that higher atmospheric carbon dioxide concentrations are not necessarily beneficial for plants: http://www.nsf.gov/news/news_summ.jsp?cntn_id=123798
Not to mention that changes in precipitation due to climate change will severely disturb agriculture.


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## TradEddie (Mar 30, 2015)

> Try a few thousand years... fire, candles, and oil lamps, all similarly red color temps.
> 
> Old houses look odd when lit by CFL or LED. New houses are generally very ugly, so by association...
> 
> ...



I believe one factor that influences our perception of the color from LEDs is that generally we've chosen interior colors that looked pleasant under incandescent lights, and even the palette of choices available were based on incandescent bulbs. I think that the battle to get warmer color LEDs will fade as our paint choices evolve to look better under modern bulbs.

TE


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## BrotherBart (Mar 30, 2015)

Grisu said:


> Only broken CFLs release a miniscule amount of mercury.



Yeah but when they crap out they stink to high heaven. Experience with more than one dying here.


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## iamlucky13 (Mar 30, 2015)

The article doesn't say this will replace LED lights. The article says it is a better type of LED light.



DougA said:


> I'm anxious to get rid of all my CFLs.



I also was, based on the visibly better color quality of decent LED's. Then Philips told me to wait (well, that's not how they phrased it, but it's how I read it), because they'll be coming out with an LED this year that uses only about half the power of existing models. I'm still not convinced they actually will, but the CFL's in most of my fixtures are cheap to run in the meantime, and LED's are continuing to drop in price.



jebatty said:


> Just pulled one pin-tube and it says it uses 220ma, that's 26W and not 13W on a 120V house circuit.



Power labels are for peak power, not average power, which is what the efficiency figures use. Also, a lot of bulbs have a higher than average rated draw while warming up. From other independent sources I've seen that have measured power draw from CFL's, it's always been pretty close.


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## peakbagger (Mar 30, 2015)

I love LEDs for my cold house and colder garage. The CFLs wouldn't work at all in the garage and the ones in the house when it was cold took a couple of minutes to warm up. LEDs are instant.


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## EatenByLimestone (Mar 30, 2015)

Grisu said:


> In our area they get disposed of together with other hazardous waste (paints, oil etc.).
> 
> 
> Only broken CFLs release a miniscule amount of mercury. That amount is easily saved by the mercury not emitted through a coal fired power plant due to the energy savings: http://www.popularmechanics.com/home/reviews/a1733/4217864/
> ...




Never heard of the law, but am quite familiar with the concept, which can be put to good use in many disciplines.   I agree that co2 is often not the limiting factor in plant growth.  You only have to look as far as the rainforest to find a cause of the week where the soil is the limiting factor.  

I'm not going to get into climate change.  You have your beliefs and nothing I say or reference would sway it 1 way or another just know that politics and science rarely mix. When they try to, everything gets corrupted and it becomes hard to sort fact and fiction.


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## Grisu (Mar 30, 2015)

The science is actually quite clear and has been for 150 years (http://www.bbc.com/news/science-environment-15093234) but I agree that arguing against political beliefs has become hopeless. It still remains that we are currently burning up the actual wealth of humankind while leaving future generations a huge debt in form of water and air pollution, deserted landscapes, overflowing landfills etc. At some point we will realize that we have plenty of money, just not much what we can buy with it.


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## drz1050 (Mar 31, 2015)

Graphene bulbs ARE LED bulbs. They're just a different way of producing it.

I work in semiconductor processing. I have yet to buy any of the current crop of LED bulbs available... they're all using antiquated technology that will be obsolete in the near future. LEDs have been around for a long time, but only for small circuit switches, interlocks and whatnot... usually they've been red. The idea of using them for home lighting is relatively new, and there are currently a couple big players investigating new technologies and ways of producing them cheaper. It's really all about scale. Especially when compared to memory or processor chips, the current way of producing LEDs is ridiculously slow and expensive. Most of them are still made on 50 or 150mm wafers... the rest of the industry is already 2 generations ahead, running 300mm. (200mm was in between). 450mm tools are currently being tested... those are going to be a pain in the ass... but I digress. 
When flash memory was first being introduced, all chips were being plated with gold. This has since been replaced by aluminum, copper and a few other metals, all far cheaper than gold. As fabs ramp up, yield increases. As yield increases, costs per chip go way down.

TL; DR: Moore's Law... in just a few years, the cost of a LED bulb will be less than half of what it currently is, and performance will be better.


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## Ashful (Mar 31, 2015)

@drz1050, I'm a very big user of GaN HEMT transistors, which are of course made in many of the same foundries as your GaN LEDs.  I'm assuming the LEDs are still on 4" wafer due to being on SiC substrate?  Any plans to move GaN onto a cheaper substrate, such as Si, a'la Nitronex?  SiC will never be a very cheap wafer, compared to Si, even when scaled.

I never looked into the tech, but AND had white LEDs, which I used to use for lighting in robotic vision systems, back in the early 1990's.  They may have been GaN in sapphire, which is also how they made the early GaN HEMTs.  Talk about, "not cheap."  [emoji12]


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## brad wilton (Mar 31, 2015)

grisu,being sarcastic,doesn,t seem to come out in computer human beings  change when they get punched in the face human nature


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## iamlucky13 (Mar 31, 2015)

drz1050 said:


> Especially when compared to memory or processor chips, the current way of producing LEDs is ridiculously slow and expensive.



I'm not so sure about that. Even memory chips are priced in the ballpark of $1-10. Processor chips can exceed $100.

Bulk LED's sell for pennies. You can buy high power (1+ W) Cree LED's in moderate quantities from places like Digikey for as little as 50 cents each. The lamp manufacturers who are buying more than one real at a time should be getting even better pricing. An 800 lumen bulb takes 8-12 of them. There's some room for further cost reduction, but not a huge amount.

A significant part of their cost is related to the tiny drivers needed to convert effectively unlimited 110 VAC to a stable 3.3 VDC, current limited, and deal with the havoc most dimmers cause. Then there's the relatively complicated bulb bodies, and usually a non-trival amount of aluminum formed into a big heat sink that the design revolves around.

Increasing the efficacy may actually help more with cost than further reductions in the price of each LED chip. Get the heat down low enough and designers more or less stop designing their bulbs around dissipating it.

All things considered, I'd be a bit surprised if 60W-equivalent LED's ever get below $5 a bulb. They'll never reach the $0.50 a bulb price of incandescents, and probably not the $2/bulb price of CFL's. I'm really not worried about that, though. Even at $10 a bulb they're a good value.

My main interest is seeing color rendering and luminous efficacy go up. These two goals go well together, since increasing the CRI almost inherently means reducing the efficacy, so improving the latter reduces the incentive not to improve the former.

Also, another decade or so down the road, bulbs might become a minority product. With the lifespans these lights are potentially capable of, we might move towards the LED's being built in to the fixtures. I've already seen some office-style recessed troffers designed like that.


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## drz1050 (Apr 1, 2015)

Apologies, the foundry I work at now does not produce LEDs. I know a bit about the manufacturing of them, but do not have any first hand experience.
I currently work with ALD & PVD processes on 300mm silicon wafers.

The last I heard about changing substrates for LEDs, they were looking at GaN wafers and bare Si. Sapphire wafers are still out there in labs too. GaN wafers will have a similar cost to SiC, but the lattice construction is far better, and again, once they scale, costs will drop dramatically. They are still fighting some issues building LEDs on Si wafers, but it's coming along. 
Comparing completed processor chips to LEDs.. the two are not comparable at all. For one, in each processor chip there are thousands of transistors, diodes, capacitors and resistors. Node size is at 14nm now, with 10nm on the horizon. Each wafer goes through hundreds of processing steps through the fab, while LEDs only need to travel a fraction of that amount. Per component, LEDs are ridiculously expensive to make as of now.
Improving heat loss goes hand in hand with improving technology. Remember those old computers that needed to be stored in 60 deg rooms? Some server racks/ gaming computers still require cooling, but that's only because they're constantly being overclocked... if they were running at the same speed they used to run at, there'd be no issue at all. But while megahertz used to be considered fast, now terahertz is a thing. 

As the LEDs are improved, heat will go down. As heat goes down, packaging will become easier. Also, please don't compare bulk LEDs with home lighting LEDs. 
Once costs drop farther, it will become very attractive for lamp/ chandelier manufacturers to integrate them into their designs.


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## drz1050 (Apr 1, 2015)

As far as color, there is no such thing as a white LED. The white ones you know are either red, green & blue ones together, or a blue one covered with a phosphorous lens.


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## Ashful (Apr 1, 2015)

drz1050 said:


> The last I heard about changing substrates for LEDs, they were looking at GaN wafers and bare Si. Sapphire wafers are still out there in labs too. GaN wafers will have a similar cost to SiC, but the lattice construction is far better, and again, once they scale, costs will drop dramatically. They are still fighting some issues building LEDs on Si wafers, but it's coming along.


Just to clear up some mis-information here, before anyone runs with it.  There is no such thing as a GaN wafer, at least in my area of work.  GaN is an epitaxial layer applied to a wafer of Sapphire, SiC, or Si.  I'm sure other substrate materials exist, but these are the three used in my area of work.  I do not know anyone trying to make a GaN wafer.


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## drz1050 (Apr 1, 2015)

Bulk GaN wafers do exist. They are grown on sapphire, and then shaved off. 
Here's an article talking about costs: 
http://www.luxresearchinc.com/news-...ide-costs-fall-60-2020-leading-more-efficient


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## DougA (Apr 1, 2015)

drz1050 said:


> As far as color, there is no such thing as a white LED. The white ones you know are either red, green & blue ones together, or a blue one covered with a phosphorous lens.


If the end result is a perceived white light, then most people would call it a white LED, regardless of how it is made.  If the Nobel Committee calls it white LED, that's good enough for this forum. _"White LED lights emit a bright white light ... "_
http://www.nobelprize.org/nobel_prizes/physics/laureates/2014/press.html


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## iamlucky13 (Apr 1, 2015)

drz1050 said:


> Apologies, the foundry I work at now does not produce LEDs.



No need to apologize. I think this is a good discussion...and I can just imagine somebody wandering onto Hearth.com looking for info on wood burning and stumbling into a discussion of the difference between gallium-nitride wafers and gallium nitride coatings on semi-conductors. 

Your points are fair, although I still think that hints towards a long term price minimum in the ballpark of $5 per bulb.



DougA said:


> If the end result is a perceived white light, then most people would call it a white LED, regardless of how it is made. If the Nobel Committee calls it white LED, that's good enough for this forum. "White LED lights emit a bright white light ...



Strictly speaking, the Nobel prize was for the invention of the blue LED, but still, I see nothing misleading in the context of ordinary discussion with calling a phosphor coated or shrouded LED a white LED.


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## Ashful (Apr 1, 2015)

drz1050 said:


> Bulk GaN wafers do exist. They are grown on sapphire, and then shaved off.
> Here's an article talking about costs:
> http://www.luxresearchinc.com/news-...ide-costs-fall-60-2020-leading-more-efficient


Okay, yes, it does exist... in a completely non-commercial form.  Even your Lux Research article links to another stating GaN on GaN is a "non starter for now":

http://www.luxresearchinc.com/news-...efficient-gan-power-conversion-devices-hit-11

Again, I'm one of the larger GaN consumers in the country, being Cree's largest single customer on several of their devices.  I've not come across a commercial use of GaN on GaN, in my work.


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## begreen (Apr 5, 2015)

BrotherBart said:


> Yeah but when they crap out they stink to high heaven. Experience with more than one dying here.



We've gone through many CFL bulbs over the years, especially in the kitchen. Only one stunk. It was an original Philips CFL. The cheapy HomeDepot units I have had for the past 7 years have simply stopped working, no smell. We are fortunate that our local power company lets us drop off fluorescent bulbs at their office. Starting next month our county waste transfer station is also going to start recycling them.


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## Ashful (Apr 5, 2015)

begreen said:


> We are fortunate that our local power company lets us drop off fluorescent bulbs at their office. Starting next month our county waste transfer station is also going to start recycling them.


We still stick 'em in the trash here.  Fun getting rid of those old 8' T12's.  If there's a way to recycle them locally, most aren't aware of it.


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