# I don't think LED has a future



## Anders Hoveland (Apr 13, 2013)

I don't think LEDs have a future, at least not in their current form.
While LEDs are ideal for many applications, general lighting is not one of them. I know this post is probably going to enrage many members here, since this forum is filled with LED enthusiasts. Do not get me wrong, LED is great for traffic lights and flashlights.

If you think about it, white LED light is mostly just an orangish phosphor with a specific blue frquency thrown in. It's not _really_ white light.

No matter how enhanced white LEDs are, many people are still going to find them off because of that narrow deep blue frequency spike. The harshness of blue LED light is due to two things. First, the short wavelength, it is "hard" blue frequency light. This makes it appear a little purplish, but also makes it more difficult for the eye to focus on. In fact, the deep blue wavelength peak from white LEDs (465nm) is almost *indigo* (considered to start at 464 nm). The other problem is that the narrow concentration into a frequency spike makes it appear harsh rather than soft. Typically light sources are perceived as "softer" if they have a more smoothly distributed spectrum without any sharp spikes.

I think the reason we have not heard more complaints about the quality of LED light is simply the fact that so few consumers are actually using them. The people who have actually bought LED lighting for their homes at this time are probably not typical of the wider consumer base. Technology oriented people who just want the latest new technology in their home - typically men who are not too concerned about the quality of light, "environmentally conscious" consumers , most of whom were already using CFLs before they switched to LEDs, so they really have nothing to complain about in comparison. And most of the remainder are only using LED downlighting in their kitchens. This is not really the same as using LEDs in the rest of the house. Many people prefer "whiter" (more bluish) light in the kitchen, if you think about it, while many homes are using fluorescent lighting in their kitchen, few houses had fluorescent lighting anywhere else.

We will probably see LED replace more outdoor lighting applications, and be used more frequently in street lighting, but I do not think they are going to take over entirely. Some cities will switch to LED for the clean white colored light and low maintenance. But the fact is that many cities are discovering that LED street lighting is not all that it is claimed to be. It is can be more glareful to drivers (both because of the point-like light sources from a non-diffused LED array, and because of the deep blue frequency which is difficult to focus on) and often results in poorer useful illumination than the claimed equivalency ratings (the ambient light from the old streetlights contributes more to illumination than many realize, and the supposedly better scoptic index for blue LED can be misleading for fast moving objects). While many consider low pressure sodium to be ugly, it does at least have a warm glow without glare and is more comfortable to drive under. And besides, low pressure sodium has a similar efficiency to commercially available LED street lamps. While LEDs could be made with much lower CCT, I doubt this will be used for street lighting because of the sacrifice in efficiency. The latest technology of ceramic metal halide can offer higher CRI than standard LED.

But this post is not really about street lighting. I just do not think LEDs are really going to take over our homes. And I have doubts we will see LEDs replace fluorescent lighting in schools and offices any time soon.

I just think LED lighting is, in many ways, mostly just a big fad right now. LED technology has a long ways to go before it is ready for lighting our homes. As it is right now, the technology is essentially just a blue chip with orange phosphor. There needs to a new basic concept, and better phosphor compositions need to be developed. I especially think doped ZnS phosphors hold promise for more even frequency coverage in the blue part of the spectrum (or possibly blue halophosphate). 

The lighting industry and government seem to be spending a lot of resources pushing a technology that in many ways simply is not ready to replace everything. And I think we also need to get away from the idea that quality of light needs to be sacrificed for the sake of efficiency. When it comes to indoor lighting, if there is a phosphor that has a moderately lower efficiency but gives better spectrum coverage, it should be used.

LED is not the only potential technology. All the research is currently focused on LED because it is seen as the most efficient and promising, but there are other potential technologies being neglected, ESL, sulfur plasma, and hybrid light sources, for example. And I think students and office workers would benefit far more if more attention was given to natural lighting and light tubes. There are far more potential efficiency gains to be made from better architectural design than LED lighting. Smart motion detector systems could save more energy than LEDs in most situations (though fluorescent does not work so well with motion activation, for several reasons).


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## Statemachine (Apr 14, 2013)

Critical mass is almost there and the Chinese are quite enthusiastic about this technology.Apparently legislation is also aiding the led market in Europe?Those other technologies are just that right now.


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## LEDAdd1ct (Apr 14, 2013)

I thought for a moment before clicking "Reply," and I'll state my opinion.

Others, with a greater lexicon, more knowledge of the science and engineering behind LEDs as well as stronger emotions will also respond, no doubt.



Anders Hoveland said:


> I don't think LEDs have a future, at least not in their current form.
> While LEDs are ideal for many applications, general lighting is not one of them. I know this post is probably going to enrage many members here, since this forum is filled with LED enthusiasts.



First, if you are "enraged" by something you read on an online forum, you need to get off the computer, open your door, and greet the wonderful world outside that we are supposed to be using our lights in. I give you my word as someone with doings outside this 4:3 box that I am not enraged. 




Anders Hoveland said:


> No matter how enhanced white LEDs are, many people are still going to find them off because of that narrow deep blue frequency spike. The harshness of blue LED light...



Second, and I mean this in the most honest way, have you ever used a neutral, warm, or high-CRI LED, or are all your perceptions based upon long out of date Lux I and III emitters and the unfortunate tint lottery of yore? Look at any XR-E Q3 5A, XP-G2 R3 5A, 90+ high-CRI Nichia, high-CRI XM-L2, etc...If you live in the desert, take a flashlight with you there. If you dwell near the woods, take a flashlight with you there. If you live in the plains, go for a walk in a corn field. Go for a walk with one of those emitters, and tell me about how horribly blue and cold things look. 



Anders Hoveland said:


> I think the reason we have not heard more complaints about the quality of LED light is simply the fact that so few consumers are actually using them.



Who is the "we" and who is making the complaints? The average consumer looks at one thing, and one thing only: cost. I'm not really sure who you anticipate doing the complaining. The truth is, most people do not really care about the quality of light, they care only about the amount of coin they need to plunk down. 

As many people participate on this forum, most of us recognize we are in an extreme minority. For most people, lighting can be broken down into three "caring" categories:

Category One = Sticker Price

"How much do I pay now?"

Category Two = Total Cost of Ownership

"How much do I pay now, plus how much do I pay over the life of the consumer good?"

Category Three = Total Cost of Ownership + Aesthetics 

"How much do I pay now, plus how much do I pay over the life of the consumer good, plus how do I feel about the way it impacts my daily life, how does it perform, and how does it look?"

The vast majority of people fall into Category One.

A smaller segment falls into Category Two.

The vocal minority falls into Category Three.

I recognize that I am fortunate enough that after paying for food, gas, electricity, heat, clothing, toothpaste, deodorant (if I'm feeling generous), etc. I have the *luxury* of indulging in this hobby. 

Others, such as those in law enforcement, detailed engineering work, search and rescue, etc. are thrust into this world because their job requires it.

However, I argue that both people like me, those lucky enough to be able to afford to discuss these things and participate in this hobby,
and those who are involved in lighting because their job (or life) depends on it still comprise a very small percentage of those who require artificial illumination.

People like me (hobbyists) and people who _need_ light (professionals) fall into Category Two and Category Three.

The overwhelming majority of those on our planet, by a landslide, fit into Category One:

"How much do I pay now?"

In conclusion:

1) It is difficult to understand your perspective on "[the] narrow deep blue frequency spike" and "the harshness of blue LED light" in our post tint lottery world. You can go for a night hike with a tint as cool as you like, or a tint even warmer than an incandescent (which, as Lux Luthor will happily point out, come in many different CCTs and in varying degrees of light quality, from your lowly Mag 2xAA to a high temperature, overdriven hotdrive). 

Most people do not base purchases on spectrometers—their wallet is the sole deciding factor. 

2) If it is cheap, people will buy it. Those of us who are privileged enough to have the free time to post on CPF are in the minority, as are those professionals who need light of a certain tint, CRI, output, etc. Most people simply do not have the time or money (privilege) or need (profession) to care or desire _to_ care. 

I'll step back now. 

There are others, no doubt enraged, who will step in and voice their own opinions.


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## Tana (Apr 14, 2013)

I disagree with post #1...


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## uk_caver (Apr 14, 2013)

I'm not sure you're going to 'enrage' that_ many_ people, since many people will be aware of your past posts and, I suspect, will tend more towards '_meh_' than _'aaargh!_'.

New technology is always overhyped by some people, just as it is overcriticised by others, but to a large extent, it has its own momentum, independent of one or other extreme view.

It's not exactly an act of extreme prophecy to suggest that there isn't some imminent mass conversion likely to happen in existing schools and industrial buildings.
Not only is the general economic situation strained in many places, dampening the case for capital expenditure which may have a long-term payback, but with LEDs still meaningfully improving, it could be the case that in the long term, even if replacing fittings now would be expected to pay off compared to existing installations, given the expected efficiencies of predicted future fittings, the expected payoff for waiting a year or few may be greater.
And not only that, but a pretty confident short-term prediction could be made simply by looking at existing behaviour.

In what way is smart motion sensing vs. LEDs any kind of either/or situation?


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## AnAppleSnail (Apr 14, 2013)

+1 on the 'meh' reaction. Internet contrarianism used to bother me. I don't mind how many consumers do or don't use LED lights. They move on store shelves. I don't mind how people do or don't like them, because the workers at our factory like the LED high-bay units much more than the existing ones. Maintenance likes fewer trips over machines in lifts, too. I don't much mind what others think of the LED color rendering, because most people I talk to and work with find them adequate, not worth noting, or better.

Meh, because you still repeat minor quibbles. My fluorescent lights and LEDs both show blues and navys better than filaments or many arc-lamps. Human vision adjusts.


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## sidecross (Apr 14, 2013)

I like this title and post and I thank you for the time you took to write it. :thumbsup:


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## thedoc007 (Apr 14, 2013)

Anders, let me be the first to congratulate you on a well thought-out post. While LEDAddict does make good points, especially about warmer tints, I did find your post interesting, and I appreciate you taking the time to consider other technologies that also offer promise. I agree that we should not focus exclusively on LED lighting, at the expense of stagnating other technologies that might offer similar potential in certain areas.

Well, maybe not the first...I need to work on my typing speed.


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## Steve K (Apr 14, 2013)

I have to admit.. I saw the thread's title, saw that Ander's wrote it, read the first paragraph or so, and just said "oh.. another rant from Anders about how LEDs are the end of civilization...". After perusing the rest, I feel reassured that my instinct was correct.


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## uk_caver (Apr 14, 2013)

thedoc007 said:


> I agree that we should not focus exclusively on LED lighting, at the expense of stagnating other technologies that might offer similar potential in certain areas.


I doubt many people _would _suggest that 'we' (as in 'humanity') should focus exclusively on any technology, and I think that'd still generally hold even if looking at people more than typically enthusiastic about one particular technology.

However 'we' (as in 'us here'), excluding those of us who may be actually involved in lighting research, will likely largely focus on what is currently available or likely-soon-available, since we're mainly concerned with the practical end use of technology.

Some other tech _might_ be around in 5 or 10 or 20 years giving better performance than LEDs?
Great - I'm sure I'll see it mentioned in the news when it is nearing production.


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## SemiMan (Apr 14, 2013)

thedoc007, 

Anders post is not well thought out at all. In fact he mimics parts of posts that other who actually know lighting and know that LED will take over use to discuss real lighting topics (i.e. about the lack of advantage at high speed of scotopic/mesopic lighting). 

Anders has very limited knowledge of lighting, lighting science, optical science, human vision and certainly diddly squat w.r.t. the lighting industry.


- Anders keep making this dumb posts repeatedly about a non existant whole in the spectrum in the blue / green. If you compare to a 3000K halogen bulb, there is actually less at the spectrum. It is easy to make very high CRI, 95+ LED sources with almost no blue spike near perfect color and to do it across the CCT spectrum. However, that is not what the market for the most part is demanding and hence why is it not being done on mass. However, specialists like Xicato, the Bridgelux Artist series, some of the Sharp Zenigata LED models, Soraa, etc. are doing just this. They give up significant efficiency w.r.t. other LEDs thougth and hence the market demand at this point is low and hence costs are higher. As LED efficiency improves and costs come down, there share will grown.

- LPS is virtually unused these days. While initial lumens/watt is high, the efficiency RAPIDLY degrades AND the huge relative source size makes optical control very difficult hence you effectively light the neighbourhood, not the street

- Glare is an issue and is being addressed both with a movement to lower CCT which impacts the relative amount of blue, and also by better optical designs. A well designed 4000K streetlight has little glare in urban/residential settings. I know, I drive under a lot. Actually even at 5000K (having designed one or two), a tight optical control, i.e. llittle/no light beyond 60 degrees, yields very little in the way of effective glare in most situations unless you feel inclined to look right at the light which few do. Most LED streetlights are arrays of LEDs and hence the source size is effectively large. Even if a single or several large LEDs are used, the source brightness is no higher than metal halide which lights many a parking lot. Last generation LED technology was competitive with HPS for streelights due to high placement accuracy (light where you want). This gen of LEDs both in cost and efficiency makes it an easy decision.

- CMH "can" have higher CRI than LED, however, especially for retail, the efficiency at the fixture level is "okay" and the costs is actually quite high. 15-20000 hour (maybe), bulb cost more than equivalent LEDs and are seen by those high CRI LED mfrs as the low hanging fruit.

- I don't know a single customer with MR16s or GU10s who would not in a second replace them with a good quality alternative. Many have a ton of them and they cost a fortune to run. Watch for en-mass replacement over the next few years.

- Interior metal halide high and low bay lighting is again low hanging fruit. Almost impossible to justify a new install with them when LED maintenance costs are so much less and efficiency is better at equal/better light efficiency.

- Oh, white LEDs are typically at 455nm, not 465 as 455 makes a better pump

- Did you know without <500nm light and a good amount of it, your body thinks it is night. Not good for the vast amount of interior daylighting that is used. Blue is not bad .... we have it all the time in sunlight. 

- Did you also know you need those short wavelengths, under 500nm in order to properly regulate your iris? It is true that it is harder to focus across a wide range of wavelengths. However, in most interior lighting conditions, removing short wavelengths creates far worse focussing issues. Anyone with a basic understanding of depth of field knows this. We can filter out blue in sunlight because there is so much of it and our iris is already closed up. Under articial sources of light, lack of blue causes the iris to be too wide drastically reducing depth of field which causes significant eye strain as the eye must constantly adjust focus significantly to maintain focus

- ESL is neglected because it SUCKS! ... 30 lumens/watt, 10000 hours, not meeting light quality claims

- Plasmas is not being ignored, it just has known efficiency targets that LED blows away, has limited CCT color range (5000Kish) ... so you not see it in a house, and the claims on efficiency are not even really being met

- Hybrids sources are not being investigated as they do not make sense. Optically mixing sources of the same optical properties is difficult. When you have different optical properties (size, emission pattern, etc.) as well as different lumen maintenance, failure modes, power supply requirements ... it is obvious to product designers to be a dead end w.r.t. cost, efficiency, etc.

- OLED is getting a ton money for research.

People with infinitely more technology and market knowledge decide where to invest ... based on sound research, not supposition. If other technology is not being invested in, there is a bloody good reason for it!

There is more attention being paid to architectural design, natural lighting, daylighting, etc. but that is mainly only possible in new builds as it is prohibitively expensive to retrofit. Light sensors to automatically adjust artificial lighting coupled with natural ligthing is a big trend. For streetlighting, advanced controls are also being put in place. In many jurisdictions that have energy incentives, the incentives for savings are the same no matter the source.

At all the lighting shows around the world, LED dominates. To think it does not have a future is ignorant.

Anders your comments are just ignorant based on your own psychological issues w.r.t. anything not incan/halogen coupled with issues with any government programs. If you want to bring value here, put away the bias, learn something, and try to move forward.

Semiman


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## sidecross (Apr 14, 2013)

Semiman

Thank you for your comment; I am in the 'dark' on the science you have addressed.

Your word of caution is appreciated. :thumbsup:


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## Arm and Leg (Apr 14, 2013)

Wow, I think you're stuck in 2001 mate.

Four words, Nichia-Two-One-Nine


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## bose301s (Apr 14, 2013)

Thank you SemiMan, you hit the nail on the head. Except the part about white LEDs using 455nm as a base, I can assure you that a wide range of wavelengths are used and teh choice of base blue wavelength is dictated by what CCT you are looking to achieve.


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## Esko (Apr 14, 2013)

Anders Hoveland said:


> I don't think LEDs have a future, at least not in their current form.
> While LEDs are ideal for many applications, general lighting is not one of them.
> ...
> No matter how enhanced white LEDs are, many people are still going to find them off because of that narrow deep blue frequency spike.



Ambient home lighting is usually around 3000K. If you check some emission curves (just google "warm led spectrum"), you can see that the blue spike is rather tiny and low.




Anders Hoveland said:


> There are far more potential efficiency gains to be made from better architectural design than LED lighting. Smart motion detector systems could save more energy than LEDs in most situations (though fluorescent does not work so well with motion activation, for several reasons).


And leds make it a lot easier to accomplish.

I believe that leds have a bright future in lighting the world.

Of course, in 5-30 years we might see another better techonology that eventually replaces them, too.


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## degarb (Apr 14, 2013)

Anders, you are totally correct. And you know, if you think about it, there are other fads too: like, the Internet (how long before we get bored with it?), CRT television sets (now using whizbang, fad "leds"), those stupid smart phones (the batteries never keep up), and even cars! (Aren't you tired too, of buying new batteries, tires, bulbs, and insurance?)

The fact that Edison's bulb was just a short lived fad, moreover, proves your point! If he couldn't get a technology to REALLY stick, certainly this whole LED thing will pass!


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## IMSabbel (Apr 14, 2013)

Another troll thread by Anders.

Nobody should waste arguments on this guy. He is just getting off of the controversy. As an example, in a previous thread, 50+ posts were unsuccessful in explaining to him what a lumen is, as that explanation would have countered his inane arguments.


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## RoGuE_StreaK (Apr 14, 2013)

Steve K said:


> I have to admit.. I saw the thread's title, saw that Ander's wrote it, read the first paragraph or so, and just said "oh.. another rant from Anders about how LEDs are the end of civilization...". After perusing the rest, I feel reassured that my instinct was correct.


:laughing: I actually LOLd a little at this one 

That said, I do agree with the sentiment of using/piping natural light where possible. Doesn't have anything to do with LED not having a future, but it's a good philosophy.

To paraphrase what's been said by others, we're end users aiming to use the best/most efficient readily commercially available (within cost boundaries); somehow I don't think research has stopped on other technologies, or LED technologies for that matter. Researchers don't make a name for themselves by doing minor tweaks of existing technology.


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## degarb (Apr 14, 2013)

RoGuE_StreaK said:


> :laughing: I actually LOLd a little at this one
> 
> That said, I do agree with the sentiment of using/piping natural light where possible. Doesn't have anything to do with LED not having a future, but it's a good philosophy.
> 
> To paraphrase what's been said by others, we're end users aiming to use the best/most efficient readily commercially available (within cost boundaries); somehow I don't think research has stopped on other technologies, or LED technologies for that matter. Researchers don't make a name for themselves by doing minor tweaks of existing technology.




Since, this topic doesn't specifically deal with a practical led application, it really is a "what if" post, and a cafe topic.

I think we need to all chip in and buy Anders some good led lights. Maybe he is earnest, and just not the pocketbook to try good leds. 
I can see his angle if you owned a lamps shop, where the beauty will lag behind the led technology--though, I have no doubt bulb beauty will come shortly. Actually, leds are more flexible, and more potential for a more varied artist design than anything achieved with incan.


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## mvyrmnd (Apr 14, 2013)

Steve K said:


> I have to admit.. I saw the thread's title, saw that Ander's wrote it, read the first paragraph or so, and just said "oh.. another rant from Anders about how LEDs are the end of civilization...". After perusing the rest, I feel reassured that my instinct was correct.



I'm glad I was not the only one.


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## RoGuE_StreaK (Apr 14, 2013)

degarb said:


> more potential for a more varied artist design than anything achieved with incan.


I think an issue is that LED bulbs (and CFL) are having to be designed to retrofit existing fixtures, which require the bulb to look and act like a traditional incan; if you were designing an LED lighting solution purely from scratch, you'd do it completely different.


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## SemiMan (Apr 15, 2013)

bose301s said:


> Thank you SemiMan, you hit the nail on the head. Except the part about white LEDs using 455nm as a base, I can assure you that a wide range of wavelengths are used and teh choice of base blue wavelength is dictated by what CCT you are looking to achieve.




Hey bose301s, thank you for replying. I think you said you work in process at Cree?

I know in the past, at least with Lumileds, the target for the blue pump LEDs was 455 as that was the efficiency peak for energy transfer with the YAG phosphors. I am aware that CCT changes with the blue pump, but that can be played around with by phosphor pump ratios as well that would dominate to some degree. I have not researched in a while how that may impact CCT/CRI though. 

Semiman


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## SemiMan (Apr 15, 2013)

"The global LED lighting market will be worth $25.4B in 2013, representing 54% growth on the 2012 result of $16.5B, while the LED lighting penetration rate will also rise to 19%, according to a new DIGITIMES Research Special Report. "

Kinda says it all doesn't it?

Semiman


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## AnAppleSnail (Apr 15, 2013)

SemiMan said:


> Kinda says it all doesn't it?
> 
> Semiman



No. I don't have figures on the global lighting market in general. The closest I can find is 100 billion Euros for general lighting in 2020.


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## slebans (Apr 15, 2013)

AnAppleSnail said:


> No. I don't have figures on the global lighting market in general. The closest I can find is 100 billion Euros for general lighting in 2020.



I read a lot of reports in this area. They are all estimates so it is difficult to know which report are accurate. A lot of government reports reference this data:
http://www.mckinsey.com/~/media/mck...spectives_on_global_lighting_market_2012.ashx


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## dparr (Apr 15, 2013)

I'm a caver!

Thank goodness for LED's.


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## bshanahan14rulz (Apr 15, 2013)

As long as nobody pulls that line about not agreeing with what someone says, but defending their right to say it or something. I hate that line....

But yeah, it may not fit YOUR needs, but it fits many many other peoples' needs. LEDs are here to stay, for quite a while, in one form or another.


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## bose301s (Apr 15, 2013)

SemiMan said:


> Hey bose301s, thank you for replying. I think you said you work in process at Cree?
> 
> I know in the past, at least with Lumileds, the target for the blue pump LEDs was 455 as that was the efficiency peak for energy transfer with the YAG phosphors. I am aware that CCT changes with the blue pump, but that can be played around with by phosphor pump ratios as well that would dominate to some degree. I have not researched in a while how that may impact CCT/CRI though.
> 
> Semiman


Yes, I work in Nitride Epi so I don't see any of the back end processes or phosphor work etc. but I do see what WL of LEDs we are growing and targeting and I will say that it is all over the map, lol.


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## SemiMan (Apr 15, 2013)

I GOT IT, I GOT IT, I GOT IT ....

I now know the reason for this thread. The actual title is wrong and was longer than originally planned. I was just supposed to be:

"I don't think" ......


And with that I will apologize to my fellow CPFers, but you have to know I have been holding it in for over 24 hours ... the genie had to be let out.

Semiman


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## uk_caver (Apr 15, 2013)

Or could just be failed punctuation.

I don't think.
LED has a future.


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## Empath (Apr 15, 2013)

Anders Hoveland said:


> I know this post is probably going to enrage many members here, since this forum is filled with LED enthusiasts.



In light of CPF's rule 4, and your admission above as to its violation, let's close this baiting and trolling thread. It's a shame, really; since the OP has some intelligent and legitimate concerns about LEDs. Such concerns could well be discussed to everyone's benefit, in a non-baiting and non-trolling manner. Perhaps it's something you'd like to keep in mind, should you decide to discuss it again.

Closed.


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