ESL bulbs?

PhotonWrangler

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Ran across this today on Gizmodo. A company calling themselves Vu says they're launching a "new" lighting technology that uses "accelerated electrons" to light up a phosphor coating. Kind of sounds like those Genura lamps from G-E. At 40 lumens per watt and a 6000 hour life, I think they've got a ways to go before they have something viable. What do you think?
 
Funny to think of this as "new". The cathode-ray tube has been around for 100 years...

Buy yourself a EM80 or EM84 electron-ray indicator tube if you want to play with "accelerated electrons to light up a phosphor coating".
 
vu1_bulb.jpg


The technology is basically the same as the old cathode-ray televission tubes. Right now there is only one version of this new bulb available, a directional 65-Watt equivalent. It is only being sold by one home improvement store chain in the USA at this time. The price is 15 dollars each.
The quality of light from this new bulb is claimed to be better than that from both fluorescent and common white LED's, although still not quite as good as halogen incandescents. Here is the spectrum:

Spectrum_ESL.jpg



As this is a very new product, I cannot find any information about whether ESL bulbs give off some UV radiation like CFL's do, or whether they would be suitable for certain people with skin sensitivity issues. I also wonder whether or not there might be some slight X-ray radiation, since it is after all the same technology as the old cathode ray televissions. Remember parents warning children not to sit too close to the TV ?
 
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vu1_bulb.jpg

The technology is basically the same as the old cathode-ray televission tubes.
As this is a very new product, I cannot find any information about whether ESL bulbs give off some UV radiation like CFL's do, or whether they would be suitable for certain people with skin sensitivity issues.

I also wonder whether or not there might be some slight X-ray radiation, since it is after all the same technology as the old cathode ray televissions. Remember parents warning children not to sit too close to the TV ?


Good point about the EMF. Back when computer monitors were all CRT's, we used to measure the EMF from them. For monitors at least, MOST of the EMF emission was at the REAR of the monitor, not radiating/projected from the screen....even though std measurement protocols dictated measurements from the screen to the seated victim. In reality, exposures were typically worse for those seated at adjoining work stations, close to the BACKS of adjacent monitors, etc.
 
I would not think these ESL bulbs would emit any more EMF (radiofrequency energy) than CFL's, as both have ballasts.
The output in the base of a CFL ballast is typically 600 volts, whereas the tubes in these EML bulbs use 5000 volts. But then again, higher voltage at the same power means less current, and less EMF.

The EMF given off by the common energy saving CFL's is still a concern to some. There is plenty of controversy about the possible links between EMF and health problems, whether this EMF comes from power lines or cell phones. (while LED replacement bulbs also contain a transformer, their EMF emissions are insignificant when compared to CFL's)

As for X-rays, if there are any, they would be very "soft", since the tube operates at only 5000 volts, so nearly all of the X-ray radiation would be absorbed by the thick glass. Although the glass in this company's ESL bulb is not leaded glass, as it was in most TV/computer cathode ray tubes. One of the major selling points of the ESL bulbs are that it does not contain any mercury, and so its improper disposal does not create an environmental hazard. Using leaded glass would not exactly be the most environmentally friendly. It would sort of just be substituting one heavy metal for another.

The concern for me would be possible UV radiation. I would think these ESL bulbs would give off much less than CFL bulbs. CFL's essentially use mercury vapor to first make UV light that then excites the phosphor coating. So obviously there is a high potential for UV to leak out. In contrast, ESL bulbs use accelerated electrons in a vacuum to excite the phosphor coating. UV radiation from these CFL's can cause skin irritation and reddening even in people without any known sensitivity to UV light. It can also cause furniture and paintings to fade over time. If you look at the plastic base of an old CFL, you can often see that the white plastic has become yellowed from the UV.
 
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Yeah, but if you can accelerate the electrons fast enough you could theoretically reply to PhotonWrangler back when this thread was originally created.

:thumbsup:
 
Yeah, I am surprised these ESL bulbs are still not available, even after four and a half years. The company produced a few of them, but they sold out really quickly, and the company has not been ready to sell a new supply for the last six months. I hope the ESL technology has not entered the market too late. While ESL's have their own unique advantages, it is really sort of a specialty niche. The CFL technology has already been more developed, and LED's have already come into mass production. The ESL's may be squeezed out of the market by the other available technologies, since they were developed first.

The problem is that these first ESL bulbs consume just slightly more power than CFL's. If someone wants "efficiency", they are more likely to go with CFL's, where as if someone wants quality of light they are more likely to go with incandescent bulbs. Few people will be willing to pay more for bulbs that are almost as efficient as CFL and have almost the good quality of light as incandescents, especially when LED's are available that are both much more efficient and have a quality of light somewhere between CFL's and ESL's. Although, like I mentioned, ESL's do not cost much more than dimmable CFL's, so if ESL's make sense anywhere, they would best replace dimmable CFL floodlights. The problem is most consumers do not think about all the subtle advantages and disadvantages of lighting, and are unaware what the optimal choices are for each particular situation. From what I have seen, most people do not like to think very much when buying light bulbs. The vast array of different lighting options now available has mostly resulted in consumer confusion. Most consumers only care about two things: initial price and light output. That is, until they get home and realise they are not happy with the new lights.

Here is a review of the ESL bulb:
Vu1 recently sent me its R-30 type light bulb — the type used in recessed lighting fixtures — to evaluate. Although still a test unit, the bulb was close to being a final product; the one I tried is slightly longer than the final version. The bulb had its pros and its cons. On the bright side, the light was very much like an incandescent (as promised), with the warmth I miss in whiter bulbs. There was none of the annoying vibration (or "flicker") that I sometimes sense with fluorescent lights. And unlike many fluorescents, the bulb was fully dimmable.
http://www.onlinebuyreview.com/esl-lightbulbs-diy-product-review/
 
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ESL got off to a slow start and its efficiency envelope is below CFL - itself not the most efficient tech. Their only real strength seems to be their potential to hit any color-rendition / temperature point the market could want, which has pretty narrow appeal.

I also suspect they lost out on the business-continuity/process/.gov incentive/goodwill end with their decision to move production from an old CRT factory in Eastern Europe (Czech Republic, I believe) to China.

As for low noise/EMI - a CRT needs high-frequency and high-voltage electronics to drive it last I checked. If these can pull off the same levels of noise as a cheap CFL I'd be amazed.



Light bulb purchases are pretty low-involvement for most consumers. The average buyer might vaguely remember a brand, a wattage, and a bulb style when presented with the light bulb section. They look up and down it a few times, settle on a general product, then hesitantly make their selection - all this seems to take about 30 seconds. The availability of CFL's and LED in Edison socket formats only confuses them ... I've seen Home Depot station people near the light bulb aisle to nudge them towards their house brand CFL's (more margin for Home Depot) only to be rebuffed with "I just want a light bulb" as they wander further down the aisle to pick up the familiar GE SoftWhite they originally wanted - and will complain bitterly about the cost of acquiring anything other than the cheapeast incandescents. Even buyers that specifically want a CFL don't much read the labels or make comparisons - they just seem to go with the familiar. I've yet to witness anyone else buy a LED bulb other than myself. It's really a purchase that most seem to think about only as long as they have to:
1. I need a light bulb for the (vanity/closet/hallway/guest bedroom/etc)
2. Pick one from the ever-changing light bulb aisle - more often, pick up a dozen or more
3. Replace the blown bulb
4. Forget about it
5. Some time later when another bulb fails and the utility-room stockpile has run down, loop back to 1
 
Again, I want to emphasise the ESL's are still the best choice of technology in certain very specific situations.

1. If you want increased efficiency but still want a quality of light better than CFL's or current LED's

2. If you want more efficient lighting, the UV radiation from CFL's is a concern, but you do not want to pay the higher initial price for LED's
(or perhaps you are concerned that someone may steal the more expensive LED)

3. If you are one of those people that are irrationally obsessed with the environment and do not want to buy an energy efficient bulb that contains mercury, but you need a retrofit bulb that can go into an enclosed fixture and are concerned about the higher power LED not functioning well because of overheating.
 
Again, I want to emphasise the ESL's are still the best choice of technology in certain very specific situations.

1. If you want increased efficiency but still want a quality of light better than CFL's or current LED's

2. If you want more efficient lighting, the UV radiation from CFL's is a concern, but you do not want to pay the higher initial price for LED's
(or perhaps you are concerned that someone may steal the more expensive LED)

3. If you are one of those people that are irrationally obsessed with the environment and do not want to buy an energy efficient bulb that contains mercury, but you need a retrofit bulb that can go into an enclosed fixture and are concerned about the higher power LED not functioning well because of overheating.


These are 500 lumens. That would not be high powered. About all these have going for them is initial cost. You can get Cree downlights for $30-35 with better specifications and 3.5 times the life. Over the life of the product, they will be cheaper. They also use 1/2 the power of the Vu1. Light quality will be every bit as good as the Vu1 which is also phosphor based.

So why are the three "reviews" on the Vu1 website all dated March 27? One claims the color is virtually indistinguishable from the other "standard" 65 watt bulbs. I find that hard to believe when the standard bulb is 2700K, halogen is 3,000 and the Vu1 is 3200. Everyone can see the difference from 2700 to 3000 and a good portion from 3000 to 3200.

Of course I would be more concerned that sales went from $7,000 in sales in the 6 months ended june 2011, and $0 sales in the six months ended june 2012. I think that pretty much means that customers are voting with their wallets. I have a feeling the cost to manufacture is such that retailers have no interest carrying them as there is no margin it for them. Hence the ability to buy direct on their web-site ...... which no one seems to be doing ......

At the end of the day, it is barely over 25 lumens/watt. It is a dead technology. It is easy to make high CRI LEDS with terribly efficiency, but that is not what the market wants any more than they want this bulb.

Semiman
 
Of course I would be more concerned that sales went from $7,000 in sales in the 6 months ended june 2011, and $0 sales in the six months ended june 2012. I think that pretty much means that customers are voting with their wallets. I have a feeling the cost to manufacture is such that retailers have no interest carrying them as there is no margin it for them. Hence the ability to buy direct on their web-site ...... which no one seems to be doing ......

At the end of the day, it is barely over 25 lumens/watt. It is a dead technology. It is easy to make high CRI LEDS with terribly efficiency, but that is not what the market wants any more than they want this bulb.

The original shipment to Lowes consisted of less than 1000 bulbs. They sold out quickly with the majority of bulbs purchased by shareholders of the then penny stock, VU1. These people then proceeded to post glowing reviews wherever they could in order to boost Vu1's image and hopefully the share price. Bulbs have not been available since this initial shipment.

Gradually, user began to comment on the green hue of the bulb's output and a high failure rate. Shareholders initially tried to downplay these reviews but eventually accepted them as truth and blamed it on the hand produced manufacturing process of their Sendio facility.
This facility was placed into bankruptcy and manufacturing was moved to China. Shareholders/users are still waiting for the first bulbs to be produced from China and shipped to Lowes.

I agree that the company and their product is dead in the water. Even if by some miracle they manage to produce and ship bulbs from their contracted Chinese manufacturer, Vu1 has severe financial problems that are not easily rectified - they've dug themselves a very deep hole to craw out of.
 
The original shipment to Lowes consisted of less than 1000 bulbs. They sold out quickly with the majority of bulbs purchased by shareholders of the then penny stock, VU1. These people then proceeded to post glowing reviews wherever they could in order to boost Vu1's image and hopefully the share price. Bulbs have not been available since this initial shipment.

Gradually, user began to comment on the green hue of the bulb's output and a high failure rate. Shareholders initially tried to downplay these reviews but eventually accepted them as truth and blamed it on the hand produced manufacturing process of their Sendio facility.
This facility was placed into bankruptcy and manufacturing was moved to China. Shareholders/users are still waiting for the first bulbs to be produced from China and shipped to Lowes.

I agree that the company and their product is dead in the water. Even if by some miracle they manage to produce and ship bulbs from their contracted Chinese manufacturer, Vu1 has severe financial problems that are not easily rectified - they've dug themselves a very deep hole to craw out of.


Wasn't that manufacturing transfer starting early spring or before? Green hue either tells me they don't have the phosphor mix correct or there is an inherent phosphor issue. That does not sound like 90 CRI :) Anders likes to spout off about things he knows nothing about and he is the only one promoting it. I should ignore it, but the less knowledgable may take what he says as fact and make bad decisions.

Semiman
 
These are 500 lumens.
Yes, that is the biggest disadvantage right now, only one type of version of this new technology is available (and whether it even is "available" is questionable right now). Hopefully we will see in the future ESL's that have more power, and are not just directional. But perhaps ESL's are best suited for directional lighting (particularly recessed lighting). Whether it is feasible to make omni-directional ESL's could be the topic for another long discussion. I think it certainly is possible, but the people building these things have much more experience with cathode ray TV tubes (directional). And then I wonder how much space an omni-directional ESL would take up. Might only be suitable for large globe lights, but this might not be so bad. After all, several ceilling fixtures throughout my house are basically just little bulbs inside a glass globe to diffuse the light.

And also remember that these "500 lumen" bulbs suppossedly do a better job of illumination than the lumen rating alone would suggest (not sure if that means it actually has a higher light output, or whether the light it does output is just optimally distributed), this has been noted in several online reviews by different people. This is just the opposite of LED bulbs, which seem to have higher lumen rating than their actual illumination would suggest (although this might not be the case in recessed LED fixtures, perhaps someone who has actually done a comparison can comment? )

About all these have going for them is initial cost. You can get Cree downlights for $30-35 with better specifications and 3.5 times the life. Over the life of the product, they will be cheaper.
This is not how the consumer thinks. You can argue that LED lights will save money in the long term all you want, but the vast majority of consumers will not care to understand or listen. Like idleprocess mentioned, consumers don't like to be made to think too much. If there are two "energy saving" products on the shelves, most consumers will just grab the cheaper one. ESL's could have an advantage in the actual marketplace. Even for people like us who know better, perhaps some of us just do not feel we can afford to buy all at once 12 recessed LED lights for a room.

And these ESL's would probably cost significantly less if they were being mass produced like the Cree LED downlights.

Another point that you neglected is potential theft. As a greater number of people buy expensive LED lighting, it is quite within the realm of reason that these lights could begin to become the target of theft. A less expensive bulb (even one that does not last as long or save as much money) might make more sense in high crime neighborhoods or outside locations. So what other options for these people who want to use energy efficient lighting but absolutely hate CFL's ?


Light quality will be every bit as good as the Vu1 which is also phosphor based.
That is just your opinion. Suppossedly these ESL bulbs have a better quality of light than LED's, and this would seem to be confirmed by looking at the spectrum graphs. Apparently better phosphors can be used when the excitation source is an electron beam rather than the UV from the mercury vapor in a CFL. Which reminds me, the fact that ESL's do not contain mercury is a big selling point to some of the consumers who are obsessed about the environment. There is a big clear label on the packaging that advertises it is "mercury free". Many consumers are going to think of this as a CFL-replacement that does not contain toxic mercury. And some parents are concerned about using CFL bulbs in homes with children.

This is probably a stretch, but we should not forget some people live in violent abusive households, with a certain family member who frequently knocks over and breaks lamps throughout the house (I have seen this first hand when I lived with another family for several months). Probably CFL bulbs may not be the wisest choice for such a family.

One claims the color is virtually indistinguishable from the other "standard" 65 watt bulbs. I find that hard to believe when the standard bulb is 2700K, halogen is 3,000 and the Vu1 is 3200. Everyone can see the difference from 2700 to 3000 and a good portion from 3000 to 3200..
Like I stated previously, there is much more to quality of light than just "color temperature". I tried a 2700K "warm white" LED and was not really happy with its light. Two light sources can be a different color but still have the same color temperature, so many people seem no to know that fact. In fact, color temperature is really rather inappropriate to describe light sources which are not black body radiators. In the current lighting marketplace, however, color temperature seems to be taken to mean how blueish the light is apparently. But this is not technically really color temperature. Regardless of color temperature, the current warm white LED light needs to be just a little more greenish (preferrably accomplished by adding blue-green frequency light, because paradoxically these LED's already have plenty of green frequency light, and while it would give the light a whiter color it would not help with CRI)


It is easy to make high CRI LEDS with terribly efficiency, but that is not what the market wants any more than they want this bulb.
I have been wondering why no really true full spectrum LED's have been made available. You may have a point, though we will have to wait and see. I think high CRI LED's might have demand in office lighting (hopefully), but then again most offices now do not even use "full spectrum" fluorescent tubes, so perhaps people do not care (or do not know). And in many cases, it is not actually the office renters themselves that are buying their lights, so there may be a lack of direct incentive to make good aesthetic choices. With more marketing and consumer awareness, there would likely be more demand for higher CRI lighting.

I read that when this company first began taking order for these ESL bulbs through their site, they sold out within only 2 hours!
Apparently the media coverage online had caused several environmental blogs to write about, which generated considerable interest before it was even available. So while this ESL bulb might not really have a broader appeal, it certainly is being enthusiastically embraced by a small subgroup of consumers. There is a strong niche market.
 
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Yes, that is the biggest disadvantage right now, only one type of version of this new technology is available (and whether it even is "available" is questionable right now). Hopefully we will see in the future ESL's that have more power, and are not just directional. But perhaps ESL's are best suited for directional lighting (particularly recessed lighting). Whether it is feasible to make omni-directional ESL's could be the topic for another long discussion. I think it certainly is possible, but the people building these things have much more experience with cathode ray TV tubes (directional). And then I wonder how much space an omni-directional ESL would take up. Might only be suitable for large globe lights, but this might not be so bad. After all, several ceilling fixtures throughout my house are basically just little bulbs inside a glass globe to diffuse the light.

And also remember that these "500 lumen" bulbs suppossedly do a better job of illumination than the lumen rating alone would suggest (not sure if that means it actually has a higher light output, or whether the light it does output is just optimally distributed), this has been noted in several online reviews by different people. This is just the opposite of LED bulbs, which seem to have higher lumen rating than their actual illumination would suggest (although this might not be the case in recessed LED fixtures, perhaps someone who has actually done a comparison can comment? )


This is not how the consumer thinks. You can argue that LED lights will save money in the long term all you want, but the vast majority of consumers will not care to understand or listen. Like idleprocess mentioned, consumers don't like to be made to think too much. If there are two "energy saving" products on the shelves, most consumers will just grab the cheaper one. ESL's could have an advantage in the actual marketplace. Even for people like us who know better, perhaps some of us just do not feel we can afford to buy all at once 12 recessed LED lights for a room.

And these ESL's would probably cost significantly less if they were being mass produced like the Cree LED downlights.

Another point that you neglected is potential theft. As a greater number of people buy expensive LED lighting, it is quite within the realm of reason that these lights could begin to become the target of theft. A less expensive bulb (even one that does not last as long or save as much money) might make more sense in high crime neighborhoods or outside locations. So what other options for these people who want to use energy efficient lighting but absolutely hate CFL's ?



That is just your opinion. Suppossedly these ESL bulbs have a better quality of light than LED's, and this would seem to be confirmed by looking at the spectrum graphs. Apparently better phosphors can be used when the excitation source is an electron beam rather than the UV from the mercury vapor in a CFL. Which reminds me, the fact that ESL's do not contain mercury is a big selling point to some of the consumers who are obsessed about the environment. There is a big clear label on the packaging that advertises it is "mercury free". Many consumers are going to think of this as a CFL-replacement that does not contain toxic mercury.


Like I stated previously, there is much more to quality of light than just "color temperature". I tried a 2700K "warm white" LED and was not really happy with its light. Two light sources can be a different color but still have the same color temperature, so many people seem no to know that fact. In fact, color temperature is really rather inappropriate to describe light sources which are not black body radiators. In the current lighting marketplace, however, color temperature seems to be taken to mean how blueish the light is apparently. But this is not technically really color temperature. Regardless of color temperature, the current warm white LED light needs to be just a little more greenish (preferrably accomplished by adding blue-green frequency light, because paradoxically these LED's already have plenty of green frequency light, and while it would give the light a whiter color it would not help with CRI)

Of course I would be more concerned that sales went from $7,000 in sales in the 6 months ended june 2011, and $0 sales in the six months ended june 2012. I think that pretty much means that customers are voting with their wallets. I have a feeling the cost to manufacture is such that retailers have no interest carrying them as there is no margin it for them. Hence the ability to buy direct on their web-site ...... which no one seems to be doing ......



I have been wondering why no really true full spectrum LED's have been made available. You may have a point, though we will have to wait and see. I think high CRI LED's might have demand in office lighting (hopefully), but then again most offices now do not even use "full spectrum" fluorescent tubes, so perhaps people do not care (or do not know). And in many cases, it is not actually the office renters themselves that are buying their lights, so there may be a lack of direct incentive to make good aesthetic choices. With more marketing and consumer awareness, there would likely be more demand for higher CRI lighting.

I read that when this company first began taking order for these ESL bulbs through their site, they sold out within only 2 hours!
Apparently the media coverage online had caused several environmental blogs to write about, which generated considerable interest before it was even available. So while this ESL bulb might not really have a broader appeal, it certainly is being enthusiastically embraced by a small subgroup of consumers. There is a strong niche market.



Anders, I wonder if you ever get tired of hearing yourself talk because you talk and do not say anything.

1) Show me a link to a truly INDEPENDENT test that was completed by anyone remotely qualified.

2) You are an idiot because you keep making stupid assertions about LED not being as bright as the lumens would suggest. There is nothing remotely factual about that statement.

3) ESL are not directional ... R bulbs are not really directional.

4) Learn to read ... I said 3200K will not look like 3000K and definitely not like 2700K assuming the spectrums of the incandenscent and the ESL are the same .... which you claim to be. Please learn to read.

5) Color temperature is not at all about how "blue" something is. It is a measurement to translate a lights output onto the plankian curve of a blackbody radiator. It is not a guess, it is measurement and mathematics.

6) Your wonderful ESL bulbs had a green tinge indicating the spectrum was not what they claimed it to be.

7) You can guy almost blackbody LEDS from a few sources. However, the emphasis is on efficiency for the most part ... then again, you need to know where to look too. Oh, you would need to listen, and learn.

8) You argument about the "consumer" is not completely accurate. If it was true, no one would buy LED bulbs today, but they do because they know they will last a long time. That are you can get truly directional bulbs (can't in ESL currently). Along your argument, Apple would not sell phones at the premium they charge, but you would be suprised how educated consumers can be.

9) I work in lighting and never ever hear theft as a concern as light bulbs tend to be where people are ... the whole point after all. That acts as a theft deterrent.

10) Actually light quality being as good is not my opinion, it is based on the view of the Cree LED downlight which as been frequently reviewed and people love the light that comes out of it. Can you point to any TRUE reviews of the ESL? They are hard to find, other than some conjecture. It does not look like they sent a lot to lighting professionals. Oh, on that spectrum, what is that wicked spike in and around 610nm in the ESL bulb? The eye is of course more sensitive at photopic levels to the 610 spike than a 450 spike.

11) Did you know that low CRI of LED generally does not have a lot to do with the blue .... or your so called loss of cyan/magenta ..... which is actually at the levels it should be for a warm white black body. The issue is the lack of red ... which taken care of on high CRI fixtures.

Care to actually point to facts or should I just expect more hand waving?

Semiman
 
Your wonderful ESL bulbs had a green tinge indicating the spectrum was not what they claimed it to be.
It is just a slight greenish tint, and is mostly only noticeable when screwed in next to a halogen bulb in an adjacent fixture.
Halogen bulbs, for example, seem to have just the slightest greenish tint when compared to normal incandescent lights, especially when the halogen has a Reveal filter.

The good thing is that this tint is not caused by any sharp frequency peak, but rather just by the broad spectrum frequency distribution of the light.

Did you know that low CRI of LED generally does not have a lot to do with the blue .... or your so called loss of cyan/magenta ... The issue is the lack of red ... which taken care of on high CRI fixtures.
Any single huge frequency spike in the spectrum is genrally not going to be good for CRI. The issue is not just lack of deep red. These white LED's are also deficient in cyan frequency light, which in one way may be even more important (since it affects the color tint of the light, regardless of "color temperature". Also, the complete lack of violet frequency light in white LED's may or may not be a lesser issue.

I work in lighting and never ever hear theft as a concern as light bulbs tend to be where people are.
LED lighting is not really widespread and is relatively recent. Things might start to change when everyone has LED bulbs, and they have established themselves (assuming the prices do not greatly drop). The type of theives who would steal light bulbs are probably not any more informed about lighting than the average consumer. Why steal a bulb when they can just go to the store and buy a cheap one?

If the only lighting obtions available in stores were expensive LED's, I think there is no doubt we would see robbers breaking into buildings to steal LED's. As incandescents and fluorescents become "phased out" in the coming years, this could well become a problem in the future. When the low income population realises they have to pay out 40 dollars just for a decent light bulb, there are definitely going to be some of them that turn to crime.
 
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Hopefully we will see in the future ESL's that have more power, and are not just directional. But perhaps ESL's are best suited for directional lighting (particularly recessed lighting). Whether it is feasible to make omni-directional ESL's could be the topic for another long discussion. I think it certainly is possible, but the people building these things have much more experience with cathode ray TV tubes (directional). And then I wonder how much space an omni-directional ESL would take up. Might only be suitable for large globe lights, but this might not be so bad. After all, several ceilling fixtures throughout my house are basically just little bulbs inside a glass globe to diffuse the light.
A CRT accelerates charged particles then uses electromagnets switched at high speed to steer the resulting beam in a pattern across the target phosphor screen. The angle of deflection you can achieve with this method is somewhat limited, which is likely why the recessed downlight market is what they chose. If they produce something A19-ish, expect it to have the directional problems you complain about with LED. Only, LED can be rather omnidirectional with ease.

And also remember that these "500 lumen" bulbs suppossedly do a better job of illumination than the lumen rating alone would suggest (not sure if that means it actually has a higher light output, or whether the light it does output is just optimally distributed), this has been noted in several online reviews by different people. This is just the opposite of LED bulbs, which seem to have higher lumen rating than their actual illumination would suggest (although this might not be the case in recessed LED fixtures, perhaps someone who has actually done a comparison can comment? )
Substitute the term "lux" or "candella" for "lumen" and you'll get it right. Only it's hard to find lux/candella ratings on sources for general lighting ... hmm ...

This is not how the consumer thinks. You can argue that LED lights will save money in the long term all you want, but the vast majority of consumers will not care to understand or listen. Like idleprocess mentioned, consumers don't like to be made to think too much. If there are two "energy saving" products on the shelves, most consumers will just grab the cheaper one. ESL's could have an advantage in the actual marketplace. Even for people like us who know better, perhaps some of us just do not feel we can afford to buy all at once 12 recessed LED lights for a room.

And these ESL's would probably cost significantly less if they were being mass produced like the Cree LED downlights.
Have you see the electronics it takes to drive a CRT? Even though these need only scan a constant pattern, there are still high voltages and high frequencies involved.

These appear to be part of their driver circuits. 2 transformers, 2 big power/switching IC's, 5 big caps, 2 IC's, and numerous other small outboard components. Not shown - the electron gun, the windings / magnets, and the other bulb innards. They're going to be challenged to make any money at a $15 retail price.

LED bulbs are hitting the $10 price point with a steadily-maturing industrial base behind them. They're solid-state devices driven by DC power - which can be converted from AC mains power simply and cheaply.

Even the high-voltage ballasts for CFL's have a simpler task than a CRT driver - zap the arc into existence then maintain it. Component count on CFL drivers is pretty low last time I saw one cracked open.

Another point that you neglected is potential theft. As a greater number of people buy expensive LED lighting, it is quite within the realm of reason that these lights could begin to become the target of theft. A less expensive bulb (even one that does not last as long or save as much money) might make more sense in high crime neighborhoods or outside locations. So what other options for these people who want to use energy efficient lighting but absolutely hate CFL's ?
Wait ... what? Are you being serious? If your residence has been burgled, you generally have far larger problems than someone stealing your light bulbs, such as your TV, computer, jewelry, cash, firearms, etc being gone. If the thieves had enough time on their hands to steal your light bulbs, they've probably also relieved you of your plumbing fixtures, electrical wiring, door hardware, and flooring. But maybe they were polite about it and swept up after they were done.

Suppossedly these ESL bulbs have a better quality of light than LED's, and this would seem to be confirmed by looking at the spectrum graphs. Apparently better phosphors can be used when the excitation source is an electron beam rather than the UV from the mercury vapor in a CFL.
This article has the only graph I could find. Certainly not as spikey as CFL and a bit more full than LED, but also less smooth than incan/LED and the red spike is similarly situated.

Also, most of the reviews of the relative handful of pre-production units they released years ago seem to have been conducted by shills.

Perception of spectrum is quite subjective.

I found CFL's pleasing enough when they were novelties priced at about $10 each, but they became positively unsatisfying when I started shopping on price.

I personally dislike how the LED manufacturers are relentlessly pursuing 2700-3000K in an effort to replicate the incandescent - I'd much prefer something 4000-5000K, the color of daytime sunlight. But I recognize that I'm a minority, thus don't squawk about it too loudly, but do vote with my wallet when the opportunity presents itself.

Like I stated previously, there is much more to quality of light than just "color temperature".
The markets understand this too, which is why the markets seem to dislike the cheaper CFL's that cut corners on phosphor and produce horrid spectrum as a result. But CCT is a simple thing that's easy to remember and compare, unlike CIE coordinates or spectrum graphs. So long as the light has reasonably balanced spectrum, it's a useful comparison.

I have been wondering why no really true full spectrum LED's have been made available.
There were some experiments with near-UV LED's striking phosphor in an arrangement extremely similar to how florescent tubes work - I gather that package degredation from the UV exposure and lower efficiency than conventional white LED's lead to their abandonment.

The markets seem satisfied with the various warm white LED options out there - be it the phosphor mix on a blue die to produce warm or a cool white LED with red/amber LED's to fill in the red.

I think high CRI LED's might have demand in office lighting (hopefully), but then again most offices now do not even use "full spectrum" fluorescent tubes, so perhaps people do not care (or do not know). And in many cases, it is not actually the office renters themselves that are buying their lights, so there may be a lack of direct incentive to make good aesthetic choices. With more marketing and consumer awareness, there would likely be more demand for higher CRI lighting.
It's been my experience that most offices use whatever the building super's buddy/brother-in-law who he gave the service contract to as a favor can source the cheapest in order to maximize their profit. Like it or not, current-generation LED interior lighting will represent a step up over the mixed bag of T12's I've seen deployed in almost every office building.

I read that when this company first began taking order for these ESL bulbs through their site, they sold out within only 2 hours!
Apparently the media coverage online had caused several environmental blogs to write about, which generated considerable interest before it was even available. So while this ESL bulb might not really have a broader appeal, it certainly is being enthusiastically embraced by a small subgroup of consumers. There is a strong niche market.
Time will tell. Per Vu1's most recent blog entry, they're about to ship 40k units soon.


I've got to say, you're assuming that ESL has this potential to be amazing and marvelous on the basis of information you seem to have gleaned second-hand on a single beta product, but have contempt for LED - which has appreciable variety now - based on experience with one or two examples. Reassure me and tell me you're not a statistician...
 
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Any single huge frequency spike in the spectrum is genrally not going to be good for CRI. The issue is not just lack of deep red. These white LED's are also deficient in cyan frequency light, which in one way may be even more important (since it affects the color tint of the light, regardless of "color temperature". Also, the complete lack of violet frequency light in white LED's may or may not be a lesser issue.

You keep making a comment about LED lighting being deficient in cyan/magenta .... AND I WILL ASK AGAIN .... deficient compared to what? ..... cause relatively, they have more cyan/magenta than an incandescent or halogen .... so just what are the deficient to in comparison? If anything, without the blue there, the level of cyan/magenta is actually higher than a black body radiator. Would you like to rethink your argument of would you like to use your continously erroneous arguments again? Perhaps you would like to look at the spectrum on page 12 of http://www.philipslumileds.com/uploads/datasheets/DS61.pdf to see what a warm white LED with fairly good CRI looks like ... and how does that compare to the ESL? To me it looks better. The small blue spike is in an area where the eyes is not overly sensitive versus the 610 spike of the ESL.

Semiman
 
Not to break you guys up, but magenta isn't a primary color. It's a secondary / subtractive color formed by either the loss of green, or combination of orange-red and deep blue, something LED's have in abundance. Trust me, LED's have no problem rendering magenta.

Cyan is a bit more of a problem because we are all aware there's a trough between the primary blue emission of LED's and the gradual increase of green. I have mixed thoughts on this because while I feel this gap is neglected in high CRI ratings and shows how the classic standard is too generous the flips side is nobody seems to care. Cree already used mixed colors in their dedicated fixtures, and if 475-480nm really makes that much different they'd add them. It's kind of a straw horse arguement unless you are into really high CRI rendering. If this is the case, explain why nobody complains about 95-98CRI fluorescent tubes or halides which are hardly continuous.

Anyone who thinks wavelengths shorter than 450nm are required for perceptual color rendering is either a plant, owns a tanning salon, or works for the secret service checking for counterfit money. Nobody else will miss it. Rebels go shorter than 448nm, and that's bad enough.

The biggest problem with Plasma, ESL and Induction type lighting are simply the power supplies. Specifically in the case of ESL the high voltages requires are not something that can be generated with a couple bucks worth of ICs and caps like LED supplies can. You then need more robust insulation for these type of units, etc. There is simply no way to power them as cheaply as LED sources. CFL is a classic case of trying to make conventional fluorescent ballasts too cheap and disposable, and we all know what the result is - horrible reliability and smoking lamps when they burn out. ESL, Plasma and Induction are much harder to implement in cheap, consumer packages than CFL, if not currently impossible with on the shelf tech. As I've demonstrated along with others, LED's can even be driven quite efficiently with even basic fixed voltage sources. Heat is pretty much the only achilles heel.
 
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