Are ESL bulbs better than CFL or LED?
Vu1's conceptual design for its R-30 bulb.
(Credit: Vu1)A novel design for energy-efficient lightbulbs can produce incandescent-quality light and does not contain mercury like compact fluorescents (CFLs), according to manufacturer Vu1.
The Seattle-based firm has been working on an alternative to CFLs and LED lights for five years and just rolled out a demo video, below.
Vu1's Electron Stimulated Luminescence (ESL) lights can last up to 6,000 hours, about three to four times the lifespan of incandescents and comparable to CFLs. They produce 50 percent less heat than incandescents.
The ESL bulbs contain an electron source that fires electrons at a proprietary luminescent phosphor, which then glows. The screw-in apparatus is encased in standard lightbulb glass.
One disadvantage to CFLs is they contain about 5 milligrams of mercury, a small amount but enough to prompt some jurisdictions to ban dumping them in the trash. Burnt-out CFL bulbs should be disposed of with hazardous waste where possible or returned to the retailer, which then recycles them. The EPA recommends evacuating the room if a CFL bulb breaks.
ESL bulbs will be trash-bin disposable, according to Vu1.
Meanwhile, LED bulbs are energy efficient at around 40,000 to 50,000 hours a bulb but tend to be expensive. For instance, Panasonic's new EverLeds light will likely retail for around $40 when it hits stores in Japan next month.
Vu1's ESL bulb would be around $20 when it hits the market, according to spokesman James Quick. Vu1 might market the bulb in mid-2010 if its funding holds up. It plans to begin manufacturing at its EU plant by the end of this year.
The company says its ESL bulbs would produce light that's "essentially indistinguishable" from incandescents, contrasting it with the greenish or bluish light from CFLs and LEDs. To my eye, the ESL light in the video looks a shade colder than incandescent.
The prototype ESL R-30 bulb, which would replace a 65-watt incandescent bulb, has a color rendering index of more than 90 and a color temperature of 2800K, according to Vu1. It also turns on instantly and is fully dimmable.
ESL looks quite promising. Let's see if this bright idea makes it to market.
Crave freelancer Tim Hornyak is the author of "Loving the Machine: The Art and Science of Japanese Robots." He has been writing about Japanese culture and technology for a decade. E-mail Tim. 
Half of the heat thrown off? Seems that means that they use much more power than the equivalent LED, and therefore might well cost more when their full life-cycle cost is factored in.
CFL use 25% the engery of standard bulbs. LEDs use less than 10%. These bulbs are half the price of LEDS $20 vs $40 but only last 1/16 as long. Sure a LED bulb is $40 but the thing will last over 11 years even if if left on 24/7.
For both CFLs and LEDs, the quoted lumens has usually been far less than the same incandescent bulb. I've only dabbled a little with LEDs; it appears that many manufacturers of the consumer-grade bulbs have gone back to the drawing board. I picked up a pair of closeout LED bulbs at a reasonable price (that's really the only way to get LEDs at prices close to CFLs at this time).
I don't see them as making substantial inroads until they can replace the omni-directional bulbs that make up the vast majority of bulbs used.
Like the newly promised electric/hybrid autos coming online in a year or two, these esl bulbs can't get here too soon. Let's remove the mercury from the light bulbs, and get more electric autos on the road!
No worry, CFL's are here to stay for a while, atleast until 2012-2015. at that time LED's look to take over as long as the price contiues to drop. In the mean time, Pure Spectrum has a breakthrough technology that is dimmable, highest power factor(.96, much better than VU1's ESL bulb) cold to the touch, $4-$6 range, "instant on", very good light quality, energy usage in proportion to the dimming level, and hope to be on shelves very soon in Wal Mart and/or Home Depot.
Hey wow that's amazing.. no, not really... <-- Can you detect the sarcasm?
That's exactly how a CRT works... so what they have made is a mini black and white CRT you screw into a medium base socket...
Do they have a true full spectrum?
Do they flicker?
How do the 2 differ?
this new bulb does not have any special gas inside (some inert gas i guess). it has an electron gun that directly stimulates the photons on the glass.
Then at 6:48 you can see the internal bulb (outside of the consumer friendly shell) that has numerous pins on the bottom. This, along with the other description of the technology, proves that this is basically nothing more than a black and white CRT tube miniatruized into a light bulb form factor.
This brings us to three certainties:
1) It will require a moderate amount (= cost, waste, weight, enviornmental damage) of electronics in order to convert 120V into a very high (thousands) of kilovolt to supply the anode that will help suck the electrons to the front of the tube with the phosphor--a flyback transformer and voltage regulators.
2) It uses an electron gun to create a stream of electrons to illuminate the phosphor, and possibly some type of deflection system to spread the beam evenly across the surface (again requiring more electronics and high voltage)
3) It will require the use of LEADED GLASS to reduce the level of X-Ray radiation that could escape from the glass.
The fears with this are that high voltage can cause unwanted interference with other communication devices, and cause significant dust attraction to the surface of the bulb.
Also, the fear is the thin amount of bulb surface could easily allow xray radiation to leave it. Fronts of classic CRT's are over 1" thick leaded glass. This appears to be no thicker than 1/64" of an inch. Therefore the protection must be the space from this bulb to the external surface in the consumer friendly housing. What if that is cracked and allows leakage out?
Finally, there must be lead used in the glass in the bulb or the protective housing. Assuming it is (since that is the only thing that could help reduce radiation levels), then what is the benefit of replacing enviornmentally hazardous mercury with lead? (Other than the fact that the lead isn't gaseous/airborne when the bulb is damaged?)
A lot of questions need to be answered about this technology before deeming it safe, let alone affordable. It sounds like it's still a real energy hog compared to LED and other options, so how can it be a viable alternative?
I did some pretty basic research about CRTs and how they work, and discovered some interesting facts:
First, X-ray radiation requires far more voltage than would practically be available in a package this size. Another post quite correctly points out it takes about 25 KeV to accelerate electrons to sufficient energy levels to produce X-rays. Acceleration voltages of less than 25 KeV or so simply do not produce ionizing radiation.
Second, the X-ray exposures from modern CRTs are actually negligible by FDA standards. Most of the X-ray emissions in older televisions was the result of unsophisticated high-voltage regulation circuitry that caused electron acceleration voltages to be unreliable and often in excess of that critical 25 KeV number. This is no longer the case. Most modern CRTs only use a thin sheet metal shield, rather than a heavy lead one, to effectively reduce X-ray emissions to zero.
Third, since the energies involved are not sufficient to generate ionizing X-ray radiation, there is no need for leaded glass on the front of the bulb.
The units in the video are prototypes, and it is disingenuous to base any "fears" on their form factor. It makes sense that this technology would use similar test equipment and prototyping methods as conventional CRTs since the technologies are so closely related. I seriously doubt that all those electronics would make it into a production version, more for economic reasons that anything else.
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If they are characterizing fluorescent light as "green" - that used to be true 20 years ago, but it's rarely true today. Today we have a variety of fluorescent tube designs with different color characteristics, most of which are better than the old green FL lights. And modern electronic ballasts reduce the flicker substantially.
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All that said, CFLs still have a number of problems:
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1) Despite the fact that color rendering is improved, it's still not very good except on very expensive, specially-designed photographic bulbs using esoteric combinations of phosphors. Most FL bulbs emit a "discontinuous spectrum" of light, which distorts color perception and seems "unnatural" to one extent or another.
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2) FL bulbs still flicker more than incandescents or LEDs, although it is substantially better than 20 years ago.
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3) FL bulbs produce lots of UV radiation, which has negative health impacts, and can accelerate fading of dyed/colored items. This is why you will NEVER see FL bulbs used in fine art galleries that display valuable works.
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4) The well-known issues with mercury content. I think it's way past time for the EPA to require LARGE LABELS on FL bulbs stating this - on many FL bulb packages, you can barely notice this warning.
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However, I must take issue with the LED light level/colour drift over its lifetime, as phosphor brightness and colour accuracy drifts off over time in a regular CRT, so you have to assume this is the same with ESLs!
Personally, I'm going to wait until my CFLs die or LEDs/OLEDs become a better option in terms of price, lifespan, efficiency and light quality.
LEDs have plenty of problems too. Again, the commercial products are well developed but not typically feasible for the average homeowner. The heat issues require significant heat sinking which requires a lot of extra metal. All white LEDs are made from blue LEDs which is another issue. The warmer white you want to go, the more phosphors are needed, lowering the efficiency. There is also a weird phenomenom with blue LEDs that no one has figured out yet, called droop (http://www.spectrum.ieee.org/semiconductors/optoelectronics/the-leds-dark-secret/0) which is limiting the advancement in this technology. Also, LEDs are really stingy about the ratios of chemicals put inside, so a batch of blue LEDs may have differnet hues of blue, requiring binning to separate all into similar colors. Reports say some have efficiencies of 100 lumens per watt, about the same as T5 linear fluoresecnts, but by the time they are installed in a fixture, they are usually only about 50 lumens per watt, no better than a compact fluorescent. In terms of color and performance, there is even more variability with LEDs right now. Even at a commercial level, people are talking that they need their own rubric of measurement.
In the dimming category, commercial products work well, but neither of these work well residentially.
ESL is trying to fit the niche market of inexpensive residential products to fill in for the shortcomings that now exist. Yes, $12 is expensive for a bulb, but if you think back 5-10 years, when screw in CFLs first came out, they all cost this much too, and everyone scoffed then when they were encouraged to pay for them. If it turns out these are worthwile, then there will be incentives and utilities will be handing them out like they do CFLs now. I'd like to give the inventors credit enough to think about xrays. I'm sure they are watching for that. I'm not convinced this will be the one solution that will take over LEDs and fluorescent, but I think it could have its place and piece of the pie. Unless, that is GE's little laser trick actually works. Then we will all be back to good old, yet revamped, incandescents. Lets not forget how many different lighting sources already exist. What's one more!
The blog is at vu1corp.blogspot.com Thanks again for the coverage and the comments.
T. Ron Davis
Chief Marketing Officer
Vu1 Corporation
an a 19 - bulbs will sell for around $10. pretty soon , I don't see this approach as being
a viable option. Although somewhat better then current old technologies - this appears
to me to be the equivilant of the wankel rotary engine ( automotive analogy).
I've seen prototypes of Oleds that are truly disruptive compared to tangents like this-
it is a crt on an edison base - I'm certain this is a non starter - Come on 6000 hrs and mercury
the sslPro
The have numerous patents and are manufacturing and filling orders now worldwide. Utility companies are buying them up in the droves for their free distribution program. The utility companies love them becasue it costs them less to deliver the power to these bulbs due to the extrememly High Power Factor. ...which means the utility companies charge you less!
The also have a dimmable balast for linear flouresecents(yes, you will be able to dim flourescents), also at a fraction of the cost of normal ballast due to the fewer parts that they use in the balast. This will be huge, imagine a high rise office building in which the flourescent lights dim with the amount of sunlight coming in,....daylight harvesting at a fraction of the cost...HUGE SAVINGS.
Hopefully the bulbs will be on Home Depot and Wal Mart shelves soon.
I just want to reiterate, for people who keep referring to the color of CFL (or any other lighting) simply in terms of the "Kelvin rating", this is NOT the whole picture.
The reason why fluorescent lighting has historically been considered so poor from a color fidelity point of view isn't because of the overall "color temperature" (ie Kelvin rating, like "5000k", "6500k" etc), although that was an issue for very early flourescents.
The reason is that the spectral distribution of color is DISCONTINUOUS. This is a major distinction between the typical FL light source and incandescent. We can easily color-correct an incandescent source to "daylight" with a simple warming filter. In most cases, you CANNOT do this with fluorescent because the color spectrum is not smooth, and because there are now probably dozens of different FL phosphor combinations, you cannot easily determine which you will encounter.
Actually this problem is even worse with Mercury-vapor and Sodium-vapor lighting - but since those are typically only used for industrial or street-lighting purposes, it's not as much of an issue.
In order to distinguish one color from another, we need the entire visible spectrum of color present in our light source. Yes an incandescent bulb is "warm" or "yellowish" - but this simply "tilts" or "shifts" the color spectrum (as seen in a graphed view) rather than turn it into a "roller-coaster" like a typical FL bulb does.
What this means is that when you view an item under an FL light (and especially under Mercury-vapor or Sodium-vapor), your eye has a more difficult time distinguishing one color from another - this is independent from "color temperature" or "color shift". Go outside sometime under some sodium-vapor or mercury-vapor streetlights or industrial lighting, and look at how "strange" and even "monochromatic" colors appear. This is what I'm talking about. If for example you try to take a picture with a digital camera, your camera will not be able to find any white-balance setting that will correct this. This is not the case with incandescent lighting.
As usual, the various entities with an axe to grind (and ignorant consumers) end up oversimplifying the issue. It's not as simple as it seems.
Sorry - meant to write "with a cooling filter".
I'm already of the persuation that I like the lighting from my new fluorescents better than the old incandescents. I still had a few old incandescents in lamps that weren't used often and they were starting to stick out like a sore thumb when they were turned on with the other lamps. I've now got 90% CFLs in all major lighting and they work well. I've still got one halogen torchier and a few halogens in fixture lighting and one halogen reading lamp. The rest is all CFL. I can light the house up twice as nicely for almost half the cost.
Given GE's borderline fraudulent marketing of the previous generation of "Reveal" incandescent lighting, I won't be holding my breath about alleged wondrous color rendering abilities of a "Reveal" CFL bulb either.
The post whose URL I'm pasting below goes into some detail about why the incandescent version of "Reveal" bulbs were not what they were cracked-up to be, and is a decent overview of the kind of issues I've been pointing out with CFL color-rendering.
http://forums.dpreview.com/forums/read.asp?forum=1000&message=22418166
In short: at the very least, you need a "CRI" (color rendering index) spec in addition to the traditional "kelvin" rating to ascertain whether a lighting source has a decent chance of looking like "natural light". And that doesn't even tell the whole story.
Now I grant you - many people are not as picky as us photographers are when it comes to lighting quality. But I simply want to reiterate that we are in many ways comparing apples and oranges when it comes to these assumptions that certain forms of energy-saving bulbs are just "incandescent without the energy cost" - when it comes to color quality as well as other ergonomic and health factors.
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- by supafuzy September 22, 2009 12:25 PM PDT
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