'Solid-state' light uses one-10th energy, maker says

[Analog]

**broken link removed**

http://www.cbc.ca/technology/story/2006/09/27/tech-light-060927.html

Big energy player EnCana Corp. has joined a group promoting an Ottawa company's revolutionary design for light bulbs that could use 90% less energy than regular bulbs and last two decades.

The design by Ottawa's Group IV Semiconductor Inc. is being supported by EnCana and Sustainable Development Technology Canada. It was showcased yesterday at the National Research Council.

Group IV's light bulb of the future would employ an electrical current passed through silicon, with almost all of the energy involved producing light instead of heat.

The proposed solid-state lighting design would consume one-tenth of the energy of a regular bulb using semiconductors to produce light instead of gases or filaments.

"Solid-state lighting is gathering momentum as a means to reduce the world's energy consumption," Group IV CEO Stephen Naor said in a statement.

 

[audioguru]

So???
If they gave me 9.1 million dollars, I could also make an LED from sand.
I would make an LED from anything for 9.1 million dollars.

 

[justDIY]

a ten watt incandescent uses 1/10 the power of a hundred watt incadescent ... can I have 9.1 million dollars too?

rather than pie in the sky solutions like LED replacements for light bulbs, why not focus on a goal like turning off the damned lights! a bulb thats turned off requires no energy at all - the ultimate power saving device.

my neighbors are locked in competition to see who can make the outside of their house brighter at night ... they're wasting 100's if not more watts of energy for no purpose what so ever... not to mention that almost all the big commerical buildings around here have huge floodlights on them, lighting the corporate banner and the entire facade of the building.

 

[Styx]

justDIY I think you are missing the point

if you turn on a 100W bulb you ONLY get 10W worth of light
90W goes into heating, ie waste


using LED's the amount of wasted power due to heating is drastically reduced!!!

Look at the energy-saving bulbs they sell them boxed to say equiv to a 60W build (actual 18W)


wattage for lighting as become a unit in itself, anyone would know a 100W bulb is brighter then a 60W bulb and they roughly know how much it lights their room

IF an energy saving bulb only had written on it 18W they would go OMG!!! how un-bright will that be,



LED's are suppose to be even more efficent (ie turning more electrical power into lumin power) then energy saving so that can only be a good thing.
Sure turning a light off means it will use no power, but some places need the light on - you ever tried taking a piss in the middle of the night and the bulb has blown...

 

[justDIY]

@styx:

I think you're over estimating the quantum efficiency of LEDs ... energy saving bulbs that replace a 60w with an 18w are compact fluorescent, which do have a much higher efficiency than incandescent or led. LEDs on the other hand, are better than incandescent, but not enough to be considered 1/10th the energy ... compare electrical efficiency by lumens per watt and see what results you get, they're quite disappointing.

50 watt halogen bulb (mini bi-pin gy6.35 came up first in google) 600 lumens ... this yields 12 lm/watt

6 watt luxeon K2 white, highest bin, (5.775 watts actually) yields 140 lumens ... this yields 24 lm/watt

double the number of lumens per watt is pretty good, so a 100 watt bulb could be replaced by 50 watts of leds ... good luck keeping 50 watts of luxeon's cool enough to last, not to mention the cost invovled, let alone fit it into any sort of conventional fixture.

Nichia and Osram claim to have white leds in the 50-60 lm/w range, but I haven't seen either bring an actual product to market, and that's all that matters in my book.

 

[Madhouse]

And given the depretiation in light output over time for LEDs (even these newer high output types) the cost of replacement factor suddenly becomes a bigger issue....

 

[audioguru]

My city has replaced all traffic lights with very bright LED ones and they will pay for themselves and their installation in a few years. After that the savings of electricity and labour to replace bulbs is enormous.

 

[Madhouse]

I'm watching some of the older LED signs in this country and they are already starting to fade - thats when they actually work at all 'cus the solar panels used for them are not big enough to cope with the dark winter days! Thank god they haven't used those panels for traffic lights!

Anyhow thats another subject. I put some Lumen 3W LEDs up as outside lights at the farm the other week, measured the light output from them in complete darkness and will go back in March and check them again, against Lumen's spec....

I could be picky about them, but the flourescents are so cheap to replace nowadays, and I have them on for 16/20 hours a day... Yeh! I have to replace them every 18 months (five years my ar**)!!!

 

[Hero999]

How do you know whether it's the LEDs wearing out or just that the batteries dying or just aren't being charged enough?

Flourescents are still more efficient than LEDs and are a much more cost effective solution. LEDs are only usefull in situations where servicing is expensive or to replace direct light sources like hallogen lamps.

 

[Oznog]

Actually efficiency scale goes like this:
1. HID lights. This is used from yellowish streetlights to the bright white parking lot lights.
2. CCFL lights.
3. LEDs
3 1/2: Halogens. Large scale halogens, like used in headlights, is actually a very similar lumens/watt to LEDs.
4. Then you've got standard light bulbs
5. Small scale incandescent bulbs: Like in flashlights. Halogen or not, light bulbs don't scale well. Small bulbs are VERY inefficient, which is why LEDs look so impressive in this area.

 

[mramos1]

Oznog: Some of those lights take some time to come on (ok just one) and you can not use them in all applications here in the States. But a good list. I saved it.

Hero999: Good point. When LEDs fade at my house, I normally replace my batts. But they are in toys, not outlets. I have flourescents in all my outlets.

Madhouse: And what Country is this? Can you fill in your location.

Here in the States we must meet photometric numbers with the codes on commercial apps. So it really depends on what you are lighting.

 

[Oznog]

HID always requires a starting cycle, at least 1-2 min. If you shut down some HIDs the ballast won't let them turn on again for like 15 min. They are very expensive ballasts and bulbs. However, the efficiency is absolutely tremendous. All stadium lights are a type of HID. Yellow sodium vapor street lights are sort of under the HID class, although it's older and so different there's little reason to group them together. Sodium vapor's still quite efficient though.

LED is very effective for colored lights because the other solutions are so bad. All other light sources create a broad spectrum and the only way to get colored light is to filter out the undersirable wavelengths. To start with a balanced white off a HID or fluorescent- with a range of RGB components- it won't be red unless you block 2/3rds of the light because you only want the red. Since there are efficient red LEDs that only make red light, without filtering, they're certainly the way to go.

LEDs are often mistakenly believed to be an efficient light source. For little flashlights, yes. Larger stuff, not really. Had somebody who wanted to make LED headlights, the calculations with the best technology showed it would more or less break even with halogens, maybe slightly better under best case, if you could keep it very cool under high power levels. If the temp went up, they were less efficient. This was a hypothetical array of devices that would have cost thousands to build, mind-boggling to mount, aim, and encapsulate against the environment, and an elaborate cooling system.

 

[Hero999]

I agree Oznog but don't forget you can get coloured fluroescents if you want a particular wave lenght of light. Also LEDs are still a developing technology where HIDs, halogen and fluroescents have been fully mature for years. One day they might be the most efficient light source but only if nothing superceeds them, the only other lokely candidate is the Sulpher Lamp but it hasn't made anyone much money.

 

[NewBie/Jarhead]

@styx:

I think you're over estimating the quantum efficiency of LEDs ... energy saving bulbs that replace a 60w with an 18w are compact fluorescent, which do have a much higher efficiency than incandescent or led. LEDs on the other hand, are better than incandescent, but not enough to be considered 1/10th the energy ... compare electrical efficiency by lumens per watt and see what results you get, they're quite disappointing.

50 watt halogen bulb (mini bi-pin gy6.35 came up first in google) 600 lumens ... this yields 12 lm/watt

6 watt luxeon K2 white, highest bin, (5.775 watts actually) yields 140 lumens ... this yields 24 lm/watt

double the number of lumens per watt is pretty good, so a 100 watt bulb could be replaced by 50 watts of leds ... good luck keeping 50 watts of luxeon's cool enough to last, not to mention the cost invovled, let alone fit it into any sort of conventional fixture.

Nichia and Osram claim to have white leds in the 50-60 lm/w range, but I haven't seen either bring an actual product to market, and that's all that matters in my book.

NIST, the US standards Institute, tested the CREE XR-E as 75 lm/W @ 350mA continous, on a pcb mounted on a tiny heatsink. Details are here:
https://www.electro-tech-online.com/custompdfs/2007/03/NIST20XLamp20LED20Document-1.pdf

It also turns out that most incandecent, Metal Halide, Sodium Vapor, CCFL (compact fluorescents) are in fixtures that decrease their lm/W by 50%, due to fixture losses.

Grabbing a CCFL of GE's website, I'm seeing 54 lm/W. Toss it in a typical fixture, and it drops to 27 lm/W.

LEDs though, can be oriented to cast their light in the proper directions, so you don't have to redirect light going the wrong way, like you do in many fixtures, and take such a huge efficiency hit.

A great example, where they are using LEDs to save 40% of the power used by Sodium Vapor, and getting a much higher CRI light source (much improved color rendering), is quite apparent here:
**broken link removed**

 

[Sceadwian]

As someone who inspects for a living I can tell you color rendering index is VERY important, and can stifle the ability to simply differentiate the specular and chromatic properties of an object. Who cares if you're saving a little on your energy bill if your employee work performance goes down because the lighting sucks the life out of you.

If you've ever seen the movie the Matrix you'll know the kind of drab and depressing feeling that a limited CRI can lend to the environment, which the directors skilfully manipulated. Everything in the 'Matrix' was carefully color bled towards a green/gray hue and rich colors didn't exist. The 'real world', as depressing as it was to live in it, was rich and vibrant with stark color differentiation and depth.

A generic incandescent light bulb has a CRI of 100.
Sodium vapor runs in at a whopping 25 (I suffer with this at work because they think simply brighter is better for inspection)

Most other bulbs run in between 60 and 80, anything over a 80-90 CRI has a very low efficiency because the overall brightness is spread out in the broad spectrum required to get sharp color and specular differentiation. If you just wanted optimal light output for a human being with least power, you'd have every light on earth colored a horrible yellow hue at about 560nm's.
There is a blue(440nm) spike in the human perception of color but the combined green(540) and red(575) cones create a higher perceived brightness in the longer wavelengths because the spectrum perception is wider around there.

 

[Hero999]

I agree but I think he was also talking about the fitting losses. I'm still a bit dubious about the net efficiency of the LEDs though as those tests were conducted under ideal conditions and payed no attention to degradation over their life time.

Fitting losses can be avoided though I do agree that LEDs are probably more efficient than fluorescents when a direct light source is required. I would also think that LEDs totally whip fluorescents at longer wavelength where the phosphors won't be as efficient; having said that I still believe that fluorescents are far more efficient than LEDs at shorter wavelengths (UVA and violet).

In the end LEDs will probably become the most efficient light source but I don't think we're quite there yet.

 

[Sceadwian]

Just try to scale an LED lightning system up to an entire warehouse or building.

 

[NewBie/Jarhead]

Actually, Toronto is now working on converting their overhead area lighting to LEDs from a company that is using the CREE XR-E.

If you investigate further, you'll find many of the Metal Halide bulbs (and others) actually degrade quite quickly.

These high output power LEDs from OSRAM, CREE, LumiLEDs are typically rated in the 50,000 to 100,000 hour lifetimes- to 70% output, instead of the 50% output often found in bulbs. This is quite different than your grandpa's LED, which degraded quite rapidly, as these new LEDs have thermal resistances below 10 C/W, instead of 250-350 C/W found in the old 5mm LEDs. They also solder the die to the substrate, instead of using epoxy, which helps tremendously.


One of the issues with Metal Halide is that once you get them in a fixture, attach a ballast, and all that jazz, is you can easily end up in the 50 something lm/W range.

An example of a high bay setup, is shown here, and compared with other sources:
**broken link removed**

There are high end ballasts, that can help a bit with the efficiency issue, but usually, to get top end Metal Halide efficiencies, you are looking at a 400 to 500 Watt light, where the 100W ones can be as low as 80lm/W, before you take account for significant losses in the ballast and also the fixture.

Metal Halide degrade significantly in their output over their short 20-30k hour lifetime. Expensive ballasts can also help a bit with this, but they don't help the VHO or HO types that much (the ones that top the efficiency lists). Some of the bulbs drop to ~50% output at 30k hours, and often drop by 40% in as little as 12k hours- high end ballasts can help here, but again, they don't help much with the VHO and HO. This drop in output in such a short time drops you into the 50lm/W range pretty quick, before other losses, like the fixture and ballast. Metal Halide bulbs usually also contain significantly more mercury than even the old fluorescents do.

Additional costs occur for bulb replacement by maintenance crews.

Many of the Metal Halide bulbs shift color over their life, but some advances have been made here.

Even a number of the 400W Metal Halide bulbs suffer from lower CRI, 65. With a ballast+bulb of 83lm/W, this drops to 54 lm/W by 12,000 hours, and continues to drop over it's lifetime. There are some high end specialty bulbs that hold up better now.

The fixtures add additional losses on top of all of this.

There is a chart that compares some of the various brands of Metal Halide bulbs here:
https://www.electro-tech-online.com/custompdfs/2007/03/UPSS_O-Rated_comparison.pdf

Some typical light drop over life curves for Metal Halide:
https://www.electro-tech-online.com/custompdfs/2007/03/LM_at_a_Glance_0805.pdf

Notice how the lower wattage bulbs, which you'd use in a low bay setup, have rather short lifetimes of 10,000-15,000 hours. They also have lower lm/W numbers...


The problem is that folks will often pick out the very best bulbs they can find, picking the best lm/W from one, the best CRI from another bulb, and then not consider ballast losses, and also very significant fixture losses (they can easily hit 50% loss, but there are some that are a bit better). Then they will pick out the very best lifetime bulb from another bulb, and use the highest initial lumen bulb for their lm/W.

Unfortunately, reality is often another situation.

For a low bay install, have you a good 100W bulb that stands out head and shoulders above the rest, and could you link a datasheet? How about ballasts that go with this particular bulb? And fixtures with specifications for losses?

I'd sure like to know what the cat's meow is in Metal Halide these days, when you look at the complete system (bulb, ballast, fixture), as I have an area that could really use an efficient lighting setup, but once I look at reality, the numbers keep ending up abysmal. So, if you have any recommendations, I'm certainly all ears!

I'd also be interested in any bulbs that are made for shorter runtimes, as if you only turn the typical MH bulbs on for 1.5 hours, their life drops by 60%. This would result in a 10,000 hour rated MH 100 or 125W bulb ending up with a 4,000 hour lifetime.

They also recommend that you re-lamp the fixtures at 60% of the rated life, since the bulb lm/W drops so rapidly, and due to their color shift. I'm told that some ballasts can help with this also, but again, apparently it does not help much with HO or VHO bulbs much.

If I do this, then the 10,000 hour bulb that ends up at 4,000 hours when you have them on for 1.5 hours, I end up having to replace the bulb every 2,400 hours.

One of the Metal Halide bulbs a local home store carries is the M175U.

Spectral output graph:
**broken link removed**

Lumen Depreciation:
**broken link removed**

CRI:
65

Average rated life:
7,500 hours

CCT:
4200

Initial Lumens:
14000

Mean Lumens:
9100 when mounted vertical
8200 when mounted horizontal

Mean lm/W:
52 lm/W when mounted vertical
46.8 lm/W when mounted horizontal

And this is for the bulb only! Not counting ballast or fixture losses!

Reality can be brutal at times, when you do not look at things from a system standpoint.


Fluorescent bulbs also have plenty of short commings, and one can even purchase a special energy star labeled fixture, and end up with a system that is only doing 30 lm/W when all is said and done...


Even Wal-Mart is in the process of converting a few stores with an LED product from Gel-Core which is only doing ~30lm/W (low efficiency LEDs for current state of the art in the market, which are in the 70-90lm/W for high power parts, and even higher for low power parts).


The massive US-based retail chain will install LED lights in 500 stores, saving $2.6 million annually in energy costs.

Wal-Mart Stores is to deploy LED lighting from GELcore in low- and medium-temperature refrigerated display cases in over 500 U.S. stores. The retailer expects that energy cost savings of a 500-store retrofit -- one of the top energy-saving initiatives that it will pursue in 2007 -- will exceed $2.6 million annually.

Of note:
"In stores where the new GE LED products will be put to work, Wal-Mart expects to net up to 66 percent energy savings, compared with incumbent fluorescent technology."

And

"The combined environmental impact of a 500-store installation represents an annual 35-million pound reduction of carbon dioxide emissions. It also equals the good that comes from planting over 4,464 acres of trees or removing over 3,143 cars from the road for every year the LED lighting operates in place of fluorescent lighting."

http://ledsmagazine.com/articles/news/3/11/16?alert=1


Related stuff:

-Folks prefer LED lighting:
"The lighting within the display case was much more uniform with the LED lighting system compared to the traditional fluorescent system. The results from the human subject experiment show that subjects strongly preferred the display case with the LED lighting. Considering the luminous efficacy of white LEDs presently available in the marketplace, it is possible to develop a LED based lighting system for commercial refrigerators that is competitive with fluorescent lighting system in terms of energy use. The LED based lighting would provide better lighting than traditional fluorescent lighting"
http://www.lrc.rpi.edu/programs/solidstate/completedProjects.asp?ID=52

See page 44 for the scores:
**broken link removed**

From GelCore:
"Primary benefits of GE’s RoHS-compliant, UL-approved LED Refrigerated Display Lighting solution include:
• Improved product visibility with reduced light-source glare on products and floors
• Hidden light source provides better access to products for stockers and consumers
• More robust and better for the environment than fluorescent lamps because it doesn’t contain glass or mercury and it doesn’t produce UV or infrared light
• Up to 78 percent energy savings compared with VHO fluorescent lamps in a 5-door fixture
• Over two times the life of fluorescent lamps in a cold environment reduces maintenance costs and hassles (50,000 vs. 18,000 hours)
GE’s LED Refrigerated Display Lighting solution also saves watts by lessening the load on the compressor. For every light watt reduced in a frozen food case, the compressor works less hard, saving ~ 0.45 watts. On a 5-door case, the additional energy savings from a reduced load on the compressor, can reach 70 watts vs. T8 fluorescent; 134 watts vs. HO fluorescent; and 330 watts vs. VHO fluorescent."
http://www.gelcore.com/literature/GELcore_WalMart_refrig_announcement_DE_FINAL_111406.pdf


The product that is utilized:
**broken link removed**


And on top of it all, the LEDs they are using don't have very high efficiencies!

1280 lumens/41 Watts = 31.22 lm/W
http://www.gelcore.com/literature/RefrigSpecSheetWEB7_7_06.pdf

Also to consider with fluorescent lamps, most don't realize the large losses in fluorescent fixtures, plus the additional losses in the ballast, that cause the usable lm/W to drop quite significantly, from what everyone runs around touting. Additionally, in this case, the cool environment also comes into play, which benefits LEDs. But with fluorescent lamps it requires extra power input into the fluorescent bulbs to keep them warm, which also loads down the refrigerator cooling system, for even more losses.

 

[Hero999]

Now I do agree that:

• Generally (with LEDs being new technology) they also have modern ballast designs and will therefore have better ballasts.
• LEDs probably work more effectively at lower temperatures than gas discharge lamps. The semiconductor actually benefits from cooling which is especially detrimental to fluorescents because the mercury can condense and requires energy to evapourate.
• LEDs are a better for direct illumination than fluroscents because the light is all thrown in one direction.
• The lack of UV in LED lighting makes it less harmful to the eyes and it won't damage fabrics, plastics or food.
• The lack of hazardous substances is an advantage.
• LEDs are thougher and last longer.

Do you work for an LED company?

Apart from the fact that your post reads like an advert I have the following issues:

• LEDs are famous for changing colour over their life time because the phosphor tends to burn out long before the LED. The colour always tends to shift towards the blue end of the spectrum, If its a white LED, it will end up blue, if it's pink it'll still end up blue. I know that there are three chip LEDs but even then the dies don't wear equally and the colours don't always mix very well.
• Anyone with any sense doesn't enclose the ballasts in the refrigerating compartment so ballast losses increasing the load on the compresser is a non-issue.
• LEDs also require ballasts so you can't say that LEDs are better because the ballasts losses are lower. This isn't true, a high quality fluroscent ballast can be >90% efficient and a the same goes for LEDs. The resistor ballasts often used on battery power LEDs are often less efficient than the inverter used to power a CCT.

Just from my personal experiance:

• I hate the colour light most supposedly white LEDs produce, its harsh on the eye and is normally more blue or dull grey than white. I am aware that there are soft and warm whites available but their efficency is comparatively poor. I like the warm glow of incandescents which even the modern compact fluorescents emulate quite well.
• I've always found CCTs to be generally better all round performers especially where I want a diffuse light source - a 300mm tube will give me more light than 60 LEDs, uses less power and produces better quality light.
• LEDs make pathetic blacklights, for a start most so called UV LEDs product very little UV, most of the light is from around 400nm to 415nm which is violet, not UV, it does have some black light effect but will no make all blacklight reactive substances glow and isn't very good at exposing photosensitive PCBs.

 

[HarveyH42]

Doesn't UV light inhibit the growth if molds, fungus, and bacteria? I'd expect the UV-free coolers at Walmart will suffer from other problems...