No more twisty bulbs for me! I’ve installed a new LED lighting system for my home that beats twisty bulbs in every way. It has been awhile since I discussed technology here, so this will be an interesting diversion for many readers.
I’ve always been a fan of alternate energy and improved energy efficiency, and I don’t just write about it like some people we know, I do things about it. I try out new things, I do the work. Longtime readers of my blog know that I’ve done two solar power projects, drive an electric car for my local short distance jaunts (I have two now, a really sharp new model, but that’s another story). I’ve put a 10KW solar array on my home, plus a 125 KW solar array on one of our local schools when I was a school trustee. I’ve retrofitted my home with CFL’s in some places, as well as installed timer switches on many of our most commonly used lights. I live in an an Energy Star rated home. However, I’ve not been all that pleased with the lighting that came with the house. Now I’ve changed the largest wattage draw of lighting in my house from incandescent to LED lighting.
No matter what you think about the veracity of global warming claims, there’s really not much of an argument anyone can make against improved energy efficiency as a way of reducing all emissions, not just CO2. Literally, CO2 sucks all the oxygen out of the energy efficiency issue. The goals of full spectrum pollutant reduction can also be accomplished via improved energy efficiency, and with much less rancor, in my opinion.
I’ve never liked the twisty fluorescent bulbs, even when practically given away. They are slow to illuminate, don’t live up to manufacturer’s lifetime claims, and contain toxic mercury making them a disposal hazard. Watts to like?
Up until now, I hadn’t liked the color temperature of the light that LED bulbs had put out. They were mostly a harsh blue-white. Now, that’s been solved.
So that was my weekend project, improving my energy efficiency. It was painless, fast, and the result was fantastic.
The problem: 5 recessed incandescent lighting fixtures each with a 65 watt bulb for a total draw of 325 watts. My kids leave the hallway lights on constantly as it is the most trafficked area of the house.
The solution: swap in LED recessed lighting fixtures at 12 watts each for a total draw of 60 watts
A liberal professor friend in the bay area (who also happened to be best man at my wedding) turned me on to these new recessed incandescent fixture replacements from a company called CREE Lighting. I was impressed the first moment I saw the light they produced. It was warm, not harsh, and even better, it worked on a dimmer control.
The neatest trick with these lights is that they combine yellow and white LED’s in a matrix to get a color temperature that is 2700K or 3500K (your choice) which makes them give similar light to incandescents. Here’s what they look like inside:
Besides making less heat through lower power consumption, They also seal against the ceiling better than incandescent recessed lighting fixtures which are essentially open to the attic.
Here is what it looks like outside:
I bought one for my office immediately, to put directly over my desk, replacing a 75 watt flood in a recessed fixture. It worked out great, so I decided to do my entire house hallway of 5 fixtures.
Here’s the details on this new technology:
Product Description
The LR6 is a downlight module for new construction and retrofit that installs easily in most standard six inch recessed IC or non-IC housings. The LR6 generates white light with LED’s in a new way that enables an unprecedented combination of light output, high efficacy, beautiful color, and affordability. U.S. Patent # 7,213,940 issued. Numerous patents pending.
Performance Summary
• Utilizes Cree TrueWhite™ technology
• Nominal delivered light output = 650 lumens
• Nominal input power = 10.5 Watts
• CRI = 90
• CCT = 2700K or 3500K
• Dimmable to 20%
• Three Year Warranty
Cree TrueWhite™ Technology
• A better way to generate white light that utilizes a patented mixture of unsaturated yellow and saturated red LEDs.
• Tuned to optimal color point before shipment.
• Color management system maintains color consistency over time and temperature.
• Designed to last 50,000 hours and maintain at least 70%
of initial lumen output.
Construction
• Durable die-cast aluminum upper housing, lower housing, and upper cover.
• Integrated thermal management system conducts heat away from LED’s and transfers it to the surrounding environment. LED junction temperatures stay below specified maximums even when installed in attic insulation with temperatures exceeding 60 degrees Celsius.
Optical System
• Proprietary optical system utilizes a unique combination of reflective and refractive optical components to achieve a uniform, comfortable appearance. Pixelation and direct view of unshielded LED’s is eliminated.
• White Lower Reflector balances brightness of refractor with the ceiling to create comfortable high-angle appearance. Works with refractor to deliver an optimized distribution that illuminates walls and vertical surfaces increasing the perception of spaciousness.
Electrical System
• Integral, high efficiency driver and power supply. Power factor > 0.9 Input voltage = 120V, 60Hz
• Dimmable to 20% with certain incandescent dimmers (reference www.CreeLEDLighting.com for recommended dimmers)
Regulatory and Voluntary Qualifications
• Tested and certified to UL standards. Suitable for damp locations.
• Utilize GU-24 base for new construction projects in California or other areas where high efficacy line voltage sockets are required.
• Exceeds California Title-24 high efficacy luminaire requirements.
• ENERGY STAR® qualified Solid-State Lighting Luminaire.
Full Spec sheet here
The company has a savings calculator here
Installation was easy. I’ve photo documented it below. If you are interested in reading how, here is the installation manual in PDF form, and more info here.
FIRST and most importantly: turn off your a/c circuit breaker that supplies power to the lights.
The box:
The contents:
The top with special socket:
One of the five incandescent flood lights to be replaced:
Beginning disassembly, take out the bulb, pull down the trim ring:
Squeeze the spring clips and pop them off:
Cut the wires off the existing socket:
Install the wire splice block:
Add the new socket and crimp the splice block:
Socket installed:
Final step, all it takes is two twists. I couldn’t hold the camera and do this so I’m relying on diagrams. Twist the socket onto the fixture, push the fixture into the hole and twist until it locks into place:
New LED fixture installed:
Can you tell which ones are the incandescent floods and which one is the LED light?
The one in the foreground is the LED lighting. It puts out more light than the floods it replaced, and uses 1/5th the energy.
All done, three in the main hall, one in each side hallway are not shown:
Want one? Get them here from a company that operates in my town, called Lighting Direct:
UPDATE: I got called away before I could finish this post, so here’s a few more points on why I’ve done this swap.
1) I’m usually an early adopter of technology, this is something I’ve been looking forward to. But it is not for everybody yet.
2) I bought a 5 pack, so I got 20% off. You can call the company at the link listed above and ask for similar discounts. There’s also other sources online: here, here. Some commenters have asked about screw in LED models, here’s one also based on CREE’s patented LED illumination engine.
3) In California, I won’t be able to buy incandescent bulbs soon. This was my way of beating the state mandate on my own terms.
4) These have an advertised life of 50,000 hours. I figure if they log 8 hours per day, I’ll get 17 years out of them. They’ll pay back long before that.
5) CFL floods aren’t that cheap either, and from experience I only get 2 years out of them. For example I can buy a CFL flood at my local ACE Hardware for $14.99 plus tax. If I have to replace it every 2 years, I’m into some significant cash and significant disposal issues in a few years. Even with the higher cost of the LED units, I see myself as still being ahead in the long run and I’m not generating mercury toxic waste.
6) These lights are sealed, so there’s no air leakage to/from the attic. This should help on heating/cooling issues since when the wind blew above 15mph I could feel air being blown into the old recessed lighting fixtures. Not anymore. It will keep dust and attic insulation fibers out of the house also.
Tony Osborne,
If you read your wiki link on the Jevon’s paradox, you will see that according to wiki (Wili Connelly?), the Jevon’s paradox doesn’t apply to conservation measures when mandated by Government.
The original light emitting diodes (very early 1960s) were Silicon Carbide, green, and very inefficient. The later red series overcame the efficiency problems using different materials, followed quickly by green, yellow, and other parts of the middle and long wave end of the visible spectrum. Finally, satisfying the needs of the auto industry, the right combination of materials and geometry produced blue, and as a sidelight, UV models. IR came along with red. But, what about white??? Well, if you examine white LEDs, they are UV chips with a phosphor, sort of micro versions of fluorescent design. So, the color spectrum is dependent on the phosphor choices, which continues to be an area of rapid development and lots of disappointments. CFLs have been around for a little over 20 years and are obsolescent. LED lighting has been around for 4 or 5 years, but remember, progress is exponential, so they can be expected to be replaced by something better in maybe 7 to 10 years. I’ll buy them on the end of production close-outs. In the meanwhile, Incandescent bulbs will still be around, in spite of good intentions. Otherwise, it will be pretty dark in your oven.
Martin Hale,
You should go into a side business making LED fixtures for amateur home indoor gardeners like myself who are electronically challenged. Reading about your experience has given me the idea that I may soon be able to afford a proper indoor herb garden, currently impossible due to lack of windows facing south and the expense of running grow-lights. I just need to find a source. On the other hand, hope dope growers are too stupid to catch on to this! Great post!
About three years ago at the outset of the EU’s stupid ban on incandescent lightbulbs, to be replaced with oh-so-wonderful ‘low energy’ lamps, I went on record suggesting that these were the lighting equivalent of eight-track stereos.
So it has proved to be – this ban now SO yesterday, due to the inevitable development and wider use of LEDs, which apart from consuming about one-tenth of the power of so-called low energy lamps, have an almost infinite life (c. 100000 hours). Oh – and they don’t contain mercury like the low-energy lamps, which WILL find its way into the groundwater…
I see that nobody made it to the bottom of my first post. Incandescent bulbs are going to be outlawed in Ontario in 2011, and my query about substitutes for incandescent bulbs in ovens, appliances, and oven hoods has not been responded to. I am not aware that exceptions will be made for these applications. Are there any non-incandescent bulbs that are safe and reliable alternatives?
Anthony,
This is slightly off-topic, but I see that you have a large attic fan. How do you keep yours from venting 8 million BTU into the attic (or vice versa) when not in use? I’m guessing that you probably did a decent job of sealing it. I’ve tried a lot of solutions at my house, but nothing really works. (Right now I have strips of R49 sitting on top of it, but I have to climb into the attic to remove/replace every time I want to use it).
-EDT
REPLY: Good question, and pretty simple really. I got a large 2″ thick piece of rigid foam insualtion and put it on a hinge on one side of the wooden frame box that houses the attic fan (I had to build it up just a bit so that the motor did not protrude over the top edge.)
The foam is light enough such that when I turn the fan on, it will blow the foam piece upwards and it swings away on the hinge. I put a stop set bracket so it doesn’t go past about 75 degrees. Turn the fan off, the foam lid settles back into place and seals the box.
– Anthony
Thanks for a great piece, Anthony!
These would presumably be more economical in new construction than as retrofits. But do they stand alone, or have to be installed inside generic cans?
Also, how do you get the socket loose from an already installed can? Don’t you have to go above the can to unscrew the nut holding it in place?
I have 8 incandescent cans (on 3 circuits with dimmers) in my kitchen that would be good candidates for these. They leak so much cold air that just closing the opening would save a lot of heating fuel (and maybe even cooling power). Any heat generated by my incandescents probably goes more into the attic in the winter than into the house, so it’s probably lost anyway.
REPLY: They also offer a version with an Edison screw base. All the cans I’ve seen have the Edison socket either as part of a spring loaded press fit inside the can, or on an L bracket secured by a wingnut on the inside of the can. Either is easy to remove. – A
Since the savings over CFLs is really based on life expectancy more so than electrical use, I’d be more inclined to go this route if the company backed up the 50,000 hour claim with more than a 3 year warrenty, since even on 24 X 7 6 years is only 52,000 hours, so why won’t they step up to at least that long?
As for CFLs (and life expectancy), I only buy CFLs that don’t require returning defective bulbs even if these bulbs cost a little more (the savings from CFLs comes from thier long life and low electrical usage, so small differences in initial cost is not that much of a factor), and I write the date installed on the bulb base with a Sharpie and the 800 # to call.
If a bulb doesn’t live up to expectations, I get a refund.
As for Mercury, Home Depot and other Home improvement companies now offer drop off places for the bulbs.
Nice article. I have replaced nearly 30 light bulbs in my house with CFLs and will be happy to replace them with LEDs when they are inexpensive enough. It bothers me that CFLs so rarely last anything close to the lifetime claims of the manufacturer. I’ve been making trips to Home Depot’s customer service counter for their free disposal program for CFLs. They don’t advertise it to much because I’m sure it costs them some $$$. But it makes me feel better to know that the CFLs are properly disposed of. The program could use a little more exposure so these dead CFLs don’t end up in the land fill.
Great stuff.
LED technology is coming along in leaps and bounds. Although still quite pricey, and have some have mentioned only the ‘rich’ can afford, it’s all the more reason for government to stay out of legislation.
It could be argued that the threat of legislation, and face-palm legislation in more, erm, ‘progressive’ (I don’t think the swear filters pick up on this, yet) localities, has driven the technology, but the free market has a way of solving perceived or real problems.
Increased consumption of these devices, lowers the cost and increasing the quality. Additionally, as more ‘rich’ people buy such products to reduce their energy consumption, this relieves strain on the energy producers and does have the net effect of reducing the cost of energy allowing the ‘poor’ to better their lot in life: the key to prosperity is cheap abundant energy.
That is, a lower energy cost allows the poorer user to purchase such devices, further lowering their energy consumption. A rise in energy cost is an exponential cost since everything is directly related to the cost of energy.
Any energy legislation has the direct effect of increasing energy cost, hurting those who can least afford it, while giving those that can [afford it] a free pass to consume as they wish. Even with a stagnant technology market, those that can afford it always have methods to completely bypass any legislation imposed (richer people tend to have a greater array of ‘loop holes’ to avoid paying taxes – a direct result of progressive taxation), which further transfers the burden to those who cannot do so, and must pay the tax.
(Note, a ‘tax’ is also a fee or other additional financial burden required to meet any law or legislation, in addition to direct or indirect taxation).
These lights are ok but expensive. LED’s tend to shine all of the light in one direction but lights containing numerous LEDs partly solves that problem. I don’t think that LEDs are good enough or cheap enough to interest the masses just yet but they certainly will be in future.
Another point that I’d like to make is that we should have more nuclear power then who cares if we have low energy lightbulbs or long lasting conventional ones (which incidently help to warm your house too). I’m all for saving resources or curbing polution but that doesn’t necessarily mean we have to live like energy paupers.
0.10 per kwatt, 65 to 15 watt reduction = 50 watts x 8 hours x350 days a year x 0.10 per kwatt= 14 bucks a year. payback 5.7 years if it doesn’t break down. There is a three year warranty on the product so thats a gamble. If the price goes down to 42 a unit, then it would be worth the risk. I know there is off sets on both sides of the discussion(ie, I use those toxic swirly bulbs at 28 watts instead of 65 watts bulbs, or the cost of replacement bulbs over that time period) but the price would have to come down by 50 percent. That or increase the warranty to 6 years. LEDs last for every but the transformers are the week link. So here is what I’m really asking. All you early adopters, buy buy buy and bring down the price for us cheap hawks.
Just fyi, my brother went all LED in his house up in Washington using some other brand not mentioned in this post. He had a 50% failer rate with in the first year. I hope Anthony gets better results.
I live in Vermont. I am guessing that my oil bill will go up if I stop using incandescent lighting. It is not like I will make it up in air conditioning in the summer either, when days are much longer and the lights are used less, and I rarely use air conditioning anyway.
I have LED above-cabinet lighting in my newly remodeled kitchen and love it! Often the only lights on in the kitchen during the evening are those LED lighting strips. I’d estimate I have a total of about 60 watts and they are great. However, that project cost me over $700 and I did the install mostly myself (had a helper when pulling wires through walls…) Reading this thread, now I know I can replace at least four recessed lights in the kitchen, and several more in the halls. However, three other recessed lights in the kitchen are “angled” recessed fixtures and that may pose a problem. They don’t take floods, only regular-sized bulbs. I currently have a twisty and a couple of regular incandescent bulbs in those three lights. It would be great to have a 65W equivalent in that form factor.
Also dimming can be an issue. I am using good-quality Lutron sold-state dimmers and can’t completely turn off the LED lights. You can’t see that they are still on unless the room is completely dark, and it looks like they are perhaps running at 3% power. However, that’s a feature, not a bug because it’s never completely dark in the kitchen, kind of like having fancy night-lights in there.
I took a slightly different approach to the impending ban on incandescent bulbs. When congress passed the legislation, I calculated my annual bulb usage, matched it against my age and life expectancy and bought a lifetime supply in case lots at wholesale while the prices were still low.
Total cost: $360! If I’m still here in 20 years I’ll consider switching. I find that the older I get, my focus is not so much on ROI as it is on thumbing my nose at the government.
I don’t keep any of these lights on for 8 hours a day. Also, with a lower electric rate and current bulb price of $1.94, I get a payback of 20 years. I think I’ll wait for the prices to drop.
The better story was the use of LEDs in traffic lights. They aren’t warm enough to melt the snow off and were causing big problems. That law of unintended consequences will get you every time.
LED is a very good technology, I’ve been using some of the lights for my volunteer theater productions for a couple of years now (http://www.colorkinetics.com/). For this sort of work the 5W variety has helped tremendously both in direct energy draw and cooling costs considering that we replace several 575W lights with a 250W array.
The primary draw back on them is that they are a direct-view light. ie works great for down lighting, not so great for standard floor lamps. Progress has slowly been happening to make LEDs better for common household use including more color temperature selections, and reducing the amount of color splay.
One not mentioned problem – heat. Note the heatsink on the LED housing. I have used CREE LED’s in portable devices, work very well. But they get hot. A 7W 3 LED source without a heatsink can melt the soldered connections. BTDT What?!? How can that be?
Maximum efficacy for visible light sources is between 500 and 600 lumens per watt (I have seen both numbers, one on Wiki, questionable, the other in Photonics Spectra.) LED’s are around 70 lm/w, at least the ones you can buy. IC’s between 10 and 15 lm/w. So LED’s are much better.
Except that those clunky old IC’s dump the wasted energy mostly as mid and near IR into the room. LED’s do not. Very long wave IR, dumped out of the heatsink. Into the space surrounding the fixture. Depending on construction, a potential fire hazard. CFL’s are only a bit better. If you live in a colder climate, IC’s aren’t all that bad, as they do heat your house.
Not having big bucks to spend on newfangled stuff, I use CFL’s in the ceiling. Bought a couple of Sylvania 75W equivalents back in 2002, $25 ea, with a “7 year” life. Precisely on schedule, they died, within a week of each other. The replacements, from China, $7. Take forever to warm up or whatever they do to reach full brightness. Were it not for the cost, I would stay with Tom Edison’s version.
As for the EMI comment, I haven’t seen it. CFL’s and electronic ballasts run at 20-25 kHz, a simple metal enclosure keeps that, well, … enclosed.
I installed ten Cree LR4 fixtures as task lights during my recent kitchen remodel, and they’re honestly the best lights I’ve ever installed. The LR4s are essentially the same as the LR6, but fit in a 5-inch can (yes, the “4” in LR4 really isn’t 4 inches.)
Believe me, I really wanted to put in halogen cans. But living in California, my hand was forced. CA Title 24 requires at least 1/2 the lighting wattage in kitchen areas to be from high efficiency luminaries.
Since I absolutely loathe every single CFL can I’ve ever seen (yes, even the current generation ones), I had to give these a shot. But at $200 *per can* (including light engine, can, and trim piece), they’re not for everyone.
The light color and quality is phenomenal. No one ever guesses they’re CFL cans, and they really look much like halogen. They’re bright, dim to a pretty low level (no, they won’t go to 1%) without any flicker, and just add a very pleasing light to the space.
If they were half this cost, I’d replace all my halogen cans in my home in a heartbeat.
My house is almost entirely recessed IC lighting, of which except for the kitchen. are all on dimmers. That means 90% of our lighting is very rarely ever run at miximum (we like the more subdued lighting). At $98/fixture, it would cost us close to $4000 to go to those LEDs. Like Butch said, instead I have been stockpiling cases of 65W indoor floods bought for much much less cost; total right now around $200. Like him also, I figure we’ll be in this house maybe another 10 yers before retiring and moving out. I should have enough IC’s to last until then and maybe some left over for the new owners.
If one goes to the DoE energy info site, one can see that lighting is less than 5% of household energy use. Space heating is first at 50%, with appliances 2nd at 30%, and water heating 3rd at 17%. These are the places where the biggest energy conservation efforts should be aimed.
I have also seen most of my CFL failures with the Silvania bulbs. Their life time was so short (weeks) that I will no longer buy any of their CFL bulbs.
I went to a low light environment years ago. I have two main lights that I use most. Both have 10w (electrical) CFL bulbs in them, installed in torchiere style floor lamps. They provide low level general room illumination in the living room and the study where my computer is. In the winter time they run for perhaps 5 hours a night each on average. The bulbs themselves sell for $1.99 USD and I have not had any burn outs with these bulbs, so I have no clue how long they will last.
At 5 hours/night and 10W power consumption each, that is an electrical draw of 50 watt hours per night/lamp or about 1.5 KWH per light per month. At an average power cost of 0.12 cents per KWH they cost me about 18 cents a month each. It makes no sense for me to try to reduce my lighting power consumption lower than this level. I would burn up 10 months power cost in gasoline just driving to the store to buy a replacement bulb.
When I switched to this low level illumination, I also added some small local spot lighting for those occasions when I need/want higher local light levels for reading or some other task.
In most cases, these are using 27 w (electrical) warm white CFL bulbs with 5500K color temperature. I might turn these on for an average of 1- 2 hours a day while reading or doing some other close work. I may go several days without using them at all. At 2 hours a day (total for spot lighting), these lights would cost me 3.2 KWH of electrical power ( probably closer to half that except in the dark days of winter). Net cost for them would be 39 cents a month at most.
My kitchen in the apartment has a fixed long tube fluorescent fixture but it is only on for an hour or so each day when fixing dinner. With (2) 14W tubes that works out to about 0.8 KWH per month, making my power cost for the kitchen at 10 cents a month.
Throw in another 10 cents a month for the other room lights that get switched on for minutes a day, and my total power bill due to lighting is on the order of $0.80 USD per month — ie. totally insignificant compared to other uses.
I spend about 8 – 16 hours a day with my desk top computer on each day. It on average consumes 100W. At an average usage of 12 hours a day, that works out to 36 KWH per month or around $4.33 USD per month.
My last electrical power bill for the month of January was $32.27 and most of that was to run the blower on the furnace (average $1.16/day)
It makes no sense economically for me to try to cut my lighting power consumption below those levels. At the current cost of LED lighting, especially given I have a stash of spare CFL bulbs that will last me for many years at a minimum.
From a technological point of view it is nice to see the development of new more efficient designs, but even with today’s technology, you can reduce your lighting power requirements to completely insignificant levels with a small change in life style and a change to low level general illumination augmented with natural light and spot lighting for tasks that require good light levels.
Larry
Butch (08:56:55) :
“I find that the older I get, my focus is not so much on ROI as it is on thumbing my nose at the government.”
I gotta love ya for that one!
Thanks for the “How To” essay Anthony. It saves the tinkerers a lot of time and grief to know there are commercially available solutions.
Cree is certainly one of the big(gest) players in the LED Illumination Industry, so it is nice to see an actual shovel ready solution from them.
The statndard peak of the Photopic Luminosity curve is 680 Lumens per Watt, at something around 555 nm in the Grellow region.
It is known that the very highest efficiency “White” light reaches 400 Lumens per Watt for a monochromatic pair of sources at 448 nm (blue) and 568.7 nm yellow; but even though that source is visually white; it isn’t a usable white light “illuminant”, since it contains no other spectral components. It can at most be used as a flashlight.
The most common “single chip” white light LEDs use a Blue Gallium Indium Nitride LED emitting at about 460 nm. This wavelength matches a very strong absorption line in Cerium doped Yttrium Aluminum Garnet; which is a somewhat broad yellow emitting phosphor. The resulting yellow emission plus the residual of the 460 blue, not absorbed, is balanced to result in a “white” overall emission. Well yes it is a rather cold white, and is noticably deficient in any read emission, so it is not a particularly good whit elight either. Some makers add a red phosphor to spike up that part of the spectrum, to make a warmer white, that gives a better color rendition for ordinary scenes, and objects.
The three color LED approach is another way to do it; and does offer some advantages; particularly tho possibility of color tuning the final light to suit your mood.
The big problem for LEDS is not so much efficiency, but the ability to make High power devices. the light is produced in a very small volume, and small surfgace area, and a lot of waste heat has to be extracted to keep the emission efficiency from degrading too much.
Another problem is that LEDs are current operated devices, with a forward Voltage that is a Logarithmic function of the current; and unfortunately a negative coefficient function of temperature.
In low power indicator light usage of LEDs, it is simple to run the LED from a current source that may be just a resistor limited voltage source. Thgat unfortunately is a great waste of power in the driver circuit, which negates the luminous efficiency of the LEDs.
So high efficiency driver circuits are a big area of technology for LED power usage, to retain the hard won luminous efficiency.
But it is coming; and it certainly is the way to go.
And like Anthony; I have always been in favor of efficient use of energy resources; or anything else. When you grow up in the middle of a World War, you don’t take waste as an acceptible way to go.
CFLs are also a huge source of RFI, that sooner or later is going to become simply unacceptible. The Mercury problem is also a big negative for CFLs
Ordinary cylindrical fluorescent tubes; just happen to have a very useful optical geometry, that can in principle be optimally shaped using non-imaging optical concentrators, to restrict ALL of the emitted light to a carefully controlled output angular beam; without the use of egg crates, and other energy wasting baffles. So far, nobody seems to be designing industrial fluorescent fixtures using the ideal CPC optical configurations.
LEDs have reached the 100 Lumen per Watt point; but they are still a long way from the theoretical 400 L/Watt maximum. I believe that those in the industry think they can eventually get to 200 Lumens per Watt. That’s pretty damn good. I can still remember back in 1965 in St Louis Mo at the Monsanto Chemical Central Research labs, looking through a microscope in a darkened room, at the dull red 640 nm glow from a primitive Gallium Arsenide Phosphide LED wafer. Nowadays; LEDs are subject to emission safety standards similar to those for laser sources; to prevent eye damage.
The Aluminum Indium Gallium Phosphide amber LEDs, are so bright, you can do real damage to your eyes if you look directly at a typical 1 Watt packaged lamp.
I see that Amazon.com has the following listing:
“LED 60 Watt Incandescent Replacement: Cree Super Bright LED Light Bulb- Natural White” $58.99, ships and sold by EagleLight LEDs.
This appears to be the highest replacement wattage available. Pricing seems to be about one dollar per replacement wattage. I believe they need to reduce the cost by an order of magnitude (10) before these will become popular.
Did I read somewhere that CFL alter the power factor (which I dimly recall is to do with how AC current lags or leads the AC voltage) so that the power station has to make more power than the rating on the lamp? presumably lost in transmission.
If so, the saving in CO2 is less than one might think, and the hidden costs will go onto everyone’s bills…. icandescent – lamp users cross subsidising CFL users I suppose.
Don’t know about LED’s … anyone?