12 ms·

LED Bulbs Save Substantial Energy

51 points by raju 17y ago

Goronmon 17y ago
That was actually a much more detailed and thorough comparison than I had expected when I clicked the link.
pmjordan 17y ago
Now they just need to come down in price and get the spectrum right. While the fluorescent lights are already competitively priced, LED ones are still rather pricey, at about €15-20. The spectrum emitted by the pseudo-white LEDs is also unpleasant (primarily yellow + blue), the RGB ones need to become cheap enough. RGB lamps could also have some interesting extra features, like adjusting hue based on time of day, which might help insomniacs (such as myself).
- lsb 17y ago
  Or even RGB LED lighting that can plug into an Arduino, so you could make that yourself. Or, I suppose, in the vein of a plant that twitters about its thirst, a bot that performs sentiment analysis on your tweets and adjusts the light accordingly.
  - mixmax 17y ago
    We've done the RGB led --> Arduino --> Internet trick. This link will let you change the light color in the steering house of a barge in the Copenhagen harbour owned and run by artists and hackers. http://liljedahl.dk/christian/illutron/picker/ http://liljedahl.dk/christian/illutron/picker/ And this one lets you see how much power is currently being used on the barge. http://illutron.appspot.com/PowerGauge.html http://illutron.appspot.com/PowerGauge.html Were planning on doing more with this. Throw me an e-mail if anybody wants to play :-)
- dfox 17y ago
  RGB LEDs tend to have very unnatural spectrum with three narrow spikes, while normal white leds (blue led + some phosphor) has very wide spectrum (albeit different from incadescents, but probably better than common fluorescent lights). Other problem that I see with most RGB LED designs is that different colors are emitted from different spots, which tends to give unnatural shadows. Three years ago I built LED lamp out of some no-name high-power white LEDs (~1€/piece) and last year I got Phillips LivingColors lamp and subjectively I find the light given by bunch of no-name white LEDs more pleasant.
  - Devilboy 17y ago
    Really what you need to do is match the wavelenghts that our rods and cones in our eyes are most sensitive to. That should be the optimal solution in terms of energy usage.
    - eru 17y ago
      Perhaps. But it might not be pleasant to the eye.
      - pmjordan 17y ago
        The 'red' cones alone can't tell the difference between orange and brick red. The idea is to stimulate all 3 types of cones and the rods in the same proportion as daylight does. RGB LEDs should have the cones covered; I wonder if the problem are the rods? Do we need 4-component LEDs?
        eru 17y ago
        I don't know if all the cells in your eye are perfectly tuned to three peeks. I expect biological systems to show some variance.
        pmjordan 17y ago
        The mechanism is chemical/physical, though, and depends on the absorption spectrum of a certain pigment molecule for each type of receptor. I strongly suspect the variance in those is likely to be tiny.
- brc 17y ago
  V Australia (a new Australia-USA airline) planes have this feature. The lighting inside the plane varies depending on the time of 'day' they want you to think it is. They often ask to have the window shades closed to enhance the effect. The colours aren't completely natural - they range from a deep blue (daylight) to an orange (sunset/sunrise) to a purple-blue (nightime). It's all done gradually and very subtle. Subjectively it helped me to adjust to the different timezone during the flight, but it might have just been the 'hey, neato' factor as well.
- blahedo 17y ago
  They'll probably get there eventually, but considering that CFLs are only just now starting to become legit replacements for some incandescent bulbs---the light quality in a house that went all-CFL during the first big pushes a few years back is appalling---I wouldn't hold my breath.
  - pmjordan 17y ago
    Except with incandescent bulbs banned in the EU, there's now a strong economic incentive to build cheap, good and efficient replacements. Mind you, I'm not sure banning them outright is the way I'd have done it. (I'd have taxed the environmental impact per amount of light emitted and lifetime)
bumblebird 17y ago
We have a kitchen which contains about 7 small spotlights. I thought I'd try out some LED replacements, which each contain like 10 small white LEDs. They were more expensive, but I thought it'd be worth a try. A bit like these http://nextday.diy.com/app/jsp/product/productPage.jsp?productId=89946 http://nextday.diy.com/app/jsp/product/productPage.jsp?produ... The issue is, they look bright when you look at them, but they actually provide absolutely no actual light. Even when we had 7 of them, the room was almost pitch black. I actually think it's a bit of a con to even sell these things, knowing they are unusable for most applications. >> "While it is indisputable that LEDs use a fraction of the electricity of a regular bulb to create the same amount of light," I'm not sure on how they measure 'same amount of light', because all of the energy saving lights I've ever seen are absolutely no where near as bright as standard lights. Which is a shame. just my 2c
- amalcon 17y ago
  Most of the older LED spotlights are highly directional. Like, very highly. I suspect your bulbs did an excellent job of lighting one little spot on the floor beneath (or wall opposite) the light, and almost nothing to illuminate the whole room. Anyway, they've come a long way since then. Probably not long enough to buy them next time you change your bulbs, but they're a lot better than they used to be.
  - bumblebird 17y ago
    I bought these earlier this year :/ Maybe I'll give them another go in a few years.
    - amalcon 17y ago
      Well, nobody was buying the ones from a few years ago, so most of them are still on the market.
- wtallis 17y ago
  I've recently become a fan of the Black Diamond Apollo LED lanterns for camping use. They're only 3W, and the total light emitted isn't as high as from some of the competitors, but what makes them great is that the mirrors and lenses are shaped perfectly so that it evenly illuminates a tabletop-sized work area, and throws no light upwards. The focusing is easily the most important aspect of the product. However, it seems quite plausible that the different spectrum of LEDs could affect the perceived brightness, particularly if you're wanting the diffuse reflection from LED spotlights to act as ambient lighting.
bd 17y ago
Definitely. It's very noticeable when you are energy-constrained. I recently bought LED based flashlight and it's awesome. It's tiny, very bright and batteries lasts forever.
pxlpshr 17y ago
this is certainly a good thing, no doubt about it, but what I'd like to know is how many people's mindset shifts from conservative to liberal knowing that they are "saving electricity with new bulbs therefore can run the lights all day". i'd have to say i'd be in that camp as well because I work from home and often like it to be well-lit but force myself to act more conservatively in favor of our electricity bill. in my opinion, this was one of the problems with the American auto industry too. all of the efficiency realized through R&D effectively went into appeasing the "demand" for more HP instead of better MPG...
vinhboy 17y ago
tl;dr -- anyone have a link to the LED in the picture? it looks cool.
- jrockway 17y ago
  You probably would have scored higher and gotten a useful response if you had omitted the comment about your attention span.
tybris 17y ago
I recently replaced a bunch of 50W of Halogen lamps (came with the apartment) with 1W LEDs. It's quite a bit darker, but I got used to having more directed light. My energy bill dropped by about 70% without any other changes. It's interesting how quickly lighting costs can run up.
- brianobush 17y ago
  Can I ask what your costs were? How long do you estimate it will take to recoup your capital costs?
  - tybris 17y ago
    I'm not sure, but 1W LED lights shouldn't be more than $10 (mine were $7,50 iirc). I could say it took me 1 month, but that wouldn't be entirely fair since I have significantly reduced the lighting and changed the way I use it. Something which I probably would not have been able to do by, for example, reducing the number of lamps since that creates an annoying bright/dark distribution of light)
_ck_ 17y ago
No registration link http://google.com/search?hl=en&q=cache:www.nytimes.com%2F2009%2F11%2F30%2Fbusiness%2Fenergy-environment%2F30led.html http://google.com/search?hl=en&q=cache:www.nytimes.com%2...
mieses 17y ago
Incandescents approximate sunlight better than LED's and most other light sources. http://exploration.vanderbilt.edu/images/news/article_main/quantumdot_led_5.jpg http://exploration.vanderbilt.edu/images/news/article_main/q... The health implications should be studied. Subjectively, incandescents are more pleasant than fluorescents and LED's. Our brains might be telling us something.
- ardit33 17y ago
  I agree. For soft lights/ambient lights used with a dimmer, there is nothing yet to substitute the old incandescent. I did some shopping last night, and for my ambient light I decided to go with an incandescent. The extra energy cost is well worth it to me. Sorry environment.
  - eru 17y ago
    Just be sure to get the right color `temperature' for your energy saving lights. 5000K looks nicer and warmer than the `hotter' 8000K stuff, that you normally get.
- lowkey 17y ago
  Funny, I am a co-founder of a HW startup working in the LED space. One of our core patents is based on the concept of 'Polychromatic LED Light.' Our low-cost high-efficiency intelligent LED controls are designed to reproduce the full natural spectrum of lighting - more like natural sunlight than ever before possible. Incandescents do generate high quality light but they too fall short at reproducing natural sunlight. Unfortunately because Incandescents were dominant for so long the industry has established a color rendering index (CRI) based on a black-body radiator which considers incandescent to be perfect even though it actually falls far short. Fluorescents and Compact fluorescents produce horrible light as a result of the phosphor coating used to create white light. LEDs can be much better, though admittedly not all are. All in all LED lighting is the future for a whole host of reasons. I can't wait to replace fluorescents and CFL which, as a result of their mercury content, are one of the most environmentally toxic 'green technologies' ever developed. Just my, clearly biased, $0.02 :)
natch 17y ago
I was just at Home Depot this morning looking for LED 'bulbs' (using that term very loosely). Admittedly Home Depot might not be the best place to look. In any case, I was very disappointed. They are super dim compared to other choices. For $35 dollars you can get something with the physical size of a regular light bulb (which matters because I want to screw them into an existing fixture) but they only put out 200 lumens (!) as compared to 800 lumens for a 60-watt bulb or its ~15 watt compact fluorescent equivalent. Looking at the design of the unit, on the light-emitting side there was an enormous span of wasted black plastic, with fake plastic unneeded heat-dissipation fins taking a bunch of space, and with three LEDs arranged in the center. With better design, you could probably fit 12 or so LEDs in the same amount of space, and then it would be a product worth buying. Anyone know the story about why LEDs are not subsidized by state energy programs as CF bulbs are in California?
- brucer 17y ago
  here's some that go up to 1500 lumens: http://www.ledliquidatorsinc.com/PAR_38_12_LED_Cree_light_bulb.php http://www.ledliquidatorsinc.com/PAR_38_12_LED_Cree_light_bu... one thing to note is with LED's the higher power ones are less efficient, so the 800 lumen lights on that page use 1/3 the power.
dnsworks 17y ago
I'm personally hedging my bets on light bulbs until the replacement compromises go away. CFLs don't last nearly as long as Incandescents, and the light they cast is subpar. It is silly to spend hundreds of dollars to replace a tried and true, centuries old technology with vaporware because of effective guilt-based "green marketing".
brc 17y ago
I recently fitted all new lighting in my home. I looked at LED lighting, but the salesman was quite honest with me and said that at this point, unless you double the amount of fittings, you're going to be dissapointed. It's not so much the light output but rather the angle of the light - you end up with little star trek beams all over the place. I bought some CFL spotlights and fitted them into the bathrooms, but I don't like the light quality - it reminds me of an airline toilet. I fitted plain 'ol inefficient halogens to the kitchen, and it's by far the most pleasant lighting in the house. CFL replacements went into all the other fittings. I haven't noticed any difference in my power bills at all. I suspect that might be to do with the 13 kw air conditioner, pool pump, at least 6 computers running, plasma tv, tivo, exhaust and ventilation fans and exterior lighting. Interior lighting is such a small part of the total energy use in a lot of modern houses.
anamax 17y ago
Their CFL lifetime numbers don't match my experience. (I typically get longer life from incandescents than CFLs.) Also, they assume that energy converted to heat is wasted. If you're heating a lit room, that's obviously not true. Yes, many forms of heat are cheaper than resistive, but if you're going to claim to be the last word, you have to account for things like that.
- jackmoore 17y ago
  Heat generated by a lightbulb is near the ceiling where air is probably not being well circulated. So unless you are installing fans around the base of your bulbs to move the warm air around the room where it would be useful to the inhabitants, it is mostly wasted. This is assuming that the heat is even desirable.
  - teeja 17y ago
    Air circulation is essential to efficient and comfortable heating with any heat source. However it's done, it must be or heat will pool at the ceiling. You're right if lighting is done at ceiling level. Table lamps, though, create some convected air.

51 points by raju 17y ago

That was actually a much more detailed and thorough comparison than I had expected when I clicked the link.

Now they just need to come down in price and get the spectrum right. While the fluorescent lights are already competitively priced, LED ones are still rather pricey, at about €15-20. The spectrum emitted by the pseudo-white LEDs is also unpleasant (primarily yellow + blue), the RGB ones need to become cheap enough. RGB lamps could also have some interesting extra features, like adjusting hue based on time of day, which might help insomniacs (such as myself).

lsb 17y ago
Or even RGB LED lighting that can plug into an Arduino, so you could make that yourself. Or, I suppose, in the vein of a plant that twitters about its thirst, a bot that performs sentiment analysis on your tweets and adjusts the light accordingly.
- mixmax 17y ago
  We've done the RGB led --> Arduino --> Internet trick. This link will let you change the light color in the steering house of a barge in the Copenhagen harbour owned and run by artists and hackers. http://liljedahl.dk/christian/illutron/picker/ http://liljedahl.dk/christian/illutron/picker/ And this one lets you see how much power is currently being used on the barge. http://illutron.appspot.com/PowerGauge.html http://illutron.appspot.com/PowerGauge.html Were planning on doing more with this. Throw me an e-mail if anybody wants to play :-)
dfox 17y ago
RGB LEDs tend to have very unnatural spectrum with three narrow spikes, while normal white leds (blue led + some phosphor) has very wide spectrum (albeit different from incadescents, but probably better than common fluorescent lights). Other problem that I see with most RGB LED designs is that different colors are emitted from different spots, which tends to give unnatural shadows. Three years ago I built LED lamp out of some no-name high-power white LEDs (~1€/piece) and last year I got Phillips LivingColors lamp and subjectively I find the light given by bunch of no-name white LEDs more pleasant.
- Devilboy 17y ago
  Really what you need to do is match the wavelenghts that our rods and cones in our eyes are most sensitive to. That should be the optimal solution in terms of energy usage.
  - eru 17y ago
    Perhaps. But it might not be pleasant to the eye.
    - pmjordan 17y ago
      The 'red' cones alone can't tell the difference between orange and brick red. The idea is to stimulate all 3 types of cones and the rods in the same proportion as daylight does. RGB LEDs should have the cones covered; I wonder if the problem are the rods? Do we need 4-component LEDs?
      - eru 17y ago
        I don't know if all the cells in your eye are perfectly tuned to three peeks. I expect biological systems to show some variance.
        pmjordan 17y ago
        The mechanism is chemical/physical, though, and depends on the absorption spectrum of a certain pigment molecule for each type of receptor. I strongly suspect the variance in those is likely to be tiny.
brc 17y ago
V Australia (a new Australia-USA airline) planes have this feature. The lighting inside the plane varies depending on the time of 'day' they want you to think it is. They often ask to have the window shades closed to enhance the effect. The colours aren't completely natural - they range from a deep blue (daylight) to an orange (sunset/sunrise) to a purple-blue (nightime). It's all done gradually and very subtle. Subjectively it helped me to adjust to the different timezone during the flight, but it might have just been the 'hey, neato' factor as well.
blahedo 17y ago
They'll probably get there eventually, but considering that CFLs are only just now starting to become legit replacements for some incandescent bulbs---the light quality in a house that went all-CFL during the first big pushes a few years back is appalling---I wouldn't hold my breath.
- pmjordan 17y ago
  Except with incandescent bulbs banned in the EU, there's now a strong economic incentive to build cheap, good and efficient replacements. Mind you, I'm not sure banning them outright is the way I'd have done it. (I'd have taxed the environmental impact per amount of light emitted and lifetime)

bumblebird 17y ago

We have a kitchen which contains about 7 small spotlights. I thought I'd try out some LED replacements, which each contain like 10 small white LEDs. They were more expensive, but I thought it'd be worth a try. A bit like these http://nextday.diy.com/app/jsp/product/productPage.jsp?productId=89946 http://nextday.diy.com/app/jsp/product/productPage.jsp?produ... The issue is, they look bright when you look at them, but they actually provide absolutely no actual light. Even when we had 7 of them, the room was almost pitch black. I actually think it's a bit of a con to even sell these things, knowing they are unusable for most applications. >> "While it is indisputable that LEDs use a fraction of the electricity of a regular bulb to create the same amount of light," I'm not sure on how they measure 'same amount of light', because all of the energy saving lights I've ever seen are absolutely no where near as bright as standard lights. Which is a shame. just my 2c

amalcon 17y ago
Most of the older LED spotlights are highly directional. Like, very highly. I suspect your bulbs did an excellent job of lighting one little spot on the floor beneath (or wall opposite) the light, and almost nothing to illuminate the whole room. Anyway, they've come a long way since then. Probably not long enough to buy them next time you change your bulbs, but they're a lot better than they used to be.
- bumblebird 17y ago
  I bought these earlier this year :/ Maybe I'll give them another go in a few years.
  - amalcon 17y ago
    Well, nobody was buying the ones from a few years ago, so most of them are still on the market.
wtallis 17y ago
I've recently become a fan of the Black Diamond Apollo LED lanterns for camping use. They're only 3W, and the total light emitted isn't as high as from some of the competitors, but what makes them great is that the mirrors and lenses are shaped perfectly so that it evenly illuminates a tabletop-sized work area, and throws no light upwards. The focusing is easily the most important aspect of the product. However, it seems quite plausible that the different spectrum of LEDs could affect the perceived brightness, particularly if you're wanting the diffuse reflection from LED spotlights to act as ambient lighting.

bd 17y ago

Definitely. It's very noticeable when you are energy-constrained. I recently bought LED based flashlight and it's awesome. It's tiny, very bright and batteries lasts forever.

pxlpshr 17y ago

this is certainly a good thing, no doubt about it, but what I'd like to know is how many people's mindset shifts from conservative to liberal knowing that they are "saving electricity with new bulbs therefore can run the lights all day". i'd have to say i'd be in that camp as well because I work from home and often like it to be well-lit but force myself to act more conservatively in favor of our electricity bill. in my opinion, this was one of the problems with the American auto industry too. all of the efficiency realized through R&D effectively went into appeasing the "demand" for more HP instead of better MPG...

vinhboy 17y ago

tl;dr -- anyone have a link to the LED in the picture? it looks cool.

jrockway 17y ago
You probably would have scored higher and gotten a useful response if you had omitted the comment about your attention span.

tybris 17y ago

I recently replaced a bunch of 50W of Halogen lamps (came with the apartment) with 1W LEDs. It's quite a bit darker, but I got used to having more directed light. My energy bill dropped by about 70% without any other changes. It's interesting how quickly lighting costs can run up.

brianobush 17y ago
Can I ask what your costs were? How long do you estimate it will take to recoup your capital costs?
- tybris 17y ago
  I'm not sure, but 1W LED lights shouldn't be more than $10 (mine were $7,50 iirc). I could say it took me 1 month, but that wouldn't be entirely fair since I have significantly reduced the lighting and changed the way I use it. Something which I probably would not have been able to do by, for example, reducing the number of lamps since that creates an annoying bright/dark distribution of light)

_ck_ 17y ago

No registration link http://google.com/search?hl=en&q=cache:www.nytimes.com%2F2009%2F11%2F30%2Fbusiness%2Fenergy-environment%2F30led.html http://google.com/search?hl=en&q=cache:www.nytimes.com%2...

mieses 17y ago

Incandescents approximate sunlight better than LED's and most other light sources. http://exploration.vanderbilt.edu/images/news/article_main/quantumdot_led_5.jpg http://exploration.vanderbilt.edu/images/news/article_main/q... The health implications should be studied. Subjectively, incandescents are more pleasant than fluorescents and LED's. Our brains might be telling us something.

ardit33 17y ago
I agree. For soft lights/ambient lights used with a dimmer, there is nothing yet to substitute the old incandescent. I did some shopping last night, and for my ambient light I decided to go with an incandescent. The extra energy cost is well worth it to me. Sorry environment.
- eru 17y ago
  Just be sure to get the right color `temperature' for your energy saving lights. 5000K looks nicer and warmer than the `hotter' 8000K stuff, that you normally get.
lowkey 17y ago
Funny, I am a co-founder of a HW startup working in the LED space. One of our core patents is based on the concept of 'Polychromatic LED Light.' Our low-cost high-efficiency intelligent LED controls are designed to reproduce the full natural spectrum of lighting - more like natural sunlight than ever before possible. Incandescents do generate high quality light but they too fall short at reproducing natural sunlight. Unfortunately because Incandescents were dominant for so long the industry has established a color rendering index (CRI) based on a black-body radiator which considers incandescent to be perfect even though it actually falls far short. Fluorescents and Compact fluorescents produce horrible light as a result of the phosphor coating used to create white light. LEDs can be much better, though admittedly not all are. All in all LED lighting is the future for a whole host of reasons. I can't wait to replace fluorescents and CFL which, as a result of their mercury content, are one of the most environmentally toxic 'green technologies' ever developed. Just my, clearly biased, $0.02 :)

natch 17y ago

I was just at Home Depot this morning looking for LED 'bulbs' (using that term very loosely). Admittedly Home Depot might not be the best place to look. In any case, I was very disappointed. They are super dim compared to other choices. For $35 dollars you can get something with the physical size of a regular light bulb (which matters because I want to screw them into an existing fixture) but they only put out 200 lumens (!) as compared to 800 lumens for a 60-watt bulb or its ~15 watt compact fluorescent equivalent. Looking at the design of the unit, on the light-emitting side there was an enormous span of wasted black plastic, with fake plastic unneeded heat-dissipation fins taking a bunch of space, and with three LEDs arranged in the center. With better design, you could probably fit 12 or so LEDs in the same amount of space, and then it would be a product worth buying. Anyone know the story about why LEDs are not subsidized by state energy programs as CF bulbs are in California?

brucer 17y ago
here's some that go up to 1500 lumens: http://www.ledliquidatorsinc.com/PAR_38_12_LED_Cree_light_bulb.php http://www.ledliquidatorsinc.com/PAR_38_12_LED_Cree_light_bu... one thing to note is with LED's the higher power ones are less efficient, so the 800 lumen lights on that page use 1/3 the power.

dnsworks 17y ago

I'm personally hedging my bets on light bulbs until the replacement compromises go away. CFLs don't last nearly as long as Incandescents, and the light they cast is subpar. It is silly to spend hundreds of dollars to replace a tried and true, centuries old technology with vaporware because of effective guilt-based "green marketing".

brc 17y ago

I recently fitted all new lighting in my home. I looked at LED lighting, but the salesman was quite honest with me and said that at this point, unless you double the amount of fittings, you're going to be dissapointed. It's not so much the light output but rather the angle of the light - you end up with little star trek beams all over the place. I bought some CFL spotlights and fitted them into the bathrooms, but I don't like the light quality - it reminds me of an airline toilet. I fitted plain 'ol inefficient halogens to the kitchen, and it's by far the most pleasant lighting in the house. CFL replacements went into all the other fittings. I haven't noticed any difference in my power bills at all. I suspect that might be to do with the 13 kw air conditioner, pool pump, at least 6 computers running, plasma tv, tivo, exhaust and ventilation fans and exterior lighting. Interior lighting is such a small part of the total energy use in a lot of modern houses.

anamax 17y ago

Their CFL lifetime numbers don't match my experience. (I typically get longer life from incandescents than CFLs.) Also, they assume that energy converted to heat is wasted. If you're heating a lit room, that's obviously not true. Yes, many forms of heat are cheaper than resistive, but if you're going to claim to be the last word, you have to account for things like that.

jackmoore 17y ago
Heat generated by a lightbulb is near the ceiling where air is probably not being well circulated. So unless you are installing fans around the base of your bulbs to move the warm air around the room where it would be useful to the inhabitants, it is mostly wasted. This is assuming that the heat is even desirable.
- teeja 17y ago
  Air circulation is essential to efficient and comfortable heating with any heat source. However it's done, it must be or heat will pool at the ceiling. You're right if lighting is done at ceiling level. Table lamps, though, create some convected air.