LED Bulbs Save Substantial Energy | Hacker News Reader

LED Bulbs Save Substantial Energy

nytimes.com

51 pointsraju47 comments

Incandescents approximate sunlight better than LED's and most other light sources.

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.

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.

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.

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 :)

"Fluorescents and Compact fluorescents produce horrible light as a result of the phosphor coating used to create white light." That's a bit of an overgeneralisation -- there's a significant difference between the cheapo tubes and, say, an OTT tube (just one, albeit excellent, example of a full-spectrum fluorescent).

The easiest, cheapest way to get a decent idea of the spectrum is to use a CD or DVD (we've all got at least one coaster at home that used to be a disk). The data side makes a great diffraction spectrometer. A common industrial-grade tube has great gaping holes in the spectrum; an OTT is indistinguishable from indirect skylight (the 6500K "north light" of the studio artist's dream). It's a bit disconcerting at first, probably because we're very much used to incandescent light indoors ("daylight" photographic incandescents might hit 4200K when they're brand new, and they're WAY blue compared to standard bulbs at around 2500-2800K) but it can hardly be described as "horrible".

LEDs aren't quite there yet -- at least none of the ones I've actually seen are. On the other hand, I fondly remember a time when LEDs could not be seen at all outdoors in daylight and drank power at a rate that would have left a plasma TV in an envious rage -- one had to duck into the shade and press eighteen or so buttons simultaneously in order to tell time on a thousand-dollar digital watch. The idea of using an LED (other than a laser) to illuminate anything other than itself was laughable around 1980; the spectrum problem and diffusion are trivial compared to the problems that have already been solved. It won't be long.

Thank you very much for the CD/DVD idea! I see five clear differently-colored copies of my local compact florescent tube in my DVD's rainbow... can you confirm that I am interpreting that correctly as five spikes and virtually nothing in between those spikes?

My local incandescent lights are just a rainbow smear.

Oh, awesome, I can do it to my LCD screen too and clearly see three differently-colored reflections!

...

Forgive my geekout, but that's cool and I've never heard it before.

Why, yes. Yes I can confirm that. And I can tell you that noticing it about 25 years back, when I was doing photography professionally, saved me a metric crapload of money on special meters and so on -- but only after I had button-holed every single person I'd ever met to show them what I'd seen whether they cared or not. I truly understand the geek-out part.

How does this work with a lampshade or a wall sconce? Putting the light through some kind of filter must (?) narrow the difference between the kinds of light. In which case I've got a lot of lights that can be upgraded to LED.

I'm willing to pay the high initial cost of LED lighting, assuming the light is of good quality (brightness AND color-with-lampshade) and the long-term savings are real. I suspect most HN readers come to the same conclusion.

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?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

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.

I bought these earlier this year :/ Maybe I'll give them another go in a few years.

Well, nobody was buying the ones from a few years ago, so most of them are still on the market.

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.

Even the expensive $200 LED light that would go in my kitchen is only 750 lumens. http://www.bulbs.com/eSpec.aspx?ID=15695&Ref=LED+Bulbs&#...

The halogens are $7 and 1280 lumens. No contest really. Especially when I have 6 of them.

What I've noticed in looking at LED bulbs is that the packaging never lists an "equivalent wattage", the way CFLs will say something like "13W (equivalent to 60W incandescent)". They also are often labeled "accent bulbs".

I have only been following LED indoor lighting as a non-participant, but from what I've read, you need to stick with name-brand at this point.

Cree has popped up a number of times in technical articles as a leader in white LEDs. Their product focus is on recessed lighting:

http://www.creeledlighting.com/residential.htm

The photo in the NY Times article is of Philips' entry into the L Prize. Time Magazine has a short blurb on the bulb, albeit light on information (pun not intended):

http://www.time.com/time/specials/packages/article/0,28804,1...

My best guess is that 2010 will be a good year to start dipping your toes in LED lights for around the house. If I owned my own house, I would probably get the Cree recessed lights today. I enjoy a well lit house, and turning lights on and off to save energy annoys me. I welcome the day that I have my own solar panels, LED lights, and solar tube lighting.

There was a very good article recently in either LED Journal (yes, there are publications dedicated to LEDs exclusively) or Electronic Design that discussed this. The problem is so many low quality manufacturers are churning out these cheap "incandescent replacements" that do little good that they are making consumers think that LEDs are a scam.

There are very good LED lamps out there, built with high efficiency, high brightness LEDs, but they are expensive.

It really is a pity. I've been experimenting with multiwatt LEDs for some time (individual, unpackaged units) for a little off-grid experiment I have going and they are scary bright! But at the consumer level, there is nothing available at low cost that is useful.

The only LED light sources in my house, besides the LEDs on some electronics, is this lamp: http://www.konceptech.com/Merchant2/merchant.mv?Screen=PROD&...

And a camping headlight.

I consider these two things to be of the coolest things I own. They definitely show off proper LED application.

For the camping headlight, which wasn't very cheap, I don't have to worry about disrupting the darkness too much. And the batteries will last forever.

For the lamp, same thing. It is a wonderful feeling staying up till 5 in the morning with nothing but you, the lamp, and your work. Nothing but the desk and your work is illuminated, and it is illuminated very pleasantly, which is awesome.

So, depending on the application, those negatives are strong positives. I can't imagine the LEDs being used as household lighting.

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).

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.

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/

And this one lets you see how much power is currently being used on the barge. http://illutron.appspot.com/PowerGauge.html

Were planning on doing more with this. Throw me an e-mail if anybody wants to play :-)

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.

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.

Perhaps. But it might not be pleasant to the eye.

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?

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.

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.

The fact that you can see a full spectrum -- as in a rainbow, thin-film refraction on a puddle on a paved street, etc. -- should be an indication that the band-pass for neural firing is relatively wide. If each optical receptor had a narrow acceptance window (the way that individual atoms absorb), there would be gaps in the rainbow. Remember that ALL of the colours you see in a rainbow are pure, composed entirely of photons of a particular wavelength proper to each of those colours. It's not RGB; it's not CMYK.

We can, to an extent, simulate a full spectrum through additive and subtractive colour mixing of "primaries", but it is only a simulation. (And Edwin Land demonstrated that we don't actually need all three of R, G and B in order to create the illusion of a full-colour picture with only a comparatively tiny gamut loss. It is a fragile thing, though, and requires the integrative function and cognitive mapping of our brains.

Similarly, we can easily tell the difference between full-spectrum lighting and discontinuous spectrum lighting. Discontinuous spectrum lighting makes us uncomfortable. None of the colours looks quite right. Food is unappetizing, pictures and people less attractive. Did the light-makers just miss the right mix of frequencies by a hair? No -- any scheme that relies on a small number of discreet wwavelengths will cause a similar discomfort. We may not know why we feels the way we feel at the time, but we sho' 'nuff knows we'se feelin' it.

You make a good point - I forgot about indirect light and banded spectra interacting with surfaces.

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.

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.

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)

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

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.

Can I ask what your costs were? How long do you estimate it will take to recoup your capital costs?

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)

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...

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?

here's some that go up to 1500 lumens: 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.

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.

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.

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.

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.

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.

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".

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

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

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