Should I buy LED or CFL light bulbs?

http://www.mnn.com/earth-matters/energy/stories/should-i-buy-led-or-cfl-light-bulbs

by MikeCapone • 13 years ago

24 57 13 years ago

dorfsmay• 13 years ago

To add to the list, my experience is that half of the CFLs I have been using die way earlier than expected, which has not been the case with LEDs. Also, you cannot use regular CFLs outside in cold countries (-20C), and the special one that are supposed to work in cold temp. are as expensive as LEDs.

At this point I find that the LEDs are cheap enough to be worth buying, one to avoid the pain point of CFLs (slow start, fragile, early death), and two to support the industry into the next generation.

trafficlight2• 13 years ago

I also hate the hum of fluorescent ballasts and the cheaper CFLs, in my experience, have a louder hum that I drives me insane.

ars3• 13 years ago

Fluorescents and CFLs have not hummed in about a decade - just how old are your bulbs?

programminggeek• 13 years ago

So it looks like in terms of cost, LED is now to the point where it is the smart buy if you consider your time valuable at all (how much time do you want to spend changing light bulbs?). The energy expenditure might be the same between CFL and LED, but if you figure you need to change a CFL 3x as often, that's 3 times the lightbulb changing events.

Also, it seems like we are reaching diminishing returns outside of potential manufacturing efficiencies at some point in the future. How far can we go to make lighting efficient until it makes more sense to focus on other areas of energy consumption like the systems that manage your lighting or other home/office utility infrastructure like the Nest thermostat?

ruswick2• 13 years ago

Unless there is some sort of significant impediment to changing a bulb (eg. a covered fixture), it takes 30 seconds to a minute maximum to change a bulb. It will probably take everyone reading this more time to read the article and participate in this thread than it will to change every light bulb in their house for the next decade. It's negligible.

There are many things to take into account when purchasing bulbs; chance are, the time it takes to change them is not one.

seiji• 13 years ago

Counterpoints: ceiling fans in high places (like, ceilings), flood lights at the corner of a three story house, sealed in-ground lights, ...

acurious1ne• 13 years ago

LED if you can afford them, CFL if not. There's little difference in their luminous efficacy (aka efficiency) at this point. CFLs have a small amount of mercury in them, so if product neurotoxicity matters to you, go LED.

Edvik• 13 years ago

How far have LEDs come in terms of looking pleasant in terms of light quality? There's wildly different anecdotal data on how well people respond even to the highest quality CRI. Looking at spectroradiometer charts even bulbs rated 95+ CRI have very narrow spikes compared to a blackbody radiator.

tghw• 13 years ago

I have Cree LED bulbs throughout my house. I've been very happy with their quality of light. I haven't done any in depth analysis, but being a photographer, I've come to notice light quality, and these are similar to most incandescent bulbs.

ollysb• 13 years ago

I moved into an apartment not too long ago that was full of CFLs. For me I found the quality of the light incredibly bad, a bit like being under office strip lighting but not as bright. I replaced them all with Philips LED bulbs and am extremely happy with the quality of the light. The light is more bluey than a tungsten bulb but apart from that I found them to be the best bulbs of any type that I've ever had.

snogglethorpe• 13 years ago

Looking at spectroradiometer charts even bulbs rated 95+ CRI have very narrow spikes compared to a blackbody radiator.

Are you sure you're not looking at SPDs for CFLs instead?

LED lightbulbs at least typically seem to have relatively broad and even spectral coverage, even if the distribution is a little lumpy and only a rough approximation of a BB.

All the SPDs of CFLs I've seen on other other hand, are vastly worse, with lots of super intense and narrow spikes in the middle of large areas of almost nothing.

In other words, CFL SPDs look nothing like a BB SPD, whereas LEDs can kinda-sorta-come-close-if-you-squint (it depends on the particular bulb, but some are not bad at all).

[LED lighting also seems much more likely to improve significantly in the future, as it's been developed for a much shorter time than florescent lighting.]

bhauer3• 13 years ago

In terms of CRI, I have not yet found a line of LED bulbs that can accomplish the same color accuracy I've come to enjoy from my high-CRI fluorescent bulbs. CREE and SORAA are among the best, as far as I can tell. But I am a layperson when it comes to illumination. I have also decided to concede high-CRI as long as I can retain the high color temperature that I prefer (I prefer 5000K interior illumination even in the evening, which I understand is uncommon).

I'm not running a lab or anything where CRI is critical. I had simply preferred high-CRI when I was given the luxury of opting for that when I switched my house from incandescent to fluorescent ten years ago. I would like to see better CRI in LED, but to-date it doesn't seem to be a focus, even amount the high-end brands.

nickhalfasleep• 13 years ago

This is a status report from the awesome work the DOE is doing to map the state of the art in lighting technology and continue to provide incentives to the industry to keep advancing standards, efficiency, and quality in what it takes to get an energy star label. This is from a wide range of samples in 2011, things only get better from here.

The DOE knows they didn't do so hot with CFLs and anybody you talk to will complain about them. They are not making the same mistake twice, and reports like this, as well and monitoring programs like CALIPER (http://www1.eere.energy.gov/buildings/ssl/caliper.html) provide great independent data for consumers to read if they want real numbers.

You have to realize that any CFL plant is just being run out to try and squeeze every last cent from the facility before it gets shut down, so the quality is going to drop as companies lose interest in them. If you buy from a reputable company (Philips, Cree, GE, etc.. etc..) you'll do much better than these averages.

(I used to be in the lighting industry)

greenyoda2• 13 years ago

"We already know that incandescent light-bulbs are on the way out because they're incredibly wasteful, being better at producing heat than light."

In climates like the northeast U.S., the heat that incandescent bulbs generate isn't wasted for most of the year: it helps heat your house, which means you burn slightly less oil or gas in your furnace. They're only wasteful during the summer months. And a CFL probably takes more energy to manufacture and recycle, and needs more packaging material to prevent breakage, since nobody likes to clean up toxic mercury spills. (After having read the dire warnings on the EPA's web site about what procedure to follow if you break a CFL, I never wanted buy another CFL again.)

ericd4• 13 years ago

Interesting point, but that's mainly true if you use resistive electric heating. Heat pumps are much more efficient than turning electricity directly into heat unless it's extremely cold.

greenyoda2• 13 years ago

But if you're using both the light and the heat generated by the light bulb, aren't you making use of almost 100% of the energy that's being consumed?

stephengillie2• 13 years ago

Last week I learned that x86 (and x86-64) PCs & servers are basically resistance heaters. So it's almost as efficient to heat your house by rackmount as it is by incandescent?

mrbabbage• 13 years ago

Incandescents release more mercury into the enviroment over the course of their lifetime because they use more electricity, since much electricity is based on coal mining (which inevitably releases some mercury). [1]

Also, if you're concerned about CFL taking more energy to manufacture and recycle, also consider the fact that a typical CFL lasts the lifetime of multiple incandescent bulbs.

(Note: I'm not trying to make any particular point other than the only valid way to compare two technogies is with a proper cradle to grave analysis)

[1] http://www.nrdc.org/legislation/files/lightbulbmercury.pdf

hrjet• 13 years ago

Look at it this way:

If electricity was cheaper than oil/gas, then you wouldn't use an oil/gas furnace to begin with.

So, an efficient lighting system is saving you money.

coin2• 13 years ago

Yup, my house is heated using an electric furnace (resistive heat). Thus the heat from incandescent lightbulbs doesn't go to waste during the winter.

fspeech• 13 years ago

To second hrjet, think of it this way: electricity has to be produced from another source of primary energy, the efficiency of which is very much less than one. So even if electricity can be converted into heat 100% efficiently you are still better off producing heat from the primary source directly, ignoring the cost of distribution. In general the price you pay should reflect the utility of the resource consumed.

munger• 13 years ago

One major thing no one ever seems to mention or realize about CFL bulbs is that if you read the fine print on the packaging, the life expectancy is based on leaving the bulb on for long periods of time like 3 hours per day continuous.

They have warnings along the lines of that damp environments like bathrooms, and turning them off quickly (less than 20-30 minutes on) significantly decreases the life of the bulb.

So if you plan to use CFLs that will be turned on and off quickly like bedrooms, bathrooms, hall lights, etc - basically everywhere except the living room / reading light that you plan to have on for hours at a time - CFLs will die faster than an incandescent - within 12-18 months of light use. You basically get punished for being good at turning off lights when not in use.

hcarvalhoalves3• 13 years ago

It's not only turning on/off that wears it out. CFLs lose efficiency over time anyway, down to 80-70% of the light output in as soon as 6 months. After a year or two they can be below 50%. Tri-phosphorous ones stay efficient for longer, but are harder to find, usually labeled for professional applications, and cost more.

If I'm not mistaken, LEDs being solid state don't lose efficiency over time like that, so it's always working at peak output as long as the driver lasts. That alone should make it more cost effective.

ars3• 13 years ago

If I'm not mistaken, LEDs being solid state don't lose efficiency over time

You are mistaken, LEDs most definitely do lose efficiency.

http://web.archive.org/web/20090410145015/http://www1.eere.e...

LEDs and CFLs are about the same as far as losing efficiency.

coin2• 13 years ago

Is it the phosphors that wear out? If so, many LED bulbs uses phosphors, make it also a form of fluorescence bulb.

tanzam753• 13 years ago

No. In fact, the LED lifetime stated on the packaging is actually the time it takes to decrease in brightness to a specified reference level -- usually 70% of initial brightness.

Since it is solid-state, though, the LED is expected to continue operating long after it reaches 70% brightness. 70% is simply the assumed reference point at which the consumer becomes annoyed and decides to replace the LED.

Source: Department of Energy, "Lifetime of White LEDs", http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl...

the Alliance for Solid State Illumination Systems and Technologies (ASSIST), a group led by the Lighting Research Center (LRC), recommends defining useful life as the point at which light output has declined to 70% of initial lumens (abbreviated as L70) for general lighting and 50% (L50) for LEDs used for decorative purposes.

nfailor• 13 years ago

all I need to be happy is a bright set of color changing LED bulbs--you're lying to yourself if you think otherwise.

ruswick2• 13 years ago

One thing to note is that CFLs take time to "warm up," which is significantly irritating to ensure that I don't use them in most cases.

dewarrn1• 13 years ago

I had the same reaction at first, but then recognized (possibly after reading someone's Slashdot or HN post) that the slowly increasing output is actually quite welcome in some circumstances (e.g., late at night, first thing in the morning). It's not a feature that I'd request, but I don't mind the tradeoff now.

ctdonath• 13 years ago

Rumors persist about interference between LED bulbs and WiFi networks. Any HNish insights?

bhauer3• 13 years ago

I've got several LED bulbs in my household and I've not noticed any WiFi connectivity problems or degradation. Sorry I can't give you anything aside from this anecdote. This is the first I've heard of any possible interference.

droidist2• 13 years ago

I've been wondering the same thing. One question I have: Will LEDs over my bathroom mirror bruise my self esteem as much as the harsh CFLs do?

Seeing a close-up of yourself with CFL complexion when you first wake up and brush your teeth, when you get out of the shower, before you leave the house... it subtly takes its toll after a while.

jpollock2• 13 years ago

I'm confused. The story talks about manufacturing and transport. However, I don't care about that.

As a consumer, I want to know $/lumen. That's it.

The last time I looked, the energy savings for LED were swamped by the upfront purchase costs. CFLs were still significantly cheaper.

Of course, that's for NZ, and the US might be different.

NZ Prices from Consumers NZ (Bulb + Running over 5 years)

Incandescent: $115 CFL: $30 LED: $95 (60W equiv), or $57 (40W equiv)

tanzam753• 13 years ago

What year are the numbers from? I have a hard time believing that New Zealand pays 3x as much for its LEDs as the United States does.

800-lumen LEDs are already down to $15-20 unsubsidized in the United States. Some utilities also provide a subsidy for each LED.

Granted, the 10-watt LED does not save you much in power costs over the 13-watt CFL of equivalent brightness. However, the LED is already cheap enough to be a viable replacement for incandescents in bathrooms, and other areas where high cycling rates will kill CFLs.

jpollock2• 13 years ago

Those numbers are NZD, and from less than 2 months ago. :) To convert to USD, multiply by 0.8.

I just looked on the home hardware website, and they don't sell any MR16s that are more than 6.5W. The 12W bulb is a 650 lumen and sells for NZ$13. However, a CFL goes for less than NZ$4. That $9 will buy you a lot of electricity.

At 3hrs/day, and NZ$0.25/kwh, that's a break even point of ~5.5 years... I think... (6W difference in power usage between CFL and LED?)

Going from a 20W halogen to a 10W led would result in a payback period of 3 years. To me, these sorts of things need to pay off in their warranty period. :)

ars3• 13 years ago

one by Philips that gets 200 lumens/watt.

The absolute theoretical max for efficiency is 251 lumens/watt. I find it incredibly unlikely that they are going to reach 200 with white light.

What I think will happen is they'll get there by having a very low CRI, with off-color light. It's already happening in the market - all the high efficiency bulbs have a CRI of 80 (the minimum needed to get an Energy Star rating). But the CFLs they are compared against often have a CRI of 90.

ableal• 13 years ago

They linked the article that mentioned that 200 lumens/watt lamp ( http://www.treehugger.com/energy-efficiency/philips-shows-br... ), seems a replacement for fluorescent tubes.

Quote from that: "[...] this new LED model achieves an impressive 200 lumens/watt while meeting the criteria required for comfortable workplace lighting (ie. a color temperature of 3000–4000 kelvins, a color rendering index of at least 80, and an R9 saturated red level of no less than 20). That's not the same as having a super-efficient LED that produces horrible light quality for the sake of breaking records."

Also: "expected to hit the market in 2015 for office and industry applications".

MichaelGG• 13 years ago

Are there good CFL or LED bulbs with proper color temp? I end up using halogen bulbs in every room in my house because I've not been able to find anything that's remotely as nice.

rhizome2• 13 years ago

I don't know the term associated with them, but I have bought CFLs that have a more incadescent-like yellow cast than the usual prison-hallway colored ones.

stephengillie2• 13 years ago

How much would the light be dimmed by putting a shade of some sort over the LED lamp?

Daniel_Newby• 13 years ago

Yes. The whole range is available. I have a 2700 K LED bulb for the kitchen night light, and a bunch of 6800 K CFLs on a timer for my wake up light. Lowes hardware stores have a live demonstration of several color temperatures.

thomas• 13 years ago

Great comments here, and interesting article. If anyone is interested, here is a book on LED lighting: http://www.amazon.com/LED-Lighting-Primer-Future/dp/14493347...

covers all the basics - CFL lifespan, lumen depreciation, etc.

a3n• 13 years ago

Here's a four page pdf from the EPA on what to do if a CFL breaks. http://www2.epa.gov/sites/production/files/documents/cflclea...

It's not always about efficiency.

mmagin• 13 years ago

With regard to bulb life, the big thing to remember about both CFL and LED drop-in replacements for incandescent bulbs is that the electronics do not tolerate high temperatures well, so they're not particularly suitable for use in completely closed fixtures.

Where practical, both for heat dissipation and optical purposes, it's far more ideal to use fixtures which are actually designed around these technologies rather than just throwing retrofit bulbs into crappy incandescent fixtures.

I'm really hoping we see more of these sold to the consumer markets. For good quality LED products, you're talking about 50k hour life which makes a non-user-replaceable solution not seem that bad -- some cheap incandescent bulb sockets might start having trouble after equivalent usage.

On the other hand, I'm concerned that we're going to see a repeat of all the cheap low quality products we've seen in CFL-land.

bhauer3• 13 years ago

Interesting that you should point this out because I converted my home to full ~5000K high-CRI fluorescent in 2003 and now ten years later, I am about a third of the way through replacing all fluorescent bulbs in my household with ~5000K LED bulbs.

I recently tackled the challenge of equipping an enclosed light fixture with an LED bulb. I ended up going with the Xledia D series A19 bulb. (Warning, Xledia is a Chinese company and I think they've hired a gray-hat SEO company to spam up Twitter and the like; but don't let that taint whatever merits they have in engineering.)

The D125 [1] is my favorite LED bulb to-date. My wife, an electrical engineer, was incredulous: "you bought a seventeen watt LED bulb??" It's quite astonishing to fire that beast up. 2000 lumens. And true to its spammy marketing ("the most efficient series of omni-directional LED bulbs suitable for fully enclosed fixtures"), its temperature management is impressive.

After hours of operation, its lens is merely warm, heatsink is hot but not flinch-inducing in the same manner a fully-warmed incandescent bulb would be.

[1] http://www.amazon.com/dp/B00EW6R0EC (available elsewhere as well)

Should I buy LED or CFL light bulbs?

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