
Should I buy LED or CFL light bulbs?  - MikeCapone
http://www.mnn.com/earth-matters/energy/stories/should-i-buy-led-or-cfl-light-bulbs
======
munger
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.

~~~
hcarvalhoalves
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.

~~~
tanzam75
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...](http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/lifetime_white_leds.pdf)

> _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._

~~~
hcarvalhoalves
Even the new generation LED lamps are like that (Cree X and such)? I read
something the other day that suggested these LEDs were immune to losing
efficiency over time (the efficiency would be dictated only by heat).

~~~
tanzam75
Yes, LEDs will last longer without heat issues. But unless you're running the
LED in a refrigerator, that's not a particularly informative statement.

As stated in the DOE that I linked to: "The primary cause of LED lumen
depreciation is heat generated at the LED junction." Because it's the primary
cause, you can't just ignore it and say that LEDs barely degrade in the
absence of heat. You have to consider the heat when calculating LED lifetime.

The stated lifetime on the LED packaging makes a number of assumptions, one of
which is that the LED is run at room temperature.

------
greenyoda
_" 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.)

~~~
ericd
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.

~~~
greenyoda
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?

~~~
ericd
Heat pumps actually move existing heat indoors, from outside, using
electricity to do the mechanical work, so it's much more efficient than just
using electricity to create heat directly.

~~~
mistercow
More specifically, heat pumps often have a COP of around 2, even in very cold
weather (-20℃). That means that for every two joules that a light bulb turns
into heat, you will save only one joule (and less in most conditions) on your
overall energy consumption.

In very, very cold areas, the COP of the heat pump will reduce to 1, and in
those cases the incandescent bulb isn't wasting any energy.

~~~
ericd
Thanks for putting specific numbers to it. It's really surprisingly efficient,
especially at warmer temps (0℃) which are more common in most of the US.

~~~
mistercow
That number is also assuming that the pump pulls from the air rather than the
ground. Ground based pumps are apparently more efficient (well, energy
effective; efficient is not quite the right word in this case) because the
ground warms up in the sun more than the air.

------
dorfsmay
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.

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

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

~~~
trafficlight
Brand new. I bought 10 new CFLs at Home Depot a few weeks ago and returned
them a half hour later.

------
nickhalfasleep
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](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)

------
Edvik
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.

~~~
snogglethorpe
> _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.]

------
programminggeek
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?

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

------
ars
> 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
They linked the article that mentioned that 200 lumens/watt lamp (
[http://www.treehugger.com/energy-efficiency/philips-shows-
br...](http://www.treehugger.com/energy-efficiency/philips-shows-
breakthrough-200-lumenswatt-warm-white-led-lamp.html) ), 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"_.

------
ruswick
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
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.

------
mmagin
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.

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

------
thomas
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...](http://www.amazon.com/LED-Lighting-Primer-
Future/dp/1449334768)

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

------
MichaelGG
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.

~~~
rhizome
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.

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

~~~
rhizome
It would depend on the opacity of the shade itself.

------
jpollock
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)

~~~
tanzam75
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.

~~~
jpollock
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.
:)

------
droidist2
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.

------
a3n
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...](http://www2.epa.gov/sites/production/files/documents/cflcleanup20120329.pdf)

It's not always about efficiency.

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

~~~
bhauer
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.

------
acurious1ne
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.

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

