Are LED Christmas lights worth it economically?

LED lights have been making headways for a few years now. Like their A19 counterparts, LED Christmas lights use about 80+% less electricity than their incandescent equivalents. So the question is, how much cheaper are they, and how long does it take to pay them off?

That's a hard question exactly given the fact that the price of them vary wildly. Even an incandescent set of 100 miniature lights can run anywhere for $2-6. LED Christmas lights vary equally wildly, from anywhere from $5-20 for an equivalent 100 miniature lights.

But the cost to operate them doesn't vary that much. That's because the efficiency of them is pretty much the same over a broad set of lights. So I'll focus on the savings, and then you can draw your own conclusions about whether or not they are worth it for you.

Miniature LED lights

A typical incandescent set of miniature lights typically uses about 41 watts of electricity. An equivalent LED set is about 7 watt. That's a savings of about 34 watts per 100 lights. That savings per 1,000 hours of operation (assuming a national average of about $0.12 a kilowatt hour) is about $4.08. So even if the LED lights cost more than $4.08 more for a 100 light set, it'll pay for itself in 1,000 hours of operation, and then save you about 83% to operate every hour after that.

But for most people, it'll take awhile to reach that period. Assuming 30 days of operation at 8 hours a day is only about 240 hours of operation. So it probably won't pay for itself in the first season, but it should within a couple seasons after that. Of course, the more you use them, the quicker it'll pay for itself.

C7 and C9 LED lights

These lights pay for themselves a lot quicker. C7 and C9 incandescent lights use a lot of electricity. You can tell they do because if you've ever touched one when it's been running awhile, it can actually burn you to the touch. I remember at my grandmother's once when I turned it on while it still in the box, the close proximity to each other made the bulbs explode.

Typically, a C7 or C9 bulb uses about 4-7 watts per bulb, or 400-700 watts per set of 100. An LED equivalent is about 45-120 watts per set of 100. That's a savings of about $42-69 per 1,000 hours of operation. That means a set of 100 that cost $20 more for LEDs would pay for itself within about two seasons, and then cost of operation would be $10-16 less per seasons per set of 100 bulbs. That savings add up pretty quickly!

Of course, LED lights have advantages and draw backs. They will last longer, so they're a lot less likely to burn out within a couple seasons. Some people don't like the color, but even then they're getting a lot closer to the color of traditional incandescents.

But purely from an economic perspective, it is still something to consider. With the expenses of the season adding up, purchasing LED lights now can make the financial pain of the holidays a bit less painful later on.

100 watt replacement bulbs finally become affordable

Up until recently, if you wanted an LED bulb A21-style bulb over the 100 watt equivalent, you were probably going to have to shell out a huge amount of cash. The most affordable was the Phillips at about $24.97.

Finally, CREE came out with their 1600 lumen model for less than $20 at 18 watts. FEIT also just introduced their 1600 watt model for $16.99 at Costco, and it only uses 15.5 watts. It's also notable that the FEIT is the first A-style bulb commercially available to hit the 100 lumen per watt efficacy. Compared to a 100 watt incandescent bulb, it should pay for itself in about 12-18 months assuming about 3 hours of use a day.


The FEIT 100 watt replacement on the left, and the CREE 100 watt replacement on the right.

These prices put it well within affordability range. They both have very CREE-quality 2700K light, and are very bright, definitely 1600 lumens. The FEIT seems to be somewhat more omnidirectional. The 1600 lumen CREE version has a similar construction to the lower wattage models where they use a "tower" of LEDs the spread out, but not so much upwards.

These do have a couple drawbacks. The largest drawback is that unlike the lower wattage CREE bulbs, they are not rated for use in enclosures. This is a really important point. I've been using them fine in open-style lamps, but the higher wattage comes at a price of creating a lot more heat. It only goes with the territory. For that reason, the heat sinks (and thus the bulbs) are much larger on these bulbs than they are on the lower wattage bulbs. As you can imagine, the FEIT bulb doesn't get quite as hot at the CREE version since it's more efficient, but the FEIT also is larger, about half an inch taller than the CREE, so take that into account before using in some fixtures. (FEIT does claim on the packaging they can be used in enclosures, but I'm wary of this claim just simply because of the amount of heat they use. The FEIT is more efficient and has a larger heat sink, so this still may be the case.)

In addition, CREE now also makes a 3-way 100 watt replacement bulb, a 30/70/100 watt equivalent, $21.97 at Home Depot. It's very similar to the 100 watt nonswitchable version in both size and light quality. It's actually more similar in light quantity to a 50/100/150 bulb, and much brighter than even 50/100/150 replacement watt CFL versions we tested. The reasoning is simple: a 50/100/150 3-way incandescent bulb uses as much electricity as a 150 watt bulb, but doesn't produce nearly as much light. The reason it because it uses two filaments, one 50 watt and one 100 watt, which isn't as efficient as using one 150-watt filament. LEDs just simply turn on more or fewer LEDs depending on the circuit, making it far more efficient.

IKEA did also introduce a 75 watt version of their LEDARE LED A19 bulbs. They are 1000 lumens and cost $10.99. 1000 lumens isn't quite a 75 watt equivalent (typically 1150-1200 lumens), but it's more than the 800 lumen 60 watts, and their excellent light and cost point are worth mentioning. We haven't yet had a chance to review it though.

Should I wait until better bulbs come out?

Technology changes pretty fast. We're seeing this happen in LED lighting, and a lot right now. Technology is not only improving, but it's getting cheaper too. So it's a fair question to ask, should I wait to buy efficient lighting until the price comes down?

In general, not really. Yes it's true the lighting is getting better and cheaper, but unless the light is really expensive now and expected to come down a lot, and you don't use it a whole lot (so you won't gain from savings), from a completely economic standpoint, it doesn't make a whole lot of sense to hold off.

Let's run a couple calculations to show what I mean. Take your standard 60-watt A19 incandescent bulb, the most common one on the market. At an average use of 3 hours a day, this bulb will cost you about $8.50 a year to operate. A 10-watt LED bulb will cost about $1.40 over the same period. That's a savings of $7.10 in the first year alone.

So unless you're expecting the cost of the bulb to go down $7.10 in a year, it makes sense to start saving now. That might have been the case when the technology first came out, but it isn't much the case today.

The other issue is that technology improving quickly. 60 watt replacement bulbs were about 10-13 watts when they first were introduced. Now they're as low a 8.5 watts. Each watt improvement in efficiency will reduce the cost of the bulb about $3.25 over the expected 25,000 hour life of the bulb, but that is only about $0.14 a year. Considering that holding off replacing bulbs means that you won't be getting that savings back, and it doesn't make a lot of sense to wait long either.

One of the things I'd advise people to do is to try different bulbs out. As bulbs become more efficient, use the newer, more efficient bulbs in a place you use them most frequently to gain the savings quickest. Move older bulbs to more marginal places like closets or utility rooms where they're not used as frequently or light quality isn't as important. (I moved an older LED light to an entryway where I don't use it a whole lot, but I love the fact that it's instantly bright when I walk in the door.) There's almost always somewhere you can put some bulb, and if you really don't like them, hopefully you can pretty easily return them. I've had very little problem returning bulbs to Home Depot, Lowes or Costco if there was a failure or I just didn't like them.

So in general, don't wait. If a better bulb comes out later, try it out if you can move the existing bulb somewhere else. Or, perhaps give the old bulb to a friend who hasn't tried them out yet. Maybe they'll switch too. Either way, everyone starts savings money!

Review of A19 bulbs

I had replaced several standard light bulbs in my house with LEDs. Cost wise, LEDs don't have a huge benefit over CFLs. They often do cost less over the lifetime of the bulb, but we're talking a few bucks. For example, I estimate a CREE 9.5 watt LED light would cost about $31.11 in electricity over its lifetime, versus $42.58 for a 13 watt CFL. That's a $11.46 savings, but considering the bulbs cost about $8-9 more than the CFLs, it would take you a long time to recoup that cost. Their costs are continuing to come down dramatically though and that may make them more attractive in more cases.

They do have several benefits CFLs don't. Of course, they don't have any mercury, so they're safer that way. Many are dimmable, so if dimming is important to you, you can actually save a lot more in electricity than CFLs if you actually dim them. They are far, far, far more durable if you need to switch them on and off frequently. We've had CFL bulbs that were rated for 10,000 hours only to die after about a year of use (roughly 1,000 hours or so) simply because they were frequently turned on and off. CFLs just aren't designed for that. LEDs on the other hand are designed to be switched on and off very frequently, thousands of times a second. Of course you're not going to do that, but still, if you're frequently turning on and off the entrance hallway, you won't have to replace that expensive CFL so often if you use an LED bulb.

And if you either have to change a bulb frequently or it's exceeding difficult to replace (in a high ceiling, for example), their 25,000 hour life can make them an attractive. That's 22.8 years at an average of 3 hours a day, but if you have them on all night, that's 5.7 years at 12 hours a day. Note that is the mean time they'll fail. As LEDs will fade in luminosity over time, "failure" is considered to be when they'll reach 70% of their original brightness. They will continue to work, but dimmer than their original spec.

There's quite a number of 40 and 60 watt replacement LED bulbs. There are some 75 watt and one or two 100 watt LED replacement bulbs too, but they are even more on the expensive side. But like the 60 watt versions, those are coming down in price as well. In addition, LEDs are instantly (or at least almost instantly) on and instantly at full brightness. Many CFLs have vastly improved in this respect, but it still can be annoying. Some LEDs do have a short pause before turning on, anywhere from a small fraction to a full second. Most of the time it doesn't make a huge difference. Once they're on, they're fully bright.

I only reviewed "soft" light LED bulbs, either 2700K ("soft" white) or 3000K ("warm" white). These colors are the closest to your traditional incandescent bulb. Note that a lot of manufacturers make "cool" or "daylight" bulbs that are 4000-6000K. Those bulbs are the most efficient as they come close to a more "pure" white, but a lot of people don't like the color, outside of a bright work station.

Here's a few of my favorite bulbs, and a few that I either didn't like or wouldn't buy again.



CREE 60W Equivalent Soft White (2700K) A19 Dimmable LED Light Bulb

Joe says: Run and get these!

This is by far my favorite. It's pretty much a drop-in replacement for most light bulbs. It has a round shape that a lamp shade can easily rest on. It has no hum, and dims down quite well (probably about 20-25%). We noticed no hum when dimmed, even using a non-LED (but fairly modern) dimmer. At 9.5 watts for 800 lumens, it's one of the most efficient LED bulbs out there. I've had really good results with the down light. (Many LEDs have a large base that cast a shadow underneath it.) They make 40, 75 and 100 watt versions as well. Home Depot just dropped their price on the 60-watt replacement version to $9.97, $15.97 for the 75-watt replacement version. They also just introduced a 100-watt version for $19.97, but it's not yet widely available. It's hard to find a bulb that cheap that works this well.

The only thing I didn't like on it was that you can actually see the LEDs in it. The bulb is frosted, but not terribly so. Frosted glass does absorb some of the light, so I'm sure this was to make the bulb more efficient at the tradeoff of an aesthetic. It's no big deal if you have it under a lamp shade or in a frosted glass. Also, there is a very noticeable dark spot on the top of the bulb. Not a big deal, but slightly annoying.

It's rated at 2700K for color, but it's slightly "cool"er than that. CREE does make a softer "TW" (true white) version, but at 13.5 watts, it's far less efficient, but not that much softer white. I wouldn't recommend that again. For a softer version, check out the Feit one I review below.



Ikea's LEDARE LED bulb E26, globe opal

Joe says: Softest light, least expensive, but not so bright.

This is actually a bulb I didn't want to like at first. For one thing, it's not the most efficient. It's 10 watts for only 600 lumens, about 25% dimmer than your standard 60 watt, even though it's advertised as such. When dimmed, I did notice a slightest hum, but you practically have to have your ear next to it to hear it. It only dims down to about 40%.

But I came to love the light. It's by far the softest light of any of them I've tested. The brightness isn't an issue of where I used it. I use in in my nightstand, and I put a dimmer on it. And it's only $7.49, so it's really inexpensive. They also make a 400 lumen version (roughly a 40 watt equivalent) that's not dimmable for only $4.49 and uses only 6.3 watts. It has the same fantastic light.



Philips SlimStyle 60W Equivalent Soft White (2700K) A19 Dimmable LED Light Bulb

Joe says: Hold off on these, for the most part.

I really wanted to like this one. Philips has made some really awesome quality LED bulbs, although you pay more for such quality. I got the impression this one was an attempt to make a more inexpensive bulb and resolve some of the issues with other LED bulbs. For one, you'll note its odd shape. The reasoning was that instead of placing the LEDs in a horizontal circle outward, they would put it in a vertical circle. That would eliminate much of the problems with downward light. Plus, by placing the LEDs far from the electronics (a big source of heat), it would ameliorate the need for a large (and expensive) heat sink. Its shape is also great for more slender units, so the light near the glass isn't exceptionally brighter than towards the outside. And at 10.5 watts, it's one of the more efficient bulbs out there. And at $9.97, pretty inexpensive.

I really liked the light. It was other things I had an issue with. First off, there is a real noticeable hum to it. It's memorable of some CFLs. And of course if your light needs multiple bulbs, that hum increases by a multiple of those bulbs. It's not terribly loud. But it is terribly annoying. I put four of them in a friend's bathroom, and even a few feet away, it's real noticeable when you turn it on and off. A couple attempts at dimming them even made it noisier. (Luckily I didn't need dimming for this application.)

I eagerly await an improvement of this one. When a newer version sans the hum comes out, I will gladly replace these with them and relegate the old ones to a place where individually the buzz won't be such a bother.



Feit Electric 13.5W Dimmable A19 Household LED Light Bulbs

Joe says: Soft light, bright, great dimming, but not so efficient

They were $10.97 at our local Costco, and some places subsidize them down to $8. I love the light on them. They're probably somewhere between the CREE and the IKEA bulbs in the softness scale. They dim fairly well, but we noticed a very quiet hum when they do. (It could just be the dimmer we had them on.) They do dim down to about 20% and have a similar dimming profile to incandescents.

They have a couple drawbacks. For one, there is a rather noticeable shadow cast below it. It doesn't project down very well. Nor does it project up all that well either. Also, this was by far the heaviest standard bulb I reviewed. The package says 9.6 ounces, compared to 4-5 ounces for the others. It's odd shape might not work so well either. And at 13.5 watts, it's one of the least efficient as well. (By comparison, most 60 watt replacement CFL bulbs are 13 watts.) But if light color and dimming is important to you, this might be a good fit.



Feit Electric 8W Dimmable Decorative Globe LED Light Bulb

Joe says: Bright light, cooler, but great for bathrooms

My local Costco sells 3-packs of these for $19.99, or about $6.66 each. At 500 lumens, they're intended to be a 40-watt bulb replacement. In practice, they're slightly brighter than that. They're more of a cooler light, nameplated at 3000K but probably slightly cooler than that. I've found they work very well in bathrooms, where you like a brighter light, but need multiple bulbs. Since they're LED, they work well in fan fixtures. (LEDs tend to work better in the presence of vibration, like with fans or garage door openers.) They are dimmable. They don't cast their light back very well, but some fixtures that's less of an issue. If you need a brighter light but multiple 40 watt bulbs, this one is a good fit for that.

There were a couple other I wanted to check out but didn't review. Philips has a couple different versions. They tended to be more expensive. I've had good experience with the light on them on an older version, but like I said, I've had just as good an experience with others. (The original ones I tried were subsidized by the local power company.)

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UPDATE (7/28/14):' The CREE 100 watt version of their A19 bulb (actually A21, somewhat larger than the A19 versions) is now widely available.

Philips SlimStyle 60W Equivalent are now $8.97 at Home Depot.

The IKEA 400 and 600 lumen bulbs are now both $4.49. A steal!

Costco's FEIT 800 lumen bulbs are now widely available at $8.97.

Lowes introduced three new 60-watt replacement LEDs, one a nondimmable 3000K bulb for $7.98 (reviewed here), another from OSRAM that is only 8.5 watts for $9.98, a full watt more efficient than the CREE model. I haven't reviewed the latter yet.

An LED arms race?

Both Home Depot and Lowes recently dropped their prices on their A-style LED bulbs. Home Depot dropped the price on their Cree 60-watt replacement LED bulbs to $9.97 (from $12.97). Lowes did similar by dropping their Utilitech 60-watt replacement LED bulb to $9.98 as well (from $10.98). Both bulbs are dimmable and have similar efficiency ratings (9.5 and 9.98 watts respectively).

But Lowes did Home Depot one up by introduce two nondimmable bulbs from Utilitech, one a 60-watt replacement for $7.98 and another a 40-watt replacement for $4.98. Realizing that not every application needs dimming capabilities, but people still love the efficiency, instant-on and instant-bright capabilities of LED, Lowes is clearly seeing an opening in the market. Previously, the sub-$10 market for a 60-watt replacement bulb has been pretty hard to find. And at less than $5, the 40-watt even more so. (Ikea does sell a 400 lumen bulb for $4.49, but Ikea is not as geographically available as Lowes or Home Depot.)

This is clearly where the market has been headed. Philips made a name for themselves in the LED market with its award-winning A-style bulbs. But they too have been introducing lower end models to win over general users as well. They introduced both the SlimStyle dimmable model, as well as a semi-directional, nondimmable model, both for just under $10. Both had deep criticism and they tried to trade off features for price. The SlimStyle was a great design in theory, but clearly-cut corners in technology gave it a noticeable CFL-style hum and the cheapness in quality was clearly visible. The semi-directional model made it ill-suited for many applications. And at $10, they didn't compete well with the omni-directional and dimmable Cree model.

In addition, Conserv-Energy at Costco dropped the price of their 60-watt replacement bulb from $10.97 to $8.97. The bulb competes very well in performance with the Cree, but at 13.5 watts, it's not nearly as efficient. Conserv-Energy has also been refreshing their bulb line, so perhaps they are clearing out their inventory in anticipation of a better performing A-style bulb.

And at $5, the 40-watt replacement is clearly a new floor. A similar model at Costco sold in 3-packs for $20, or $6.67 each. Unlike the $5 model, these are dimmable, but clearly the low price point is actually starting to compete with CFLs (which can cost $1-2 each).

It should be interesting to see where this goes. As designs become more simplified, and as chipset become more integrated, and as economies scale up, more and more people should enter the LED market, continuing to drive innovation and drive performance up and prices down. It should be very interesting to see exactly where this goes.

Will LEDs really last 25 years?

This is actually a really good question. Of course, it's easy to be skeptical. 25 years? Considering 25 years ago is when I graduated from high school, it's difficult to imagine them lasting that long. Then again, I still have a CD player I got as a graduation gift. It still works just fine.

It's important to remember that LEDs are fundamentally a different technology than either incandescent, halogen or fluorescent. LEDs are really mini electronics, much like your cell phone or its charger. LEDs (in most cases) must take your high voltage (110 volt) alternating current (AC) and drive low voltage direct current (DC) LEDs. By stimulating the electrons, it creates light and very efficiently.

So an LED bulb must have something called a "driver". This is a set of electronics, much like your cell phone charger, that must do exactly that. The other way it can get around this is by using an array of LEDs in serial. Most LEDs are really small voltage, in the 1-2 volts range. In other words, not only do you have to convert that AC to DC, but you have to get that high voltage down to 1-2 volts. The more the driver must step down the voltage, the more expensive the electronics are. Newer LEDs get around this by putting the LEDs in an array in serial. Think of it this way: If you put two 1.5 volt batteries in serial, you get 3 volts. Much the same, if you put two 1.5 volt LEDs in serial, you can drive it with 3 volts instead of 1.5. Many LED chips put multiple LEDs in serial on a single chip, and multiple chips add up. Many A-style LED bulbs may have 18 chips with 4 LEDs on a chip, and can be driven with voltage similar to 110 volts. This drives the costs down substantially.

So in short, there's two major parts of an LED bulb, the driver and the LED array. If one of those parts fail, the whole bulb will fail.

That said, electronics for the most part are pretty stable. Your cell phone charger is going to work pretty well, particularly if it's from a reputable company. Your LED bulb is much the same.

If one thing is going to kill those electronics though, it's heat. Many LED bulbs are not rated for working in enclosures because they cannot dissipate the heat. Many of the components are rated to last so many thousands of hours at a certain temperature. The higher the temperature, the less time they're rated to last. So check to make sure your bulb is rated to work in an enclosure before you put it in one. (Only bulbs that are rated to work in enclosures can earn the Energy Star label, so that's a good thing to check for.)

Barring the electronics failing, LEDs, like most other lighting technologies, will get dimmer over time, about 1% or less for each 1,000 hours of use.

So that's where the 25,000 hour rating comes from. The electronics are rated to last for 25,000 hours at temperatures the bulb is rated to operate at. The LED array will get dimmer, but instead of failing "catastrophically" (i.e., burning out), LEDs are rated to be past their lifetime when they reach only 70% of their initial brightness. They will still work, but they won't be as bright.

The process of replacing bulbs that are too dim for most use is called "re-lamping". It's common in replacing fluorescent bulbs. Many LED street lights are expected to last for 7-15 years. They are expected to reach their 70% limit in 7-10 years, but can continue to be used for many years after that. For your use, if a bulb gets noticeably dimmer (let's face it, 10-15 years from now), you may wish to replace it, but use the old bulb in a more marginal place, such as a closet where you want instant on but don't need the light to be as consistent.

LEDs also are subject to very fast changing technology. CFLs in particular are a very stable technology. They're about as cheap and efficient as they're going to be. CFL technology such as dimming has been largely replaced by LEDs, as they're similar in price but performance in LEDs in much better and LEDs last longer. The two largest areas of improvement are price and efficiency. Early 60 watt replacement bulbs were $30-40. They now can be had for as low as $8, even without subsidies from power companies. Except them to drop even lower. In efficiency, the early LED bulbs were about 12-13 watts. Now they're as low as 9.5 and dropping. For that reason, I'm telling people not to replace all their bulbs (particularly their CFLs) with LEDs right away. I wait until CFLs burn out, then replace the LEDs I use most with the newer, most efficient bulbs, and then use the older LED bulbs to replace the CFLs that burn out. I have one bulb in my living room that is used more than any other light that has gone from 30 watts, to 26, to 23, to 18. It doesn't sound like a lot, but at 5 hours a day, that difference does save me about $3/year.

So like most electronics, LED lights will probably either last a couple months or a decade or so. Also like most electronics, keep your receipt for the warranty period (3-5 years for most LED lights, I keep my receipts in the same place I keep my extra light bulbs). If it fails before then, get a replacement. If not, you're probably going to enjoy it for a decade or two to come.

Update on LEDs

I helped "green" the houses of my sister and a couple friends. It's been a few years since I greened my own place, and there's been a huge improvement in a lot of lighting technologies. LEDs have become very reasonably priced, especially considering how efficient they are and how long they last. In addition, they work much better in some applications than CFLs ever could.

First off, two things to look closely at are color and lumens. LEDs are typically a very pure white. Like purified water (which is tasteless without the minerals spring water has), we're not used to consuming it in its purest form. Most people prefer a softer light. Color is measured in Kelvin or K. Higher numbers (4000-6000K) are closer to sunlight and typically aren't used unless you need a pure white light. These are great for photography or displays when you really need it to "pop". But most households use a 2700K (the "softest" light, most typically used for gentle lighting like bedrooms and living rooms) or 3000K (a "warm" white, slightly brighter used in kitchens and bathrooms). LEDs try to get close to a soft light but since LEDs run white, they may be a bit brighter than you're used to. The difference between 2700K and 3000K may be more subtle than their incandescent versions. (Note that in LEDs, cooler whites tend to be 5-20% more efficient per lumen.)

The other thing to look closely at is lumens. Lumens is the measurement of a bulb's brightness. Many bulbs (both CFL and LED) use "watt equivalents" to give the user an idea of what the rough equivalent incandescent bulb would be. The issue is that this number is subjective. Even amongst incandescent lights, two bulbs with the same wattage can have a different lumens. Some 40 watt bulbs can be as low as 300 lumens or as high as 500. Because the brighter a bulb is, the more LEDs have to go into it, that means it costs more to manufacture. So some manufacturers will try and pass a lower brightness bulb as a higher wattage equivalent. Look at the lumens and you can compare apples and apples.

LED have some significant advantages over CFLs. For one, they are more likely to be dimmable, or at least not be that much more expensive for the dimmable version. Some may have issues with older dimmers, but modern dimmers may work (those manufactured in the last 10 years) better, or best yet, buy a dimmer specifically made for LEDs. (They'll work better with dimmable CFLs as well. We had issues with dimmable CFLs until we put it on a dimmer built for such.)

Secondly, LEDs are instant on and instantly bright. There is no waiting time for it to get bright. There may be the slightest pause when first turning on, but it's typically less than a second.

Unlike CFLs, they also work in very cold environments. That can make them a good power-efficient substitute for an outdoor light in extremely cold environments. (Most CFLs will start down to about 0 degrees and may take longer to get bright but will work). They don't, however, work in extremely hot environments. Many are not rated for unventilated enclosures. Check the label to see if it's rated for enclosures first before using in such.

I've noticed that the light from one CFL to another isn't always consistent, even when new, so when using them side by side, slight differences may be noticeable. LEDs work better if you need absolute consistency (within a brand and model, of course).

They are the most efficient technology as well. They're typically 10-25% more efficient than CFLs, and up to 83% more efficient than incandescents. They also last the longest, anywhere from 25,000-50,000 hours. That's 22-45 years assuming 3 hours a day, but in applications where they are on 8-12 hours a day (such as offices), that's 6-15 years. Cities are now using them for street lighting because high-pressure sodium lights have to be replaced every 18 months, whereas LEDs are only every 7-15 years, vastly reducing maintenance time as well as saving money in energy costs.

They are also mercury free. Modern CFLs have an absolute minute amount of them (typically 2-4mg or less), but still some people are concerned about them, should they be disposed of improperly.

The other area that is LEDs individually tend to be quite directional. They can be diffused with frosted glass and such, but this can actually be an advantage. For that reason, LEDs tend to work well for flood and spot lighting. For another reason, flood and spot lights tend to be expensive on their own. A spot incandescent or halogen light bulb alone can cost $4-9, and it'll only last about 1,000-2,000 hours, meaning you'll have to replace it in a year with normal use. Between the bulb costs and the electricity savings, LED flood lights can pay for themselves within about a year. I've also noticed that when replacing directional bulbs (like flood lights), you don't necessarily need as many lumens to achieve the same lighting, because the directionality of LEDs mean fewer lumens more concentrated equal the same lighting effect. Buy one to check if it'll work in your application before replacing all of them.

LEDs also scale down much better than incandescents. Small lights such as candelabra lights that are in the 10-40 watt range get way much lower lumens per watt. A 25 watt candelabra may only give off 195 lumens. That can be done in a LED with only 3-4 watts.

Finally, LEDs tend to work well in the presence of vibration. Both incandescent (particularly those not rated for "rough duty") and CFLs work poorly in areas with fans (like an exhaust fan/light in a bathroom) or vibrations like garage doors.

That's not to say they don't have downsides. The cost can be quite high. Some energy companies subsidize them to encourage people to switch, but without subsidies, they can retail for $10-20 and up. The good news is hopefully you'll never need to replace them. They also don't work in all dimmers, particularly older ones, like those manufactured over 10 years ago.

Also, they tend to be sensitive to high heat. Some people have had issues with using flood lights in insulated canisters or in enclosures. Check if they're enclosure safe before using in such an application.

In most cases, if you can use a CFL, use a CFL. Particularly in more marginal applications (rooms that are not on often, like closets), your break-even point is going to be in the years, not months. Some people like the lights of an LED better, but there's clearly an additional cost to them. With some bulbs like A19s, the cost may not be that much more expensive to warrant the advantages (instant on, dimmable, better quality light), and obviously the more you use the lights, the quicker the payback will be. But if the benefits of an LED get you to use them instead of an incandescent, it's definitely worth checking out.