LED lighting economics


I broke down and tried a couple LED bulbs in my house.  We have track lighting in the kitchen with PAR20 bulbs, usually the 50W halogen type.

The Home Depot recently started carrying some decent LED lighting, manufactured by Lighting Science Group right here in the US.  They have a PAR20 form factor for about $25, which does seem awfully steep for a bulb.  (Lowe’s has a version from Sylvania for about the same price).

(edit: the price is $20 as of Sept 2011 – Eric)

But if you look at the long-term economics of it, it makes a lot of sense, even at $25.

I pay $0.10/kWh for my electricty.  These bulbs are 8W, and they replace my 50W bulbs, for a net savings of 42W.  They’re rated for 50,000 hours (5 year warranty) so (42W x 50,000hrs x $0.10/kWh / 1000W/kW) is a savings of $210 over the life of the bulb, if it really lasts that long.  On top of that, a “long life” $8 halogen bulb lasts 4,000 hours, so I’d need to  replace that halogen bulb 12 times, at $8 a pop for another $96, so this is $71 more than the material cost of the LED bulb.

Anyway, end of the day – even at $25/bulb if they perform as advertised, they’ll save $281 each over the old halogens.  If I replace all 6, at a cost of $150, I’d save over $1600 over the life of the bulbs!

Sounds great right?  But 50,000 hours is a lot.  At 3 hours a day every day, that’s over 40 years.  :)  Still, the break-even comes much sooner than that – assuming rates are steady, 4 years saves about $18, 1 avoided bulb change saves $8, so I’d say break-even in 4 years.

Now, as for the quality; they are a little more focused than the old halogen floods, and they are definitely a whiter color; 3000K is smack between “Warm White” and “Bright White” on the lighting facts label, but it looks pretty white to me, to the point where I’m not sure I like it, unfortunately.  Sylvania claims to have similar bulbs at 2700K which is yellower, but I can’t find those for sale anywhere.

Apparently Home Depot will also be selling a version of the Philips bulb submitted for the L-prize, which is supposed to be a true 60W replacement and a nice warm white… for $40-$50!  The long-term economics will still be a win, but that’s some sticker shock for sure.  Of course, this is how CFLs started out a couple decades ago, too.

10 thoughts on “LED lighting economics

  1. I started with LED lights a few years ago already; mostly imported from China though. While the price is about the same (sometimes higher actually), in my experience they tend to perform quite decently.

    I use them in my bathroom and bedroom, where not much light is needed, but on the whole, they provide the right light for near to no power, they are all rated (and as far as I can tell it is correct) between 1.2W and 2.4W each. The most I have in my bedroom where I put an originally halogen-designed fixture with four bulbs (4x50W), and is running instead 4×1.8W LED.

    Sure they probably have a lower lumen-to-power ratio, but I don’t _want_ more light on my bedroom, thus why CFL were trouble by themselves.

  2. I’ve thought seriously about moving to LED too. The primary thing which holds me back is claims vs reality. The claims about LED are great. There isn’t too much data on the reality side yet, especially as regards longevity and performance over time. I saw many of the same claims for CFLs and IMO they have abysmal performance and nowhere near the stated longevity (unless perhaps they are in a location that is turned on once and then runs for life). I wonder how many individual LEDs in the array can go dark before it becomes noticeable. I’m certainly watching the devices. Maybe you’ll have a report on performance before I need to take the plunge :).

    • Agreed, some of the CFLs were dismal. Others were great. Like anything, a market grew up and people went in for a quick buck.

      I think that other than reliability, the new lighting facts guides should really help consumers know what they’re getting.

      As for how many LEDs in the array could go out… AFAICT these ones I got have a single LED, but I’m not sure; maybe it is an array behind a lens.

  3. I’ve recently moved the lighting in my kitchen to LEDs as it’s by far the area most continuously lit. We have a mixture of bright Blue/White LEDs and some warmer yellowish ones which are fairly close to the original halogen light we did have there.

    However I was disappointed to have my first failure a few days ago after only a couple of months. I haven’t dissected the bulb yet but I’m fairly sure it’s not a LED failure and more to do with the transformer. This is going to be a big problem while we transition from high energy bulbs, having to step down the voltage in each lightbulb presents another failure point and raises the cost per bulb.

    • I just lost a bulb after a year …. :( Home Depot replaced it with no hassle – but that means I didn’t get to dissect it.

      Keeping receipts seems like a very good idea, for long-warranty, expensive bulbs…

  4. I think the only reasons to replace them with LED (when they fail) might be the much longer lifetime and potentially better light quality (color, instant-on, dimmable etc). In my case, I couldn’t find any suitable PAR20 CFLs for this fixture. The lumens/watt for LEDs I’ve seen is about the same, or sometimes less, than the CFLs, so not sure efficiency is a good argument.

  5. There has been controversy about the Philips bulb because they initially sold it with a certification mark that it had not earned. Philips is one of the companies pushing the leading edge of LED lighting available for home use. But it still doesn’t look quite right because of the extra blue light that comes through with the white.

    I’ve seen LED lighting in the lab that blows away anything we can buy in a store right now. Capable of proper white, for example.

    LEDs shouldn’t “go dark.” When they do, something else is wrong–a loose connection, a faulty power converter, or lamp design that does not pull heat away from them well enough and “cooks” them. When properly mounted, the rated life of an LED lamp is how long you can use it before it dims to a certain level.

    I’ve written up an explanation at my website about why each type of lighting looks the way it does, and its strengths and weaknesses–not limited to energy efficiency. I hope I’ve made it understandable for people who are not heavily technical. When the light I’ve seen in the lab becomes commercially available, I’ll post there to let people know.

  6. Pingback: LED lifetime update | Eric's Blog

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