Five Percent: Conserve Energy

Climate Change Is Important: Energy Conservation is the First Step


December 7, 2008

Should I Really Replace My Holiday Lights with LED?

Category: Household,Little Things,Save Electricity,Tips – Tom Harrison – 3:11 pm

Replace?

Replace?

We’re putting up our Christmas tree today and thought about using LED lights this year — many eco sites recommend that you replace holiday lights with LEDs to save electricity, and this may be good advice … or not.

But before I get too complicated, I think it’s safe to say that if you don’t have working lights now, and are buying new ones for decoration, LED is definitely the best choice.

So go ahead and replace your lights, right? Not so fast. By “replace” do you mean get rid of the working ones you have now and buy ones? It’s a bit trickier in this case, but here are some facts that might help you decide.

LED lights are better for this application in almost every way than the alternatives:

There are several types of holiday available:

  1. C7 incandescent having a small candelabra screw-in base (usually indoor)
  2. C9 incandescent having a small candelabra screw-in base (usually outdoor)
  3. Mini-light strands sometimes having push-in replacement bulbs
  4. LED, available in several forms (including screw-in replacements for C7/C9)

Each type has a special electric strand having sockets for the bulbs, and a plug, and can usually be chained together. As you can see from the chart, the electricity use of each bulb is dramatically different. But so is the light output. To simplify things, I assumed that a single strand of lights would produce about the same amount of light, which I borrowed from this public utility writeup (pdf).

So while a single C9 bulb uses more than 70x that of an LED, strand for strand, the C9 bulbs use about 30x more electricity. Our mini-bulbs use a more modest 7.6x times as much per strand.

But this doesn’t take into account the entire cost of the product over the course of it’s lifetime. This “lifecycle” valuation is more relevant to big things like buildings and cars, but it is worth thinking about in pretty much any context when you’re buying something, especially when the reason is just “because it’s green”.

Here are a few questions that occurred to me in making our decision.

  • By replace, do you mean buy a new LED strand to replace a working strand?
  • Are you going to drive out to get them? How far?
  • If you’re throwing out a non-working strand, could it be repaired?
  • Do you already have enough lights? Could you get by with one fewer strand?
  • How many hours will you have the lights on?
  • Instead of buying 2 strands at $30, why not try just one strand plus 5 GE CFL bulbs for use all year round?

In our case, we should stick with the mini bulbs that we have had for a few years. They work, we have several strands, and according to my Kill-A-Watt they draw 87 Watts when on. We’ll have them on perhaps 5 hours a day for the next 30 days, or about 13kWh more than equivalent LEDs would use. At our rate of $0.22/kWh that’s $2.87 (which is about 3% of our monthly electrical use).

It doesn’t sound like replacing our current lights is the best choice for us … this year. But it’s hard to say since I don’t really know the total “burdened cost” of the product over its lifetime. It might be different if we had the regular C7 bulbs which would be closer to $10 for us. And if we had lights outside, or were replacing, it’s a sure bet. But we don’t.

Wouldn’t it be nice if products came with labels that gave us all of the information we needed to make an informed decision?

8 Comments

  1. Part of the equation for replacement should also include the landfill costs. What is the cost to the environment for throwing out a working and/or marginally working strand?

    Comment by Ann — December 7, 2008 @ 11:11 pm

  2. Not to mention materials used in source material acquisition, manufacturing, packaging, transportation (parts, packaging, and people, to and from the various places over the globe to get these to the store… and home), and a zillion other little things. Some of them are included in the cost we pay at the store. The “fully burdened” cost would include all of the facets like CO2, and potentially many others that simply are not costs borne by anyone (in dollars, at least) … for now.

    Comment by Tom Harrison — December 8, 2008 @ 11:27 pm

  3. We replaced all the outside mini light strings last year, after accumulating 10 years worth of partially working sets. I think we’ll swap into LED lighting when these need replacements, and the LED lighting improves. We use “white” lights outside, and the LEDs on the market today are tinted blue.

    On a related note, have you tried any of the LED-based replacements for mini-flood halogen lamps (MR16 size). I swapped out the tungsten lamps a long time ago, but we have lots of recessed halogen lighting that we basically try not to use so much now.

    Comment by Ho John Lee — December 10, 2008 @ 2:07 am

  4. Hi Ho John —

    I haven’t tried any LEDs beyond a nightlight yet (which does have the cold/blue cast associated with LEDs).

    I have asked several distributors for samples claiming a 3000K color temperature and which are dimmable in two styles I can use: PAR20 (small ceiling lights, currently 50W halogen/incandescent) and R30 (standard ceiling floods, incandescent, 75W). Both are not so great in their CFL variants (despite my initial enthusiasm a couple years ago) — dimmable CFLs tend to have limited range, and lousy color temperature when not on full power.

    The first distributor blew me off. Maybe someone who has a good consumer product will take me up on my offer to write a review. I was willing to pay extra for CFLs when they first started to not suck, but at $55 for a single bulb, I am more inclined to let a confident manufacturer, distributor or reseller to take the chance :-)

    Tom

    Comment by Tom Harrison — December 10, 2008 @ 6:49 pm

  5. I’d be happy with MR15 sized LED lamps with a plausible color temperature and output. Someone else mentioned to me recently that they might have found a source of usable LED-based replacements, I’ll let you know if I hear anything more from them.

    Comment by Ho John Lee — December 11, 2008 @ 1:53 am

  6. I say go with LEDs if you’re buying new ones. A BIT too expensive, but they’ll last a long time, they look great, and they use almost no energy in comparison.

    Check out our Green Gear review of GE’s StayBright 100 LED Strand of Christmas Lights HERE.

    Later!

    Comment by Mr. Green Gear — December 19, 2008 @ 10:13 am

  7. Yep — LEDs are a no-brainer if you’re replacing, and GreenGear is a great site.

    Comment by Tom Harrison — December 19, 2008 @ 4:49 pm

  8. I was so fed up paying the high electric bills, I decided to try out LED lights. I bought the LED lights to replace my old bulbs – CFL and incandescent – and guess what – my electric bills did drop a lot! I also found a great site to buy the LEDs called LEDinsider.com that I would recommend enthusiastically. They had good service (good phone and email support), great FAQs so I knew what I needed, and competitive prices; also, their shipping was fast and the LEDs were as good as advertised. http://www.LEDInsider.com. Very good online shopping site.

    Comment by Clark — January 10, 2009 @ 1:44 am

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