海角大神

Saving Pennies or Dollars is a new semi-regular series on The Simple Dollar, inspired by a concerning frugal tactics that might not really save that much money. I鈥檓 going to take some of the scenarios described by the readers there and try to break down the numbers to see if the savings is really worth the time invested.

Stephen writes in: with Christmas coming around, what about LED Christmas lights verses regular (incandescent I assume) lights. This is our first Christmas in our new house, so we鈥檒l probably buy some lights soon.

Today, Christmas lights are generally sold in one of two general types: 鈥渕ini鈥� lights and LED lights. The exact energy use of these different light types varies quite a bit, so I went down to my local Home Depot and looked at a lot of different strands.

My numbers indicated that the average wattage of LED lights is about 0.1 watts per bulb, while the average wattage of 鈥渕ini鈥� lights is about 0.4 watts per bulb. We鈥檒l assume that for calculation purposes.

So, let鈥檚 say you鈥檙e going to hang 500 lights from your home, you鈥檙e going to have these lights on for 30 evenings during the holiday season, you intend to run them for six hours per evening, and you hope to use the strands for five years. I think these are all reasonable assumptions.

With the LED bulbs, you鈥檒l be using about 0.3 kWh per day to run the bulbs, given the six hour assumption above. That adds up to about 9 kWh per holiday season, or 45 kWh over five years. At an average cost of 0.11 per kWh from your electric company (this is a rough nationwide average), the cost of running the LED bulbs over that five year span is $4.95.

With the 鈥渕ini鈥� bulbs, you鈥檒l be using about 1.2 kWh per day to run the bulbs, given the six hour assumption above. That adds up to about 36 kWh per holiday season, or 180 kWh over five years. At an average cost of 0.11 per kWh, the cost of running the 鈥渕ini鈥� bulbs over that five year span is $19.80.

In other words, you鈥檇 save about $14.85 over the five year lifetime of those 500 bulbs by using LEDs instead of 鈥渕ini鈥� bulb strands.

The real question is whether or not you can make up that $14.85 when buying the bulbs. Can you make up $14.85 when buying 500 mini bulbs versus buying 500 LED bulbs?

After examining the prices at a lot of different places, I would say you could save that much or perhaps even a bit more鈥� but only if you鈥檙e buying right now at full prices. In November and early December, Christmas lights tend to sell at a very high price.

However, there are tremendous sales on Christmas lights right after Christmas. It鈥檚 not uncommon to see 100 bulb strands for $1 during such sales. My wife and I have several strands of LED bulbs in our garage that we bought at such a post-Christmas sale.

So, what should you do? If you鈥檙e absolutely convinced that you must buy bulbs for this year, the lowest total cost will probably come from buying 鈥渕ini鈥� bulbs provided you can find them for $3 per 100 bulb strand less than the LED bulbs. If you can鈥檛, the LED bulbs are going to be the better deal.

If you can possibly wait, though, do so. Buy a big pile of LED bulbs shortly after Christmas during the big bulb sales because you should be able to find strands of those at a very inexpensive price (and probably very close to the price of the 鈥渕ini鈥� bulbs).