How much does it cost to run Christmas lights? This is tough to answer because the price of electricity varies from place to place. The Internet to the rescue!
In this post from The Science Club, they tested different Christmas light around town with a watt meter. A 7-foot Christmas tree decorated with white mini-lights used 150 watts, about $.02 an hour, while another tree with regular lights used 269 watts, about $.03 per hour. If these people left the tree on 5 hours a night for all of December, that’s $3.10 and $4.65 on their bill, respectively.
What about LED lights? We switched to those last year. While they cost more to buy than regular lights, they are a lower fire risk and look more colorful on the tree. According to this site, a strand 50 regular lights uses 300 watts where a strand of 50 LED lights uses only 4 watts.
But wait a minute. This site is saying that a STRAND of light uses 300 watts, more than a whole tree on the other site? I guess this indicates that the amount of power can vary? Or that no one really knows because there are too many variables?
Your best bet to figuring this out is this Energy Cost Calculator, which lets you calculate exact numbers based on what Christmas lights you have in your house.
We use 5 LED strands and one regular strand, which ends up being about $.02 an hour to run. If we leave the tree on for the next 15 days at 5 hours a night, that will cost us $1.50 extra on the electricity bill.
Pshah. Money well spent.