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Christmas Light Energy Usage 101

It’s that time of year- time to drag out the Christmas decorations. Some of you may go simple and just hang lights on your tree. Others may go big and decorate their homes with lights, Santas, reindeer, candy canes and a huge blow-up snowman in the yard. Tis the season, but how many of you have stopped to think of how much this energy usage will cost? Also, have you considered whether your electrical supply can handle the extra strain? Let’s take a look at these details and see if you will still be saying “Ho, ho, ho” or “Bah humbug!”

OK, time to break down the details. A typical large yard inflatable uses about 150-200 watts. If you run it, on average, about 16 hours a day, your monthly cost will be about $8-$10. Miniature lights are now the standard for decorative lighting. The average miniature (incandescent) light uses 0.4 of a watt per bulb. One string of 100 miniature bulbs would only use 6 kWh (kilowatts) per month (100 x 0.4 W x 150 hrs). Let’s say you have about 10 sets of these lights in use, lighting them about five hours a day. The cost of lighting them is about $0.10 per kWh, so this would cost you about $6.00 a month. If you never turn them off, you would be spending about $29 a month. If you use 10 sets LED lights instead of the standard miniature lights, ten sets would cost you about $0.60 a month. Even if you left the LED lights on 24 hours a day, you will spend less than $3.00 a month. That is a big savings.

We can hear you saying, “But LED lights cost so much more than regular lights.” True, LED lights usually will cost you about three times the amount the regular lights will. If you look at the lifetime cost, LEDs have regular lights beat, hands down. As we said, LEDs will use 80-90% less energy and save you on your bill, but they also last longer. Regular miniature lights tend to last about 3,000 hours that is if you can keep them untangled. Led lights last up to 100,000 hours, are more durable and they are cooler, putting you at less risk to start a fire.

Now let’s talk power. Bear with us as we lay some numbers on you. Ready? Here goes… To find the number of watts your outlet can handle, using amps and volts to calculate, use the following formula: amps x volts = watts.

Most household circuits (think electrical plugs) tend to be 15 or 20 amps and have 120 volts, so we will use 15 amps and 120 volts for our calculations. (15 x 120 = 1,800) Therefore, if your circuit is 15 amps it will support 1,800 watts. But remember, you can only safely use about 80% of that circuit. So, 80% of a 15 amp circuit is about 1,440 watts.

Deep breath. Stay with me, we are not done.

Ok, that electrical outlet that you are about to use, does it have another one next to it? Probably and those outlets are on the same circuit. This means they have to share the wattage and so each plug can only use about 700 watts. What does this mean in Christmas light terms? Say you use regular incandescent mini lights and need 10 strings, estimated at about 1,000 total light bulbs. You would be using about 408 watts total, but there is a catch. You can only plug/connect five sets of incandescent bulbs together at a time. If you plug/connect more than five strings of lights together your light strings will blow and not work. Therefore you will need two outlets to safely use all 10 strings of lights. Compare this to LED lights where you can plug/connect together up to 43 strings of 100 bulbs in one outlet and are only using about 69 watts total.

Whew, you made it through all of those numbers and equations. Excellent job! Here are a few simple things you will need to know when choosing and hanging your lights.

Total Watts of a String of Lights:

Watts per Bulb x Number of Bulbs = total Watts

Total Watts for a Circuit

Amps x Volts = Watts

Two outlets on one faceplate = one circuit

More math, we know, but it will come in handy. Let’s not pull a Clark Griswald and put the entire city block out of power.

Lastly, don’t forget to use an appliance timer. With an appliance timer you can choose how many hours and what hours you want to run your lights, saving you money by not having the lights running when you don’t want or need them to. To select the correct timer for your household, check for the amp capacity. An appliance timer will not add amps to a circuit, it just helps support the lights you have plugged into it, so if you have a 15 amp circuit, you wouldn’t want to buy anything more than a 15 amp timer.

Want something even cooler to control your holiday decorations as well as your household lights, fans, temperature and more? Have Godby come to your home to install an energy management coordinator. You will be the envy of your buddies when you can turn on your Christmas Lights or change the temperature at home while you are at their house watching the game.

Don’t let Christmas light safety get you down. If you are not sure if you’re equipped with enough power to win the neighborhood Christmas Light Decoration Contest (and you probably are not), call Godby. We can have a trained electrician come to your home and make sure you can string your lights, have your inflatables, run your moving Santa and play your holiday tunes, keeping the power on and doing it safely. It’s Gotta be Godby, don’t you remember? Call us for all of your holiday electrical needs throughout December.




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