Energy Smart Colorite 100-Light LED Warm White Mini Light Set Energy Smart 100-Light LED Multi-Color String Light Set 100-Light Clear Mini Light Set 100-Light LED Warm White M5 Light Set 100-Light LED Warm White Mini Light Set Energy Smart Colorite 50-Light LED Warm White Mini Light Set C9 25-Light Clear Color Incandescent Light String 50-Light 20 ft. White Lights Solar String Light 50-Light LED C3 Crystal Purple Light Set 100-Light LED Multi-Color Mini Light Set 10 ft. 25-Light Orange Battery Operated String Lights (Set of 2) 150-Light LED C6 Warm White String Light Set String-A-Long 100-Light White Wire Clear String Light Set 100-Light Multi-Color Mini Light Set 9 ft. 36-Light Battery Operated LED White Ultra Thin Wire (Bundle of 2) String-A-Long 100-Light Green Wire Clear String Light Set 300-Light Clear Incandescent Light Set 60-Light Outdoor Battery Operated LED Warm White Micro Light String 200-Light M5 LED Cool White Light Set

150-Light Clear String-to-String White Wire Light Set 6 ft. 7-Light Incandescent Multi-Color Traditional Bubble Light SetEvent Furniture Rental Austin Tx Energy Smart 50-Light LED Multi-Color C5 Light SetAre Wall Mounted Faucets More Expensive To Install String-A-Long 100-Light Clear ConstantON Miniature Light SetVintage Wrought Iron Patio Furniture Makers 50-Light LED Warm White Snowflake Light SetHistory of Christmas Lights First Christmas tree with electric lights, 1882 Christmas lights have been one of the most popular Christmas decorations for the past century. In 1882, three years after Edison invented the first sensible light bulb, Edward H. Johnson created the first Christmas lights in his home in New York City.

The tree was hand-wired and lit with 80 red, white, and blue globes. The lights blinked and twinkled while the tree slowly revolved. Christmas lights were first made available for sale in 1890, but they were so expensive that most people could not afford them. They were a symbol of status among the wealthy and many of them rented the lights instead of buying them. In 1903, one set of 24 Christmas lights was sold for $12.00. Considering the average person made about $9 a week, this was far too extravagant for the normal family. In addition to the cost of the lights, the services of a wireman were required and, if the house was not electrically powered, they also needed a generator. Christmas lights did not become practical for the average family until the 1930s. By this time, not only homes were decorated with electric lights. Stores, community Christmas trees, and government buildings were adorned with the twinkling lamps. General Electric began to sponsor community lighting competitions in the 1920s, but it wasn't until the 1950s that it was common to see rows of houses lit on the outside.

Today, the places you find the lights are as numerous as the types of lights available. Varieties of Christmas Lights Mini-light strings: Most popular because of their versatility. LED Christmas lights: Energy-efficient alternative available in a variety of sizes including LED C6, LED C7, LED C9, LED Wide Angle, and LED icicle stringers. Battery-powered mini-lights: Used in even more applications. Rice lights: Tiny points of light for smaller decorations. C7 & C9 bulbs: Most prominent outdoor lights because of their larger size and greater luminescence. Globes and Teardrops: Stylish indoor alternative available in a variety of sizes including G8, G23, G25, G28, and G40. trunk wraps: Easy way to decorate bushes and trees. icicle lights: Mini-light strands that hang vertically. Lighted decorations: Christmas Stars, lantern lights, and starlight spheres are favorites. Commercial decorations: Perfect for stores, malls, and businesses and feature bows, wreaths, festoons, giant candy canes, Christmas topiary, and even life-size figures.

100-Light LED Warm White Icicle Light Set 108-Light LED Multi-Color Ribbon Lights 48 ft. LED Daylight Rope Light 24-Light ColorMotion Icicle Deluxe Light String 16 ft. LED Blue Rope Lights AppLights 24-Light LED C9 Shape String Light Set AppLights 24-Light Multi-Color Icicle String Light Set 24-Light Battery Operated LED Icicle Light (Set of 2) Black-Outdoor LED Spot LightMost people that are putting up Christmas decorations have already finished the task. Of course, if you are a business or a city you probably put up lights before Halloween – I have no idea why. So, of course I want to estimate how much money these lights cost to run over the holiday season. Let’s get to work. To start, I will get an idea of how much power a strand of Christmas lights uses. There is this fairly awesome device, the Watts Up Pro. Basically, you plug different devices into it and it tells you the power that device uses. The other cool thing is that you can plug it into your computer and record changes in power using Vernier’s Logger Pro software.

Here is a fairly standard string of 100 lights with the Watts Up Pro. That’s 44.7 watts for 100 lights or 0.447 Watts per tiny bulb. What about the whole tree? Well, I could just estimate the number of lights on there but I lost track. My wife really likes lots of lights. I feel bad for saying this, but I measured the power – 508 watts. That is way more than I expected. If I assume all of the bulbs are 0.447 watts, this would mean there are over 1,000 lights on that darn tree. What else do we have Christmas lights on? Well, the kids have small trees in their rooms and there is another small tree by the door along with a lighted wreath. This puts our indoor Christmas lights at around 800 watts. Just for a comparison, my coffee pot uses about 650 watts while making coffee and my refrigerator averages to under 100 watts over a day. What about the outside lights? For me, I am at 474 watts. This means that my Christmas spirit consumes around 1,300 watts. I am killing the planet with my spirit.

Now for the estimation part. With any estimation, you have to make some assumptions. You can see that I included variable names for these estimates so that I can write down my calculation as an equation (then the values can easily be changed). OK, first, how much energy was used? Remember that power is the rate of change of energy: Using my estimates for lights, I can write the U.S. energy usage for Christmas as: Then the total cost would simply be this energy times the cost per energy. However, my energy is in Joules, or watt*seconds. I can convert this energy cost into dollars per joule: This puts the cost at: Just make sure that c is in the correct units – also Tavg needs to be in seconds, not hours. Putting in my estimates, I get an electricity cost of $233 million. That’s not too bad. I mean, it’s a lot of money – but this is the USA we are talking about here. I would compare this to the energy saving by switching out of Daylight Saving Time – but I fail to see how to get a good estimate for that.

I hate that one of my favorite Christmas movies is Christmas Vacation because it isn’t really appropriate for the whole family. But it sure is funny. So, what about Clark’s lights on his house? How much would that cost? First, there is an important difference with the Griswold house. Clark Griswold apparently uses the old-style Christmas lights. You know, the ones with the big and hot bulbs. I don’t have a string of these lights to measure. However, I did find a bulb that looks similar in a Christmas night-light. It runs on 6.3 watts. But how many lights does Clark use? That’s a tough one. Let’s start with a bulb area density. If I assume the door in the screenshot above is 2 meters tall, I can get an estimate for how many light bulbs are used per square meter. With some basic counting, I am going to go with 20 bulbs per square meter. The main roof of the house is about 15 meters wide – but there is also a garage that is maybe 4.5 meters wide. I will just estimate the total roof area at about 19 meters by 10 meters.

Let me include another 30 square meters to account for the lights on the front of the house (assuming no lights on the back). This puts the light-covered area at 220 m2. How many light bulbs? This would be (220 m2)*(20 bulbs/m2) = 4,400 bulbs. If each bulb is 6.3 watts, the total power would be 27.7 kilowatts. There are lots of different estimates out there for the household power uses. An estimate (averaged over a day) is probably between 500 and 1,000 watts (but not during Christmas). That might seem like a low estimate, but remember that for probably half the day, there isn’t much going on in the house (electricity-wise). So Clark’s house is clearly beyond the norm. How much would this house cost to power the lights? Well, first, Clark probably paid the 1989 electricity rates. I’m not sure what those rates were, but they had to have been lower than 10 cents per kilowatt hour. If he ran that exact setup with today’s rates for 4 hours, that would cost $11 a day – or 4.6 cents per minute.

It seems like in the movie, he put the lights up fairly close to Christmas so maybe he only had these lights up for a couple of weeks. What if Clark used the smaller lights that are popular now? These aren’t as bright, so he would probably have to double the light density to maybe 40 lights per square meter. Assuming a power per bulb of 0.447 watts this would give a total power of 3.9 kilowatts and a cost of $1.56 per day. I should have also looked at the LED lights, but I didn’t have any of those to test (yet). But what about the current going through this outlet? From the movie, it seems like all of the lights are plugged into just this one outlet (and that was the reason he couldn’t get the thing to work). What kind of current would this have? In terms of current, I can write the power as: Of course, with household circuits, both the current and the voltage are alternating at 60 Hz. If I use the root-mean-square current and voltage (RMS), I get the RMS power (which is what the Watts Up Pro gives).

Oh, what the heck is up with using RMS? Well, if you plot the voltage (or current) as a function of time, it is positive half the time and negative half the time. If you averaged the current over one whole cycle, guess what you get? You get zero amps. So, the trick is to square the current and then find the average. After that, you can take the square root of this squared average. It gives a non-zero value that is a good representation of the average current. In the U.S., the standard outlet RMS voltage is 120 volts. With this, I can solve for the RMS current. If the lights use 27.7 kWatts, this would be a current of 230 Amps. A typical high-current device like a vacuum cleaner is typically less than 10 amps. According to Wikipedia, it looks like the highest-current circuit breaker trips at 125 Amps. So … how did Clark Griswold get his outdoor lights to even work? Maybe he shorted out the circuit breaker – which would be dumber than giving Jelly of the Month as a gift. How hot would the wires get?

So, the extension cord that Clark plugs in looks like a standard cord. First, these things are only rated for like 13 Amps, not over 200 Amps. But it looks like they are about 16-gauge wire inside with a diameter of 1.291 mm. So, let’s say I have 1 cm of this wire. What resistance would it have? Using the resistivity of copper (ρ), I can find the resistance: At room temperature, copper has a resistivity of 1.68 x 10-8 Ω*m. So, my 1 cm section of wire would have a resistance of 0.00128 Ω. Notice that if the wire had no resistance at all, it wouldn’t get hot. Also, as the wire gets hotter, the resistivity goes up too. I’ll just stick with this one value for now. Now, let’s say I run current through this wire for 60 seconds. Now that I have the resistance of this little piece, I can calculate the power it dissipates (by having resistance). Using a current of 230 Amps, this little piece of wire would have dissipated 67.7 Joules of energy. Let’s say just half of this energy goes into an increase in thermal energy of the little segment of wire and the other half of energy gets radiated out (or heats up other things like the wire insulator).