If it seems like the holiday light displays in your neighborhood are getting bigger every year, there’s good reason for it. Prices on LED string lights have come down substantially since they first appeared in stores, and the cost to operate them is a tiny fraction of what it costs to power old-fashioned incandescent bulbs. So, with that huge slash in energy consumption, we’re wondering just how much sweat it would take to make the average home merry all season long.
How Much Electricity Do LED String Lights Use?
We can’t overstate the energy efficiency gains in switching from incandescent bulbs to LEDs. Old-fashioned incandescent mini string lights draw about .41 watts per light, compared to .07 watts per light with LEDs.
The decorating supply website ChristmasDesigners.com illustrates the difference with a hypothetical holiday light display for the average two-story, single family home: 2,450 lights to illuminate trees and front lawn foliage, 200 bulbs for a roofline perimeter and 150 bulbs to outline the sidewalk and driveway. With incandescent bulbs, this display would draw 2,800 watts. But with modern LEDs, the same display would draw only 237 watts — more efficient by a factor of nearly 12.
Let’s see what the difference would be in terms of exercising to keep each of these displays going for just one hour.
How Many Calories Will It Take?
If you’ve been following our posts about powering appliances with human energy, you know that one calorie is the equivalent of 4.1868 watt-seconds, with a watt-second being the amount of energy it would take to sustain one watt of electricity for one second.
With that rate in mind, let’s take a look at how many calories worth of energy it would take to power up each of these displays for one second.
2,800 watts ÷ 4.1868 watt-seconds ≈ 669 calories per second for the incandescent display
237 ÷ 4.1868 watt-seconds ≈ 57 calories per second for the LED display
How Much Hockey Would It Take to Light Up the Lawn?
In the spirit of the winter holiday season, we thought ice hockey would be an appropriate way to expend the physical energy needed to make the season bright. It’s also a high-intensity exercise — according to the Compendium of Physical Activities, ice hockey generates an impressive 8 METs, or metabolic equivalents. We’ll need that measurement to determine how many calories we’ll burn playing hockey.
We’ll also need the weight of the person doing the exercise, so for that, we’ll turn to the Centers for Disease Control and Prevention’s estimates for the average American adult: 88.76 kilograms for men and 76.43 kg for women.
Let’s see how many calories our athletes will burn during an hour of ice hockey:
8 METs x 88.76 kg ≈ 710 calories per hour for men
8 METs x 76.43 kg ≈ 611 calories per hour for women
Now let’s see how much hockey playing it would take to light up each of these displays for an hour. Our incandescent display gobbles up 669 calories per second, which comes out to 2,408,400 calories per hour. And our LED display uses only 237 calories per second, with a result of 205,200 calories per hour.
So to keep that power-hungry incandescent light show going for an hour, our male athlete would have to play hockey for 141 days, eight hours, six minutes and 46 seconds. But to light up the LED display, he would only have to hit the ice for 12 days, one hour and 51 seconds.
For our female athlete, it would take 164 days, five hours, 44 minutes and five seconds of hockey to make the old-fashioned display glow. Compare that to powering the LED display with just 13 days, 23 hours, 50 minutes and 34 seconds of effort on the ice.
So if you’re still using yesteryear’s holiday lights, consider making this the year you upgrade to energy efficient LEDs. Even if it doesn’t save you four months’ worth of getting checked into the boards for an hour of twinkling lights, it could save you a bundle on your electric bills.
Check out how much exercise it would take to power your other appliances!