‘Tis the season to light up your house with a bold, beautiful, blinking display of holiday cheer! But, should you use the cheaper but less efficient incandescent strands, or a pricier but more efficient LED option? To explore this issue of upfront and operating costs, we will turn to a beloved holiday hero: Clark Griswold.
The Griswold Home: A Case Study
In the 1989 classic National Lampoon’s Christmas Vacation, protagonist Clark Griswold’s Christmas luminary is composed of “250 strands of lights, 100 individual bulbs per strand, for a grand total of 25,000 imported Italian twinkle lights.” Let’s suppose the cost. Those strands are made of the C9 type of incandescent bulbs (these are the bulky ones you often saw in the 80s). Let’s imagine Clark sprung for 250 strands of premium incandescent lights at roughly $20 a strand. Clark would spend $5,000 upfront. On average, one strand of these would have a total lifespan of 3,000 hours. Each strand uses .50 kWh (kilowatt hours). At 6 hours a day (6:00p to 12:00a) for 30 days of holiday lighting, the Griswolds would use 90 kWh per strand, for a grand total of 22,500 kwH. If stored properly, Clark could get up to 15 years of usage out of these lights. In Fort Wayne, our current electric rate is roughly $0.15 per kWh. This means, for just his Christmas lights, Clark would owe approximately $3,375 for one month of Christmas light usage, not including the power used in the rest of his home.
Now, let’s suppose Clark upgrades his holiday lighting decorations from incandescent to LED strands. On average, a strand of 100 LED lights is $30. For 250 strands for a total of 25,000 lights, Clark would spend $7,500 upfront, $2,500 more than the incandescent upfront cost. On average, one strand of LED lights would have a total lifespan of 100,000 hours. Each strand uses 10 watts. At 6 hours a day for 30 days, the Griswolds would use 1.8 kWh per strand, for a grand total of 432 kWh. Compared to incandescent strands, this is an energy savings of approximately 98%! Using Fort Wayne’s current rate for electricity of roughly $0.15 per kWh again, Clark would spend $64.80 for one month of Christmas light usage, not including the power used in the rest of his home. Clark would offset his higher upfront cost in 22.7 6-hour days of operation! Not to mention, LED bulbs have a lifetime that is tenfold that of incandescent bulbs. Clark could go the rest of his life without replacing a single strand.
You serious, Clark?
To safely light his 250 strands of incandescent lights, Clark would need (83) 20A circuit breakers and a 600A service to his house! Clark’s method of using many extension cords is not recommended! If he changed to 250 strands of LED lights, he would only need as few as (2) 20A breakers depending on manufacturer specification, which the average home could accommodate.
Merry Christmas to all, and to all a good night!
One can clearly see the benefits that LED has over Incandescent, especially in Clark’s case. In residential applications, LED lighting has continued to drop in price, and the cost to operate LED is a fraction compared to incandescent. Lifespan of LED far surpasses incandescent technology, and in commercial applications, LED has a level of customization in color temperature, distribution, control capabilities, and application that incandescent technology is unable to meet, not to mention the time saved by not having to find the one burned out bulb that caused the entire strand to fail, causing you to fall off the roof and break the gutter, thereby shooting a long column of ice into your neighbors upstairs bedroom. If you’re looking to decorate your home for the holidays, an investment in LED lights may be more expensive upfront, but the longevity of the lights along with the energy savings and efficiency to light them more than justify the initial expense, at least if you’re a Griswold. And that’s the gift that keeps on giving the whole year!
Christopher Minning EIT
Associate, Graduate Electrical Engineer