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Shedding Light on Holiday Light Displays: An Energy Cost Comparison


Outdoor lighting displays are one of the most colorful and visible aspects of the holiday season. Have you ever wondered how much these vivid displays may affect your bill? There are a number of advantages and disadvantages to each variety of lighting options available today, including the cost.

The traditional ceramic C7 and C9 bulbs have been in use for decades. Both are bright and highly visible, but the energy will have you saying bah humbug. C7 bulbs are two inches tall and use five watts per bulb. C9 bulbs are three inches tall and are rated at seven watts. These lights are typically sold in strings of 25 bulbs. Operating an average of 150 hours each month (five hours per day), a string of C7 lights would use about 19 kilowatt-hours (kWh) per month, while a string of C9 lights would use 26 kWh. At a rate 10 cents per kWh, a display that uses 10 strings of C7 lights would cost an estimated $19 dollars per month, while a similar display using C9 bulbs may cost $26 per month! Ouch!

Miniature lights may be the most popular lights used today for decorative, outdoor holiday displays. The average miniature light uses 0.4 watts per bulb. One string of 100 miniature bulbs only uses 6 kWh per month. Ten sets of these lights operating at $0.10 per kWh would cost $6 per month.

The newer, light emitting diode (LED) holiday lights use only 0.04 watts per bulb, or 1/10 the amount of miniature bulbs. Due to their solid-state construction, these bulbs are safer and more durable than traditional lights and miniature lights. Ten sets of 100 LED bulbs would cost only 60 cents per month to operate. Though less expensive to operate, LED lights are more expensive to purchase -- up to three times as much as miniature lights. However, at a lower operating cost, LED bulbs more than pay for themselves over a few years. LEDs also have a longer lifespan than incandescent lights.

Comparing the Cost of Holiday Lights
Type Wattage Monthly Operating Cost *
Traditional 5-7 Watts $19-$26
Miniature 0.4 Watts $6
LEDs 0.04 Watts 60 cents
* For a lighting display using 10 strings of bulbs