Strands of lights are ubiquitous this time of year - tangled in leafless trees, framing windows, sparkling their way to Santa's sled. They are a beaming reminder of both the warm feelings of the holiday season and the environmental costs of this time of hyper-consumption. In 2003, a paper published by the Department of Energy estimated that holiday lights accounted for 2.22 terawatt-hours of energy use per year in the United States, which roughly equals the energy consumed by 200,000 homes annually. With numbers like that, coal may be the best thing to stuff in your neighbor's twinkling stocking. He may need it.
Fortunately, Christmas lights have gradually switched over to LED in recent years. They are up to 90 percent more efficient than old-fashioned incandescent bulbs. So, should you trash your old holiday blinkers for their LED counterpart?
From an environmental perspective, it's rarely advisable to discard something that works and replace it with an energy-efficient version, since the energy required to produce your new bauble is often greater than the savings it offers once you use it. It wouldn't make sense, for example, to trash a perfectly good sedan to buy a new Toyota Prius: Producing a car takes a lot of energy, and hybrids are only about twice as energy-efficient as conventional engines.
Holiday lights, however, are an exception to the rule. A new strand of LEDs will last four or five decades, possibly the rest of your life, depending on how long you leave them on (and how long you live). They're also less likely to start a fire, which is important when you're wrapping them around a bundle of kindling like a Christmas tree. If you're still harboring an old strand of incandescent lights, the Earth begs you to ditch it and go for the LEDs. (If it's one of those multicolored, flashing strands, your neighbors would probably second the motion.)