Above: Image © PiccoloNamek, Wikimedia Commons

The Christmas season, particularly in North America, is fraught with blatant consumerism. Let's face it, for many of us, the holidays are simply not the holidays without all the holiday parties, rich food and gifts. Amidst all the hustle and bustle of shopping, spending and gift-wrap, and the constant barrage of friends and family, the drive to conserve and practise green- or eco-friendly living often gets pushed to the wayside.

There is however, and has been for quite some time now, a way to help out the planet and still get into the holiday spirit. Christmas lights, those ubiquitous sparkly strands wrapped around indoor trees and strung up in beautiful outdoor displays are a sure-fire way to ignite feelings of yuletide cheer. But did you know that the type of Christmas lights you use can actually cost or save you money on your energy bill?

Did you know? While they've been available since the 1960s, LED lights are only now becoming the favoured choice over traditional incandescent bulbs.

Traditionally, Christmas lights used incandescent bulbs, which involve passing an electric current through a thin metal filament until it heats up and produces light. The glass bulb surrounding the filament keeps oxygen in the air away from the hot filament, which would otherwise oxidise and degrade. While they give off a soft, warm light, there are several downsides to incandescent bulbs — the glass and filament can break easily, the bulb tends to get very hot, and a lot of energy is wasted in the form of heat. So while incandescent bulbs are some of the cheapest to buy, they require a lot of electricity to operate.

Did you know? The electricity required to power a standard incandescent bulb over its lifetime costs 5 — 10 times the original purchase price of the bulb and about 90% of that energy is lost as heat.

Thankfully, there is a more energy efficient alternative to traditional bulbs, in the form of the light emitting diode, or LED, Christmas lights. LEDs produce light differently from incandescent bulbs, in that the light, or luminescence is created from an electric field, rather than heat. LEDs are a form of semiconductor, a porous material that can be coaxed into either conducting or not conducting electricity. The semiconductor is impregnated with impurities that create semiconductor junctions. When electrical energy is applied, electrical charge carriers, known as electrons, flow through the resulting electric field and across the semiconductor junctions. The electrons will occasionally move across a low energy area where there are no electrons, known as an electron hole, resulting in the release of energy from the electon in the form of emitted light. The colour of the light produced depends on the materials used for the semiconductor and impurities.

Did you know? The cost to light a Christmas tree with LEDs is less than 20 cents per season, compared to 6 — 10 dollars per season for traditional incandescents.

LED lights have a number of advantages over incandescent bulbs: they are more energy efficient because they don't lose any energy as heat and therefore require much less energy to run; they are safe because they run at cool temperatures, unlike hot incandescent bulbs; they are durable because they're made of plastic and have no breakable glass or filament; their durability and energy efficiency make them more environmentally friendly and easier on the pocketbook, too!

While LED Christmas lights can be a little bit more expensive to buy than incandescent, they eventually pay for themselves in energy savings within a year or two. And while they have often been criticized for a lack of brightness and colour choices in the past, in recent years improvements have been made in the warmth and colour of the light, such that they often look as good or better than incandescent. So if your old strand of traditional Christmas lights finally burns out, look into LED Christmas strands as an eco-friendly replacement. Besides, with the money saved, perhaps you can afford to buy yourself a little something for Christmas.


Article first published December 24, 2008

May Cheng

I am a PhD student in the Department of Cellular and Physiological Sciences at UBC, where I am investigating the electrical properties of cardiac potassium channels. When not in the lab, I'm probably cooking up a storm, immersed in a book, or catching a movie.

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