AskPablo: Green Holiday Lights?
A traditional string of 100 clear 2.5v/170mA lights are available from one online retailer for $13.95 although you can easily find lower-quality ones for less. They are made in China and come with a warning about the presence of lead. When a bulb goes out, the whole string might go dead, although newer strings feature an "always on" design that eliminates this problem. The bulbs are made out of glass and are easily broken. Along with their high energy demand (42.5 Watts) and low efficiency (94% heat) they even present a fire hazard, especially when multiple strings are connected to the same outlet.
LED light strings have traditionally been quite expensive but the price has come down significantly. This year Costco is selling two different sets of 100-bulb LED strings for $7.39 and $8.99. The benefit of the LED lights is that they last 200,000 hours, do not contain glass, do not burn out, and use much less electricity (between 2 and 4 Watts). This also means that they put out much less heat and do not pose as much of a fire hazard.
If you traditionally decorate your house with twenty 100-bulb strings you require 850 W. If you turn your lights on for 6 hours per day this adds up to 5.1 kWh per day. If you put your lights up a month before Christmas you will have used 153 kWh to spread joy into the world, not to mention heat and light pollution. At $0.15/kWh the cost for this would be over $22.
With LED lights you would only use 60 Watts, using 0.36 kWh per day, 10.8 kWh for the month, or only $1.62. For even further savings you could put the lights on a timer and only turn them on for 3 hours per day.
This year LED holiday lights are available at WalMart, Target, Ace, Amazon.com, and many other retailers. Since the price is finally right, perhaps it is time for you to trade in those wasteful old lights and start dreaming of a green Christmas...