A tidbit to consider when you are stringing your tree and adorning your home with lights this year (or next): If all of the holiday bulbs sold this year were energy efficient, it would save 700 million kilowatt hours and the equivalent of greenhouse gas emissions from 100,000 cars. Those numbers come from the U.S. government’s ENERGY STAR program, which has certified a number of brands of light strings that it says can last up to 10 times longer and use 70 percent less energy than incandescent strands.

This efficiency can translate into significant savings on a utility bill. An incandescent holiday light typically needs 7 watts of power, versus .04 watts for an LED version.  If