Decorating your home with string lights can be a festive way to bring joy to your home and neighborhood. When shopping for new lights, consider ones that are LED and Energy Star qualified. They use a fraction of the energy of traditional lights and can last up to 10 times longer. So while the investment up front may be a little more, over time you'll save money and energy. If every string of lights sold in the U.S. were Energy Star qualified, our country would save $80 million on electricity in one year.