LEDs (or light-emitting diodes) are small sources of light that work when the movement from electrons illuminate semiconducter material. This longer lasting technology is usuallu found in traffic lights and exit signs, but now consumers can find LED light bulbs and even Chistmass lights. Companies like GE are working to make LED technology more affordable and practical for homes. The Department of Energy estimates that rapid adoption of LED lighting in the U.S. over the next 20 years can reduce lighting electricity bu 33% by 2027.