Dear EarthTalk: What are the greenest light bulbs to use? I hear there has been a lot of backlash against compact fluorescents because they contain mercury.--Peter Roscoe, Hershey, PA
Just a decade ago, incandescent bulbs were just about the only game in town, despite their inefficient use of electricity to generate light and their primitive technology that had not changed since being invented some 125 years ago. But now that is all changing fast, with phase-outs of incandescents going on in Australia, Brazil, Venezuela, Switzerland and the European Union, with Argentina, Russia, Canada and the U.S. following suit shortly. The U.S. passed legislation in 2007 to increase the efficiency of light bulbs sold in the U.S. by 25 percent or more by 2014, and then by as much as 60 percent more by 2020.
For decades, those concerned with energy savings have been touting the benefits of compact fluorescent lamps (CFLs) over incandescents. CFLs use only one-fifth of the electricity of incandescents to generate the same amount of light, and they can last six to 10 times longer. But CFLs' cooler color and inability to be dimmed have made them less desirable. Another hindrance to the widespread adoption of CFLs has been their higher cost (though most consumers would save plenty in energy costs over the life of a bulb). Also, CFLs contain mercury, a dangerous neurotoxin that is released when the bulbs break. And once CFLs do burn out they must be disposed of properly to avoid releasing mercury into the environment.
Given the issues with CFLs, LEDs (short for light emitting diodes) are beginning to come on strong. These highly efficient bulbs don't generate heat like incandescents (which helps to keep air conditioning costs down as well) and can last five times longer than CFLs and 40 times longer than incandescents. Tiny LED bulbs have been around for years in specialized applications (such as stadium scoreboards), but lighting engineers got the idea to cluster them and use reflective casings to harness and concentrate their light for residential use. In recognition of the LED's potential, the U.S. Department of Energy (DOE)...