The Ins and Outs of CFLs

When Thomas Edison sparked light from a bit of carbonized sewing thread in 1879, could he have imagined that 130 years later the same basic technology would still be keeping the world out of the dark?
 
By any measure, Edison’s incandescent lightbulbs have had a good run. But by 2012 we will phase out this time-tested technology in the United States, in favor of a more efficient generation of lightbulbs.
 
As a result, store shelves increasingly will be lined with more energy-efficient alternatives, the bulk of which will be compact fluorescent lightbulbs (CFLs). You have probably seen these corkscrew-shaped bulbs by now, and may have even outfitted your home with them. But what makes them so much more efficient?
 
CFLs are made of two components: a gas-filled tube—the “swirly” part—and an electronic ballast—the plastic base. Light gets produced when mercury molecules, contained in argon or neon gas in the bulb, are excited by an electric current. These molecules then react with a phosphor coating on the inside of the tube, which creates light. With a white coating, you get white light; with a red coating, red light, etc.
 
Incandescent bulbs, on the other hand, produce light by running a current through a tightly coiled metal filament, typically tungsten. Atoms in the filament produce light when heated to around 4,000 degrees Fahrenheit. As a result, about 90% of the power consumed by a typical incandescent lightbulb is emitted as heat, as anyone who has changed a hot bulb knows well. CFLs, in comparison, produce 75% less heat.
 
Benefits of CFLs go beyond cooler bulbs: A 75-watt incandescent lightbulb will burn out after about 40 days of continuous use, whereas a CFL can keep going for a full year; CFLs require one-third less energy than incandescent bulbs, which saves roughly $30 in energy costs over the bulb’s lifetime, according to ENERGY STAR.
 
As CFL technology advances, new bulb and light quality options will expand its use to a wider range of applications. Installation guidelines should be followed to ensure CFLs  perform correctly. 
 
For example, not all CFLs perform well on dimmable switches and three-way fixtures, so be sure to check the packaging to see if the bulb’s ballast design matches your needs. You’ll also get more value if you leave CFLs on for 15 minutes or longer; switching them on and off can shorten their lifespan.
 
Exterior lighting offers a great place to use CFLs, but if you live in a colder climate, look for specially designed cold-weather versions—standard CFLs may not work well below 40° F.
 
To learn about the latest ways you can use CFLs to make your home more energy efficient, visit ENERGY STAR at www.energystar.gov.

Sources: ENERGY STAR, General Electric Company, U.S. Department of Energy; Scott Gates writes on consumer and cooperative affairs for the National Rural Electric Cooperative Association, the Arlington, Va.-based service arm of the nation’s 900-plus consumer-owned, not-for-profit electric cooperatives