The U.S. Congress passed legislation in 2007 requiring general-purpose light bulbs be 30 percent more energy efficient than the standard incandescent bulb. The phase-out will begin with the 100-watt bulb in January 2012.
This means that they must consume less electricity (measured in watts) for the amount of light produced (measured in lumens). Manufacturers will follow suit with the 75-watt bulb in 2013, and 60- and 40-watt bulbs by 2014.
Energy-efficient lighting options include halogen incandescents, compact fluorescent lamps (CFLs) and light emitting diodes (LEDs).
Many consumers are still in the dark regarding new types of light bulbs, how the new laws affect consumers and what to expect when the changes take effect. Here's a brief rundown of common questions:
Q: Doesn't this move cost me money?
A: Upfront, yes. A CFL is more expensive than an incandescent bulb, but it'll likely pay for itself inside of nine months in terms of reduced energy usage, according to the U.S. Department of Energy.
Upgrading 15 incandescent light bulbs in your home could save you about $50 per year.
An incandescent costs the average consumer about $4.80 to operate, compared to about $3.50 to operate a halogen incandescent bulb, $1.20 to operate an ENERGY STAR CFL bulb, and $1.00 to operate an ENERGY STAR LED bulb, all of which produce the same amount of light.
Q: Will every bulb replacement save money?
A: Not necessarily. There are some areas where the extra cost of a CFL may never be repaid, typically those that see bulbs used relatively infrequently such as little-used closets and attics.
Q: Do the new laws affect all incandescent bulbs?
A: No. Various specialty bulbs are exempt, including appliance bulbs, heavy-duty bulbs, colored lights, three-way bulbs, plant lights, bug lights and others.
Q: Will the newer bulbs fit my lighting fixtures or work with my lamp shades?
A; Most older lighting fixtures accept the newer bulbs, and the newer energy-saving bulbs will work with conventional, medium screw-based sockets. Some CFLs are now available in the familiar "bulb" shapes.
Q: Can I use dimmers?
A: Most CFLs are not compatible with all existing dimming circuits, and some pose a fire hazard when used in such circuits. But, more dimmable CFLs are expected to become available.
Incandescent and halogen bulbs tend to work with dimmers, said Mary Beth Gotti, manager of the GE Lighting Institute.
Q: Can I get in trouble if I continue to use old bulbs?
A: No. The legislation isn't an actual ban. The new standards apply to lighting manufacturers and wholesalers, who won't be allowed to sell bulbs that don't meet the minimum efficiency requirements.
"You don't have to throw away a light bulb that's in your home," said Jen Stutsman, a spokeswoman with the U.S. Department of Energy. "If a retailer has older bulbs on their shelves beyond the deadline, they're allowed to sell them."
Q: Is it dangerous to dispose of CFL bulbs?
A: Each CFL contains a trace amount of mercury and should not be placed into the trash, said Kelly Cunningham, outreach director at the California Lighting Technology Center at University of California at Davis.
If the CFL is broken, sweep up the parts with a broom and put it aside. Some retailers provide CFL recycling drop-off, and local waste management agencies offer disposal or recycling options.
Q: How can I make sure I'm buying a quality product?
A; Choose only a CFL certified by a nationally recognized testing and certification organization.
"It's up to us to work with the GEs and the Phillips of the world to ensure their products meet these requirements," said Terry Drew, director of energy efficiency and sustainability at CSA International, which tests and certifies light bulbs.
ENERGY STAR qualified CFLs have a minimum two-year warranty.
Q: Can I turn CFLs on and off frequently?
A: Doing so can shorten its life. ENERGY STAR requires bulbs to hold up to frequent switching. But it's best to place them in light fixtures used the most and are on for at least 15 minutes at a time.