A new law is aimed at turning the lights out on Thomas Edison’s 131-year-old bulb that consumers have come to associate with the warm glow of home.

As of Jan. 1, the traditional 100-watt and 150-watt A19 incandescent light bulb is no longer sold in California. A year from now, the energy waster will be out of business nationwide.

In 2013, the familiar 75-watt incandescent also will be history. (California will shoo them off of store shelves one year earlier.) And in 2014, Americans will wave good-bye to their beloved—albeit energy-inefficient—60- and 40-watt A-shaped incandescents.

The resulting switch to more efficient compact fluorescent lamps (CFLs) or to the brand-new high-efficacy halogens that manufacturers have introduced in response to the “light bulb law” within the Energy Independence and Security Act of 2007 will mean considerably steeper prices—in the $2-per-bulb range—versus the 50-cent incandescent. But other than that, for many builders, the shift will barely register because—for now—only the bulbs, and not the fixtures, are required to change.

“It’s not that hard of a change to make for recessed lighting, which is most of the indoor lighting that we build into homes,” says Jim Bayless, owner of GreenBuilt Construction in Folsom, Calif. 

In fact, estimates the National Electrical Manufacturers Association, about a quarter of the light bulbs sold in America are CFLs, and many pros long ago embraced them. Those who haven’t, advises Larry Weinstein, president of design/build firm DBS-Shared Solutions America in San Diego, should make the switch.

“Architects and contractors for the most part are hurting right now,” he reasons. “Those who are wise enough to realize there’s a substantial market in energy-efficient new homes are doing very well.”

Derek Greenauer, program manager for D&R International, a Silver Spring, Md.-based energy-efficiency consulting firm, agrees. “If builders can get up to speed on LEDs [light-emitting diodes] and technology and the new choices they’ll have for lighting homes, they can kind of ride that green wave to set a particular builder apart from competitors.”

Builders and homeowners who will grieve the loss of the familiar A-shaped incandescent, says Weinstein, will do so only because “they don’t know any better.”

What they might not know is that CFLs—the most likely immediate replacement bulb both for built-in residential lighting and for portable luminaires like table lamps—last for around five years and use 75% less energy than traditional incandescents, which burn out after about seven months of normal use. CFLs also cost about four times more.

What they almost certainly don’t know is the difference between a lumen—a measure of light output that the government is requiring bulb boxes to display starting in July—and a watt, the consumer’s comfortable gauge of how bright a light bulb will burn.

An example: The old 60-watt incandescent bulb produces 800 lumens. So a builder or homeowner who wants to replace a 60-watt bulb with a similar but more energy-efficient alternative should choose a CFL, high-efficacy halogen, or LED that produces 800 lumens. That number will be displayed on the package’s required new Lighting Facts label (see "Reading the Label," page 2).

“The big challenge,” says Hampton Newsome, an attorney and spokesman for the Federal Trade Commission, “is to help people understand that when they’re looking for the light the bulb produces, look at lumens.”

So it’s a good thing the phase-out is staggered over three years, says Peter Soares, director of consumer product development for Philips. “It will give consumers time to understand the legislation,” he says.

And it could take some time. “There hasn’t been much consumer education about light bulbs in a long, long time,” notes Terry McGowan, director of engineering for the American Lighting Association[http://www.americanlightingassoc.com/]. “The fact is that the consumer likes to make decisions right at the shelf and gets confused with all these labels and lamps. I don’t know what they’ll do.”

His prediction: “Any time there’s change, there’s a little bit of craziness.” Indeed, some are expecting consumers to make a run for incandescent light bulbs as Jan. 1, 2012, approaches, stockpiling them like milk and bread before a snowstorm.