The traditional incandescent light bulb as you know it soon will be extinct. It’s probably not going to happen tomorrow or even next year, but there is no doubt that the 125-year-old technology that Thomas Edison created will be largely gone before you know it.

In some ways, the slow death of the bulb has already begun. When President Bush signed the energy bill last December, ­buried in the legislation was a provision that phases out incandescent light bulbs over the next four to 12 years in favor of more energy-efficient technologies.

Incandescent has had a good run. The technology uses an electrical current that heats a filament to produce warm, high-quality lighting that is very flattering, says Mary Beth Gotti, manager of GE’s Lighting and Electrical Institute in Cleveland. It’s cheap, effective, and readily available. “It also comes in different shapes and sizes and is dimmable,” Gotti adds.

However, the traditional light bulb is an energy hog, and this is the reason for its demise. Compact fluorescent lighting (CFL), the likely successor to incandescent, is a good, energy-efficient option that has come a long way from the days when long tubes produced an unappealing buzz and an undesirable bluish hue. Newer spiral-shaped bulbs offer better performance. With light outputs of 40 to 80 lumens per watt, they’re extremely efficient. ToolBase Services, the technical information resource of the NAHB Research Center in Upper Marlboro, Md., says fluorescent bulbs last up to 10 times longer than incandescent and use 50 percent to 80 percent less energy.

But now a newer technology, light-­emitting diode (or LED), is emerging, and manufacturers say it offers more promise than CFLs. LED fixtures use a semiconductor to convert electricity into light. ToolBase says the bulb incorporates a built-in driver (like a fluorescent ballast) or uses a plug-in transformer that allows portable fixtures to run on standard AC power. Bulbs generate about 20 to 30 lumens per watt.

LEDs aren’t exactly new—they’ve been around since the 1960s—but manufacturers say they have made technological advancements that will propel the technology into consumer consciousness. Zachary Gibler, chief business development officer for New York–based LED manufacturer Lighting Science Group Corp., has even proclaimed 2008 “the year of the LED light.” Why the confidence? LEDs are “now at a point where they deliver comparable performance to incandescent,” Gibler says. “They can put out the same amount of light, the color temperature is similar, and the color rendering is now close to incandescent.”

“In the past, LEDs were synonymous with harsh, blue tints, but LED technology has grown considerably,” says Jim Jones, product manager of Kichler Lighting in Cleveland. “The LED chips Kichler uses emit a soft, white light that adds warmth and ambience.”

ToolBase agrees that LEDs are more efficient and do not produce heat like ­incandescent bulbs. Moreover, they “last considerably longer than incandescent or fluorescent lighting” and “don’t typically burn out like traditional lighting, but rather gradually decrease in light output.”

Lighting designers admit that LEDs have come a long way, but some say the technology still has some growing to do. Naomi Miller, principal of Naomi Miller Lighting Design in Troy, N.Y., says the technology still isn’t mature enough. “The color rendering is not very good, and many flicker during operation with a dimmer,” she says. Miller admits that LEDs are great for colored lights, but she says they’re inconsistent for white light and don’t generate as many lumens as manufacturers claim. “The technology is evolving very fast,” but it’s still about five years away from perfection, she says.