The incandescent bulb is about to become obsolete is lost on the vast majority of the public. The phase-out begins in three years as part of the energy bill signed in 2007. They will be edged out by LEDs. So light bulb makers have to revamp some plants, shutter others, and invest enormous sums of money in preparation for a technological shift.

Incandescent bulbs, invented by Thomas Edison more than 120 years ago, brighten a room by heating a metal filament in a vacuum, but waste large amounts of heat. Compact fluorescent bulbs contain a gas that reacts with electricity to create invisible ultraviolet light. When that light hits material inside the bulb, it is converted into ordinary light. LEDs emit very little heat, are about 40 percent more efficient, and can last for more than 50,000 hours. For instance, a typical 100-watt bulb be replaced by one that provides the same amount of light with 72 watts.

Osram Sylvania, one of the world's largest bulb producers, commissioned a survey to find out if the public agreed, only to find out 80% of Americans don't know the light bulb, as we know it, is on the way out.

Major bulb manufacturers and retailers are meeting in Dallas this week to find ways to incorporate LEDs into more products, but have been in transition mode for years. General Electric has closed lighting plants in Brazil, Mexico, and the United States, and Osram Sylvania is modifying existing plants. The European Union will start phasing out incandescent bulbs this September.

Specialty incandescent bulbs - such as those used in appliances - will be available on a limited basis. The cost of switching to LEDs and compact fluorescents could be a jolt to some consumers. Royal Philips Electronics introduced a line of LEDs in Europe last year for about $90. General Electric's base LED bulb sells for about $35 to $40.

Prices will come down as technology improves, said Charlie Jerabek, president and chief executive of Osram Sylvania. And the new bulbs do eventually pay off, economically and in efficiency.

Americans keep about 73 million lights on every day for a period of between four and 12 hours, with about 28 million powered by energy-efficient bulbs, according to the Department of Energy. The new lighting standards coming online are expected to lower consumers' annual electricity bills by $13 billion in 2020.