THOMAS EDISON WOULD BE PROUD: NEW BULB MAY LAST FOR 20 YEARS

Its developers are calling it the biggest breakthrough since Thomas Edison got a filament to glow without interruption: a light bulb that works by radio signals and lasts up to 20 years.

The new electronic bulb - which needs one-quarter of the energy that standard bulbs use - was introduced Monday at a meeting here of the Edison Electric Institute, an association of utility companies.

Its developers say the electronic bulb gives off as much light as an incandescent bulb and fades as it gets older, instead of going out. It will fit in most sockets. It can also be dimmed.

The drawback is the cost - $10 to $20 each when it reaches the market early next year, compared with about $2 for an ordinary 150-watt bulb.

"It's the first major change in what we know as the incandescent light bulb since Edison invented the bulb" in 1879, said Stan Hulett, a spokesman for Intersource Technologies of Sunnyvale, Calif., which helped develop the bulb.

Intersource said the bulb lasts between 15,000 hours and 20,000 hours - or 10 to 14 years if used four hours a day, which is typical in homes. Standard incandescent bulbs last 750 to 1,500 hours, or six months to a year.

Company president Pierre Villere said the biggest problem will be changing the minds of people who are used to replacing light bulbs.

"It's truly a lighting appliance," Mr. Villere said. "You buy it once, you install it in a socket and in a home environment it's good for 10 or 20 years."

The electronic bulb uses a magnetic coil to generate a radio signal that mixes with the same gas used in conventional fluorescent lamps. A plasma is formed, making the phosphor coating on the inside of the glass glow.