WINCHESTER, VA. - The last major GE factory making ordinary incandescent light bulbs in the United States is closing this month, marking a small, sad exit for a product and company that can trace their roots to Thomas Alva Edison's innovations in the 1870s.

The remaining 200 workers at the plant here will lose their jobs.

"Now what're we going to do?" said Toby Savolainen, 49, who like many others worked for decades at the factory, making bulbs now deemed wasteful.

During the recession, political and business leaders have held out the promise that American advances, particularly in green technology, might stem the decades-long decline in U.S. manufacturing jobs. But as the lighting industry shows, even when the government pushes companies toward environmental innovations and Americans come up with them, the manufacture of the next generation technology can still end up overseas.

What made the plant here vulnerable is, in part, a 2007 energy conservation measure passed by Congress that set standards essentially banning ordinary incandescents by 2014. The law will force millions of American households to switch to more efficient bulbs.

The resulting savings in energy and greenhouse-gas emissions are expected to be immense. But the move also had unintended consequences.

Rather than setting off a boom in the U.S. manufacture of replacement lights, the leading replacement lights are compact fluorescents, or CFLs, which are made almost entirely overseas, mostly in China.

Consisting of glass tubes twisted into a spiral, they require more hand labor, which is cheaper there. So though they were first developed by American engineers in the 1970s, none of the major brands make CFLs in the United States.

"Everybody's jumping on the green bandwagon," said Pat Doyle, 54, who has worked at the plant for 26 years. But "we've been sold out. First sold out by the government. Then sold out by GE. "

Doyle was speaking after a shift last month surrounded by several co-workers around a picnic table near the punch clock. Many of the workers have been at the plant for decades, and most appeared to be in their 40s and 50s. Several worried aloud about finding another job.

"When you're 50 years old, no one wants you," Savolainen said. It was meant half in jest, but some of the men nod grimly.