Waashington ? It’s a bright idea: Get one of the Senate’s biggest skeptics of the causes of global warming to co-sponsor legislation that encourages conservation.

So when Democrats wanted to pass a bill to phase out old-style incandescent light bulbs and require that Americans replace them with more energy-efficient models, they turned to Alaska Sen. Ted Stevens for some GOP support.

The Republican senator jumped at the chance.

“Americans have improved upon nearly all of Thomas Edison’s inventions, and this legislation will encourage a new generation of innovators to advance his greatest accomplishment, the light bulb,” Stevens said in a statement. “Energy efficient lighting will save consumers billions in energy costs and help reduce greenhouse gas emissions.”

If the bill passes and Americans gradually switch out bulbs over the next seven years, the Senate Energy and Natural Resources Committee estimated that annual energy savings would reach $6 billion.

Energy-efficient bulbs could save more than 65 billion kilowatt hours of electricity a year, said Rep. Fred Upton, R-Mich., a House of Representatives co-sponsor of the bill. That’s the equivalent of 80 coal-fired power plants, Upton said.

The legislation requires that light bulbs be 300 percent more efficient by 2020, said Rep. Jane Harman, D-Calif., another House sponsor of the legislation. The bill’s sponsors also would like light-bulb manufacturers to find a way to keep mercury from being released in the manufacture and disposal of the new energy-efficient bulbs.