If a source of electricity already widely used by some utilities  hydropower or nuclear power, for example  is deemed renewable, it allows utilities to meet the new renewable-energy requirements while doing little to add wind or solar power to the electrical grid. House Republicans tried unsuccessfully last week to have nuclear energy included under the climate bill passed by the House committee.

Environmental groups like the Union of Concerned Scientists, Environment America and the Natural Resources Defense Council say they are frustrated by the increasing elasticity of the word “renewable” in legislators’ hands.

“Usually this is a very political process, and not driven in any way, shape or form by any strict scientific or ecological definition of renewables,” said Nathanael Greene of the N.R.D.C.

But some of the industries that have claimed the renewable mantle argue that they deserve it.

“A banana is renewable  you can grow them forever,” said Bob Eisenbud, a vice president for government affairs at Waste Management, which receives about 10 percent of its annual revenues of $13.3 billion from waste and landfill energy generation. “A banana that goes into garbage and gets burned,” he added, is “a renewable resource and producing renewable energy.”

But environmentalists argue that one of the goals of renewable energy is to cut back on the heat-trapping gases emitted from burning most things, whether fossil fuels or bananas. When there is no fire, there are no emissions. The waste-to-energy technology described by Mr. Eisenbud was not included in the original draft of the climate legislation that received House committee approval, but it was contained in the version that moved out of the committee, thanks to language inserted by Representative Baron P. Hill, Democrat of Indiana. A new $227 million waste-to-energy plant was already planned in northern Indiana, outside his district.

On the Senate side, an effort to get the benefits of the renewable designation for advanced coal-burning technologies failed, however.

Senator Jeff Bingaman, Democrat of New Mexico and chairman of the Senate energy committee, said that if too many new technologies beyond core renewable sources like wind and solar were to be included, “the whole purpose of the renewable electricity standard is defeated.”