Senate Democrats ditched a plan to cap greenhouse gas emissions and instead laid out plans for a narrow bill that would address the Gulf oil spill and include some energy efficiency measures.

Also dropped from the bill outlined by Senate Majority Leader Harry Reid, D-Nev., was a renewable electricity mandate sought by the wind-power industry.

"A refusal to pass" the mandate "is an attack on every American worker and consumer," said Denise Bode, chief executive of the American Wind Energy Association.

Wind power installations this year have dropped by 54 percent from the 2008 level and 69 percent from 2009, according to the organization.

A Senate committee had approved mandating that 3 percent of electricity be renewable initially and then raise the targets to 15 percent by 2021. The mandates were too low for the wind industry, but they had hoped to include something similar but tougher in a broad energy bill.

The House narrowly passed legislation more than a year ago that would impose emission caps and set up a system for trading carbon-reduction credits, as well as create the renewable power mandates. However, Sen. John Kerry, D-Mass., who was leading Democratic efforts to write a similar bill in the Senate, said it was impossible to get the 60 votes necessary to overcome a filibuster.

Under the House-passed bill, farmers could earn credits through soil-conserving practices or planting trees and then sell the credits on the market to utilities and other emitters that needed them.

However, rural electric cooperatives and coal-dependent utilities such as MidAmerican Energy and Alliant Energy fought the plan, arguing that would lead to major rate increases.

Many farm groups also raised concerns about the impact on production costs and commodity prices.