A bipartisan pair of senators pushing energy-efficiency legislation said the changes baked into the latest version introduced Thursday has a better chance than ever of clearing the upper chamber.

Sens. Jeanne Shaheen, D-N.H., and Rob Portman, R-Ohio, added 10 bipartisan amendments to the text of the latest version of their energy-efficiency bill, which, in some form, dates to the last Congress. Doing so allowed the senators to pick up more Republican co-sponsors, leaving the bill's architects confident they have 60 votes.

The new version of the bill includes some long-sought Republican goals, a GOP aide told the Washington Examiner. Chief among them is a measure spearheaded by Sens. John Hoeven, R-N.D., Joe Manchin, D-W.Va., Johnny Isakson, R-Ga., and Michael Bennet, D-Colo., that would repeal a requirement that federal buildings get all their energy from non-fossil fuel sources by 2030.

Whether Senate Majority Leader Harry Reid will take it up is another issue. The Nevada Democrat may well be snake bitten by the last attempt to push the bill, when Sen. David Vitter, R-La., pushed an Obamacare-related amendment that compelled Reid to yank the legislation from the floor last fall.

The bill itself is fairly tame, and has the backing of industry, business, labor and environmental groups. It would direct the federal government to reduce energy costs, establish voluntary efficiency codes for new buildings, enhance workforce efficiency training and create incentives for manufacturers to make efficiency upgrades. All told, the American Council for an Energy-Efficient Economy predicts it would save $16.2 billion and create 192,000 jobs by 2030.

But because it's the first substantive energy bill to reach the Senate floor since 2007, it's become a magnet for controversial amendments.

Shaheen and Portman are still seeking an outside agreement on amendments, though it's not clear if they'll be able to deliver something to Reid's liking. GOP aides say he has rejected proposals from Republican leadership in the past that would have called for votes on approving the Keystone XL pipeline and whether the Environmental Protection Agency should regulate greenhouse gas emissions.