(CNN) Sen. Tina Smith of Minnesota confirmed to CNN that Democrats are developing a replacement for the clean electricity program in their sweeping economic package. The program will likely be dropped from the bill after opposition from Sen. Joe Manchin of West Virginia, CNN reported Friday.
After months of negotiating on the program, Smith said Manchin recently informed her that he wouldn't support the program, which is also referred to as the Clean Electricity Performance Program, or CEPP. The program would give utilities federal grants to increase their share of electricity from clean sources and penalize those who fail to increase their clean electricity portfolios.
"He told me last week he just didn't think he could get there on the clean electricity program," Smith told CNN. "But rolling back the CEPP -- which is a foundation of the President's action plan -- that's a huge concession. The question on my mind is what are we going to do instead?"
The clean energy program along with clean energy tax credits would have accounted for the vast majority of Biden's target for the US to cut its greenhouse gas emissions by 50-52% relative to 2005 levels by 2030.
Smith told CNN she's still actively talking to Manchin and other senators about alternatives for how Congress can reduce greenhouse emissions to meet Biden's goal.
"We have to continue to have these conversations and I can't point to anything specific that he's offered," she said of Manchin, who has been critical of the clean energy program since its drafting.
Manchin spokeswoman Sam Runyon told CNN in a statement Friday that the senator "has clearly expressed his concerns about using tax payer dollars to pay private companies to do things they're already doing. He continues to support efforts to combat climate change while protecting American energy independence and ensuring our energy reliability."
Democrats are also running out of time to clinch a deal -- much less pass a bill -- that addresses the climate crisis before global leaders meet at a pivotal UN climate change conference in Glasgow at the beginning of November. The international community is looking to see whether Biden can deliver on his climate commitments.
"I think it's better if we pass something but second best would be that we agreed to something," Democratic Sen. Brian Schatz of Hawaii told CNN.
Instead of the clean energy program, senators are exploring levying a fee on carbon, Smith said, although it's unclear if Manchin will support that. Another potential option is boosting the amount of money in a clean energy tax credit package currently being developed by Senate Finance Chairman Ron Wyden of Oregon.
"The bill produced by the Finance Committee is going to be responsible for 73% of the emission reductions in the next 10 years," Wyden told CNN, saying the structure of his tax credits promises increased tax savings to companies the more they reduce carbon emissions.
Still, Wyden's tax plan is different from the one produced by House Ways and Means Chairman Richard Neal of Massachusetts, something House and Senate Democrats will have to work out in the coming weeks.
But Smith told CNN she thinks clean energy tax credits alone won't accomplish the scale of emissions reductions needed.
"That will be a very important part of our solution, but I don't think they will be enough," Smith said.
Smith has been a longtime champion of the clean energy program and has been working on it for several months, billing it as a way to encourage utilities to decarbonize, without mandating that they switch to clean electricity.
The transportation and electricity sectors emit the most greenhouse gases, according to the Environmental Protection Agency.
"Clean electricity ends up being a catalyst for an entire clean economy," Leah Stokes, senior policy advisor at climate group Evergreen Action and associate professor of political science at the University of California, Santa Barbara, told CNN recently. "It turns out we can use clean electricity to clean up our transportation, our buildings and even part of heavy industry."