Sens. Lisa Murkowski (R-Alaska) and Joe Manchin (D-W.Va.) on Thursday introduced a long-awaited energy package that's shaping up to be the best chance this year for passing legislation to expand the use of cleaner forms of energy.

The American Energy Innovation Act would touch nearly every aspect of the energy industry, incorporating more than 50 bills advanced by the Senate Energy and Natural Resources Committee.

Senate Majority Leader Mitch McConnell (R-Ky.) took steps Thursday to bring the more than 550-page bill to the floor as early as next week.

"This bill is our best chance to modernize our nation's energy policies in more than 12 years," Murkowski said in a statement. "By working together to pass it into law, we can promote a range of emerging technologies that will help keep energy affordable even as it becomes cleaner and cleaner."

The package would promote research in up-and-coming renewables like geothermal and wave technology while shoring up supplies of minerals needed for the batteries to support long-term use of wind and solar.

It also includes efforts to bolster the capture of carbon pollution, including from the coal and natural gas sector, as well as research to expand nuclear energy.

However, some portions of the bill, like those dealing with mining, as well as fossil fuels, may prove too controversial for some Democrats. And it's already being criticized by environmental groups for doing too little to address climate change.

The package does not set any specific carbon reduction targets, though committee staff said it is expected to reduce emissions.

The legislation's research and development portions, as well as its energy efficiency measures, have some overlap with bills still being drafted in the House that would commit the U.S. to carbon neutrality by 2050.

A committee aide told reporters the bill is an energy bill, with provisions that are very important for dealing with climate change.

The aide acknowledged the bill was not sufficient to address climate change, but called it a downpayment on climate legislation that is mainly focused on energy innovation.

The legislation contains elements of bills sponsored or co-sponsored by 60 senators from across the political spectrum, as well as some House legislation that has already been sent to the Senate.

Senate aides expressed optimism that the House would be willing to work together on the legislation. Speaker Nancy Pelosi's (D-Calif.) office declined to comment on the legislation.

The bill includes a number of energy efficiency measures, extending a program to weatherize homes, offering grants to retrofit buildings, and requiring the government to extend its own energy reduction targets while adding new reductions for water use.

But the bulk of the bill centers on boosting new and developing technologies, including ways to make cars and trucks more fuel efficient, as well as methods to make manufacturing processes greener.

It also includes a number of cybersecurity and grid modernization efforts to prevent electric grids from being hacked by adversaries.

But some portions of the bill may make it tough to get Democratic support, particularly those dealing with mining for minerals needed to make batteries.

The Sierra Club referred to that portion of the bill as an "egregious non starter" that would "vastly expand the permitting of destructive mining operations, as well as an expansion of fracked gas exports."

That portion of the bill would require the Department of the Interior to create a list of critical minerals, encouraging the government to "complete federal permits efficiently, without compromising environmental review," according to a bill summary.

"We still give mining companies - many foreign owned -- a sweetheart deal, but leave taxpayers on the hook for cleaning up the toxic messes at thousands of abandoned mines across the West," Sen. Tom Udall (D-N.M.) said in a statement to The Hill.

"I have serious concerns with the energy bill provision that gives the mining industry a new break on their permitting process for massive mining projects, which could have grave consequences for public health and the environment."

That may raise red flags after the Trump administration has pushed to designate uranium as a critical mineral, opening the possibility of mining the substance near the Grand Canyon, despite objections from Democrats that the mineral is already widely supplied by U.S. allies.

The legislation spurred mostly negative reactions from major environmental groups.

"At a time when we need to rapidly transition away from dirty fossil fuels to 100 percent clean energy, this bill points us in the wrong direction," Sierra Club legislative director Melinda Pierce said in a statement.

"Innovation and R&D of course have a role, but what is urgently needed right now goes beyond research that will have payoffs far down the road. We need action on deploying the proven clean energy technologies that are reducing emissions today."

Meanwhile, the Union of Concerned Scientists called the bill a heartening effort, but warned that the portions on nuclear energy include research for "designs that could use nuclear weapon-usable fuels and involve reprocessing of their spent fuel, needlessly increasing risks of domestic terrorism and nuclear proliferation."

The union, like the Sierra Club, argued that the U.S. should be focused on providing tax credits to clean energy sources already on the market.

"Electric vehicles, clean energy technologies like wind and solar power, and energy storage technologies that facilitate a cleaner electricity grid are all commercially available. Furthermore, clean energy tax credits have been the most effective federal policy tool for incentivizing deployment of these technologies, but many of these incentives are phasing down or are expiring," the group said in a statement.

- Updated at 4:45 p.m.