The giant policy bill muscled through Congress by Republicans is poised to remake American energy by slashing tax breaks for wind and solar power and electric cars while maintaining some federal support for sources such as nuclear reactors and geothermal plants.

The legislation, which carries President Donald Trump’s domestic policy agenda, provides a boost to fossil fuels and dismantles many of the biggest actions the federal government has ever taken to fight climate change, even as scientists warn that rising temperatures are creating acute dangers from extreme heat, deadly wildfires, crop failures and floods.

Yet there is still uncertainty about how changes from the bill will play out.

Solar farms could still get built even without federal subsidies, although they could be more expensive and more likely to use components made in China than in the United States. Other industries that get favorable treatment, such as technology that captures carbon dioxide, could nevertheless struggle.

Here’s a rundown of the energy winners and losers in the bill, which was finalized by the House on Thursday. Trump was set to sign the bill Friday.

Q: Who loses?

A: Wind and solar power.

The bill would quickly phase out tax credits for wind and solar power, two of the fastest-growing sources of electricity in the United States. Both industries could shrink but are unlikely to vanish, experts said.

Previously, companies building wind and solar farms could qualify for a tax credit worth at least 30% of costs if they began construction before 2034. Under the new law, projects would probably need to start construction within the next year — roughly by next July — to have the best chance of getting the full credit. After that, the subsidy becomes harder to get and swiftly expires.

Developers are now racing to stockpile panels and equipment so they can beat that deadline. But hundreds of planned projects could get canceled or become pricier. All told, the amount of wind and solar capacity expected to come online by 2035 could fall by half, some analysts predict.

Still, in places such as the breezy Great Plains or sunny Southwest, building wind and solar farms will remain one of the easiest ways to squeeze more electrons onto the grid, even without subsidies. Electricity demand is surging, and there is a multiyear backlog for new natural gas turbines. So utilities and tech companies may keep buying renewable energy, albeit at higher costs.

“We’ll continue to build out renewables, but we’ll build out a lot slower,” said David Carroll, chief renewables officer for ENGIE North America, a major power plant developer. The changes, he added, “are ultimately going to hurt consumers, because it’s going to raise prices.”

The renewable industry did prevail on Senate Republicans such as John Curtis of Utah and Lisa Murkowski of Alaska to make a few last-minute changes. A contentious tax on future wind and solar projects got stripped from the bill. And solar leasing companies, which have made rooftop systems widely accessible, are no longer barred from tax credits, as they were in an earlier draft.

Q: Who are the possible winners?

A: Nuclear, geothermal and batteries.Although Republicans slashed support for wind and solar, they preserved until 2036 a major Joe Biden-era tax credit for companies that build other emissions-free power technologies such as nuclear reactors, hydroelectric dams, geothermal plants and battery storage. These sources can run at all hours, unlike wind and solar.

Trump has a long-standing animus for wind turbines and solar panels, which he calls “ugly” and inefficient. Energy Secretary Chris Wright supports more nuclear power in addition to championing fossil fuels.

Experts say that new nuclear and geothermal plants could help tackle climate change, because they don’t generate greenhouse gases that warm the planet. But they will take time to develop and face challenges in scaling up, including high costs.

The tax credit could also still be claimed by anyone adding large batteries to the grid, something that companies are increasingly doing in California and Texas to back up wind and solar plants and prevent power outages.

Yet China currently dominates supply chains for batteries and Congress added complex restrictions to the credits that bar recipients from having ties to “prohibited foreign entities” such as China. The Treasury Department would need to clarify those rules, and some worry that the restrictions are so complicated that the credits could end up being unusable for many projects.

“There’s a ton of uncertainty around these new rules,” said Advait Arun, a senior associate for energy finance at the Center for Public Enterprise, a nonprofit. “It’s premature to call this bill a victory” for nuclear and geothermal power, he said.

Q: Are there other losers?

A: The bill is likely to put a major dent in the U.S. electric-car market by repealing federal incentives that have been critical to its growth.

Tax credits worth up to $7,500 to buy new or used electric cars will end by Sept. 30 under the new bill. (Those credits were previously available until 2032.) Also expiring is a loophole that allowed companies to pass tax savings on to people who leased vehicles. Incentives for businesses to buy electric trucks will vanish.

Electric cars won’t disappear from dealerships, but they will get pricier. At the same time, the Trump administration is rolling back federal fuel-efficiency rules and has sought to block a California plan intended to force automakers to sell more zero-emissions vehicles.

Those factors together could mean tens of millions fewer electric cars sold over the next decade than previously expected, according to the Rhodium Group, a research firm.

That could leave the United States falling behind China and Europe, where electric vehicles are spreading rapidly. At the same time, some auto executives believe EVs will eventually displace gasoline-powered cars and say they will keep investing in the technology.

“We are in a global competition with China, and it’s not just EVs,” Ford CEO Jim Farley said recently at the Aspen Ideas Festival. “And if we lose this, we do not have a future at Ford.”

When Democrats in 2022 created and expanded a slew of federal tax breaks for EVs, solar panels, wind turbines, batteries, they designed them to encourage companies to use components made in the United States. That spurred a manufacturing boom, including solar-panel glass recyclers in Georgia and EV assembly lines in Kentucky.

The new law could derail many of those factories.

The old tax credit for solar power, for instance, offered developers a bonus if they used domestic panels. With that credit expiring by 2027, some companies looking to install solar may now prefer to use cheaper components from China, a manufacturing powerhouse.

“This bill will lead to a flood of Chinese imports, hurting U.S. manufacturing jobs and investments,” said Mike Carr, executive director of the Solar Energy Manufacturers for America, a trade group.

The EV tax credit was likewise available only for domestically made vehicles.