The Senate’s Harsh Compromise on Clean Energy Tax Credits, Explained

After more than three days of stops and starts on the Senate floor, Congress’ upper chamber finally passed its version of Trump’s One Big Beautiful Bill Act Tuesday morning, sending the tax package back to the House in hopes of delivering it to Trump by the July 4 holiday, as promised.

An amendment brought by Senators Joni Ernst and Chuck Grassley of Iowa and Lisa Murkowski of Alaska that would have more gradually phased down the tax credits for wind and solar rather than abruptly cutting them off was never brought to the floor. Instead, Murkowski struck a deal with the Senate leadership designed to secure her vote that accomplished some of her other priorities, including funding for rural hospitals, while also killing an excise tax on renewables that had only just been stuffed into the bill over the weekend.

The new tax on wind and solar would have driven up development costs by as much as 20% — a prospect that industry groups said would “kill” investment altogether. But even without the tax, the Senate’s bill would gum up the works for clean energy projects across the spectrum due to new phase-out schedules for tax credits and fast-approaching deadlines to meet complex foreign sourcing rules. While more projects will likely be built under this version than the previous one, the basic outcomes haven’t changed: higher energy costs, project delays, lost jobs, and ceding leadership in artificial intelligence and manufacturing to China.

"This bill will hit Americans hard, terminating credits that have helped families lower their energy and transportation costs, shrinking demand for American-made advanced energy technologies, and squeezing new domestic energy production at a time of rising demand and prices,” Heather O’Neill, the CEO and president of the trade group Advanced Energy United, said in a statement Tuesday. “The advanced energy industry will endure, but the downstream effects of these rollbacks and punitive policies will be felt by American families and businesses for years to come.”

Here’s what’s in the final Senate bill.

Special rules for wind and solar

The final Senate bill bifurcates the previously technology-neutral tax credits for clean electricity into two categories with entirely different rules and timelines — wind and solar versus everything else.

Tax credits for wind and solar farms would end abruptly with no phase-out period, but the bill includes a significant safe harbor for projects that are already under construction or close to breaking ground. As long as a project starts construction within 12 months of the bill’s passage, it will be able to claim the tax credits as originally laid out in the Inflation Reduction Act. All other projects must be “placed in service,” i.e. begin operating, by the start of 2028 to qualify.

That means if Trump signs the bill into law on July 4, wind and solar developers will have until July 4 of 2026 to “start construction.” Otherwise, they will have less than a year and a half to bring their projects online and still qualify for the credits.

Meanwhile, all other sources of zero-emissions electricity, including batteries, advanced nuclear, geothermal, and hydropower, will be able to continue claiming the tax credits for nearly a decade. The credits would start phasing down for projects that start construction in 2034 and terminate in 2036.

Thorny supply chain restrictions

While there are some potential wins in the bill for clean energy development, many of the safe harbored projects will still be subject to complex foreign sourcing rules that may prove too much of a burden to meet.

The bill requires that any zero-emissions electricity or advanced manufacturing project that starts construction after December of this year abide by strict new “foreign entities of concern,” or FEOC rules in order to be eligible for tax credits. The rules penalize companies for having financial or material connections to people or businesses that are “owned by, controlled by, or subject to the jurisdiction or direction of” any of four countries — Russia, Iran, North Korea, and most importantly for clean energy technology, China.

As with the text that came out of the Senate Finance committee, the text in the final bill would phase in supply chain restrictions, requiring project developers and manufacturers to use fewer and fewer Chinese-sourced inputs over time. For clean electricity projects starting construction next year, 40% of the value of the materials used in the project must be free of ties to a FEOC. By 2030, the threshold would rise to 60%. Energy storage facilities are subject to a more aggressive timeline and would be required to prove that 55% of the project materials are non-FEOC in 2026, rising to 75% by 2030. Each covered advanced manufacturing technology gets its own specific FEOC benchmarks.

Unlike the text from the Finance Committee, however, the final text includes a clear exception for developers who already have procurement contracts in place prior to the bill’s enactment. If a solar developer has already signed a contract to get its cells from a Chinese company, for example, it could exempt that cost from the calculation. That would make it easier for companies further along in the development process to comply with the eligibility rules.

That said, these materials sourcing rules come on top of strict ownership and licensing rules likely to block more than 100 existing and planned solar and battery factories with partial Chinese ownership or licensing deals with Chinese firms from receiving the tax credits, per a BloombergNEF analysis I reported on previously.

Once again, the details of how any of this will work — and whether it will, in fact, be “workable” — will depend heavily on guidance written by the Treasury department. That not only gives the Trump administration significant discretion over the rules, it also assumes that the Treasury department, which is now severely understaffed after Trump’s efficiency department cleaned house earlier this year, will actually have the bandwidth to write them. Without Treasury guidance, developers may not have the cost certainty they need to continue moving forward on projects.

Solar leasing is back in

Up until today, the Senate and House looked poised to destroy the business model for companies like Sunrun that lease rooftop solar installations to homeowners and businesses by cutting them off from the investment tax credit, which can bring down the cost of a solar array by as much as 70%. The final Senate bill, however, got rid of this provision and replaced it with a much more narrow version.

Now, the only “leasing” schemes that are barred from claiming tax credits are those for solar water heaters and small wind installations. Companies that lease solar panels, batteries, fuel cells, and geothermal heating equipment are still eligible. SunRun’s stock jumped nearly 10% on Tuesday.

A bizarre new coal handout

Other than the new FEOC rules, which will have truly existential consequences for a great many projects, there aren’t many changes to the advanced manufacturing tax credit, or 45X, than in previous versions of the bill. The OBBBA would create a new phase-out schedule for critical mineral producers claiming the tax credit that begins in 2031. Previously, critical minerals were set to be eligible indefinitely. It would also terminate the credit for wind energy components early, in 2028.

One significant change from the Senate Finance text is that the bill would allow vertically integrated companies to stack the tax credit for multiple components.

But perhaps the biggest change, which was introduced last weekend, is a twisted new definition of “critical mineral” that allows metallurgical coal — the type of coal used in steelmaking — to qualify for the tax credit. As my colleague Matthew Zeitlin wrote, most of the metallurgical coal the U.S. produces is exported, meaning this subsidy will mostly help other countries produce cheaper steel.

Hydrogen gets a reprieve

It looks like the hydrogen industry’s intense lobbying efforts finally paid off: The final Senate bill is the first text we’ve seen since this process began in May that would extend the lifespan of the tax credit for clean hydrogen production. Now, projects that begin construction before January 1, 2028 will still qualify for the credit. This is shorter than the Inflation Reduction Act’s 2033 cut-off, but much longer than the end-of-year cliff earlier versions of the bill would have imposed.

EVs and energy efficiency are still out

The tax credits for electric vehicles and energy efficiency building improvements would end almost immediately. Consumers will have to purchase or lease a new or used EV before September 30, 2025, in order to benefit. There would be a slightly longer lead time to get an EV charger installed, but that credit (30C) would expire on June 30, 2026.

Meanwhile, energy efficiency upgrades such as installing a heat pump or better-insulated windows and doors would have to be completed by the end of this year in order to qualify. Same goes for self-financed rooftop solar. The tax credit for newly built energy efficiency homes would expire on June 30, 2026.

Enhanced oil recovery and corn ethanol still win

The bill would make similar changes to the carbon sequestration (45Q) and clean fuels (45Z) tax credits as previous versions, boosting the credit amount for carbon capture projects that do enhanced oil recovery, and extending the clean fuels credit to corn ethanol producers.

What’s next?

The House Rules Committee met on Tuesday afternoon shortly after the Senate vote to deliberate on whether to send it to the House floor, and is still debating as of press time. As of this writing, Rules members Ralph Norman and Chip Roy have said they’ll vote against it.