President Donald Trump’s new ​“big, beautiful” law repeals many — but not all — of the U.S.‘s clean-energy tax credits. The incentives that remain, though, could still prove prohibitively complex, rendering them effectively useless for energy project developers and manufacturers.

That’s because of a provision in the bill aimed at restricting Chinese companies and individuals from benefiting from those tax credits. These restrictions on ​“foreign entities of concern” — ​“FEOC” for short — combine harsh penalties with very little guidance on compliance. The impact of rules meant to limit U.S. funds flowing to China could, ironically, be to undermine U.S. efforts to compete with China, which dominates many of the industries that will bear the brunt of the requirements, experts say.

The ramifications of FEOC rules will be felt most by developers of grid-scale battery, geothermal, and nuclear energy projects as well as by companies that produce batteries, solar panels, and critical minerals in the United States. The law preserved tax credits for these sectors until the 2030s, subject to FEOC provisions.

The FEOC provisions in the bill passed last week aren’t as strict as those that emerged from a House version of the bill in May, experts say. But they’re still complex enough that experts fear it will take the U.S. Treasury Department a long time to finalize its rules for compliance. The bill sets a deadline for the department to issue its FEOC rules by the end of 2026.

That puts the industry in a bind. Until the guidance is finished, it will be risky for companies to claim tax credits — and riskier yet for the investors who finance clean-energy projects and factories by purchasing these credits to offset their own tax bills. These entities would face the risk of eventually having their tax credits clawed back if they’re later found to be in violation of the as-yet-unwritten rules, Lee said, among other penalties.

“When I talk to developers, manufacturers, lawyers, and tax insurers and other participants in this market, they’re not sure how they’re going to deal with this,” Lee said. ​“There’s a risk that some projects get so burdened in compliance and red tape that projects and investments that should move forward will not be able to.”

To make matters more challenging, the IRS has a long time to challenge tax credit claims, said Andy Moon, CEO and cofounder of Reunion Infrastructure, a company that offers software and services to support the multibillion-dollar market for tax-credit transfers. The department has six years after a return is filed, and can assess a 20% penalty for incorrect claims — in addition to clawing back the value of the credit.

The confusion ultimately threatens to put hundreds of billions of dollars worth of planned investment in clean-energy projects and factories on ice while companies wait for the details to take shape. It could also sow chaos for the hundreds of billions of dollars worth of existing projects that have been built with the assumption that they could access Inflation Reduction Act tax incentives.

It’s unclear whether every company will be able to find alternative suppliers that comply with the FEOC rules. China makes most of the world’s solar and lithium-ion battery materials and components, including those used in domestic installations and factories. For some projects, that might be OK. Certain energy developments and factories will still make economic sense without tax credits. But plenty won’t.

“The industry has not yet fully absorbed the potential impact of FEOC rules, which will kick in starting in 2026,” said Moon. ​“And I think that some market participants are looking at it and raising the alarm bells.”

Crushed by complexity 

In particular, the ​“material assistance” rules that go into effect next year will prove a challenge for firms, Moon said. Under those rules, factories and energy projects seeking to claim tax credits must have an increasing proportion of materials coming from companies and sources that aren’t linked to FEOC.

For manufacturers seeking credits under the Inflation Reduction Act’s 45X program, those proportions will rise from 60% in 2026 to 85% in 2030 for lithium-ion batteries, while the proportions for solar manufacturers will rise from 50% to 85% over the same time period, for example. Manufacturers of other products have their own ratios, as do wind, solar, battery, geothermal, and nuclear power projects.

It won’t be easy for companies to prove they’ve met those thresholds, Lee said. ​“To do that, you have to go through a calculation that’s described at a high level in the text” of the bill, he said. ​“But the details of how you do that calculation are somewhat unclear,” with only passing reference to existing domestic-content ​“safe harbor” guidance for solar, wind, and battery projects.

Yogin Kothari, chief strategy officer for Solar Energy Manufacturers for America, a coalition of U.S. solar-equipment makers, said that the companies in his organization are working with the Trump administration and members of Congress to forward ​“a set of rules that supports domestic manufacturers and drives demand for domestic manufacturing. Anything that undermines that will have a negative impact on these manufacturing communities.”

“NEMA is going to work with Treasury as best as possible to ensure that the guidance is clear and consistent and produced in a timely enough manner for companies to use the credit for those that wish to take advantage of it,” he said. Even so, ​“there’s going to be a decision for a number of companies and organizations as to whether or not the juice is worth the squeeze.”