The analysis, overseen by professors at Princeton and Dartmouth experienced in modeling climate policy’s effects, finds that the incentive aimed at U.S. manufacturers makes domestic solar panels more than 30 percent less costly to produce than imports. With incentives claimed by clean energy developers that meet labor standards and use domestic content, the total cost of generating utility-scale solar electricity could be lowered by 68 percent, and onshore wind energy by 77 percent.

The study was funded by the BlueGreen Alliance, a partnership of unions and environmental groups. The organization has championed elements of the Biden administration’s climate agenda that support domestic manufacturing, particularly in places hurt by globalization, automation and the decline of fossil fuels.

“Until now, the moral case and the business case did not always align,” said Ben Beachy, the organization’s vice president for industrial policy. “The I.R.A. changes that by offering developers an airtight business case for supporting high-paying jobs and a stronger and fairer U.S. manufacturing base.”

The impact of the climate law is already evident, with announcements of 47 new plants to make batteries, solar panels and wind turbines since it was passed, according to American Clean Power, a trade association. Other analyses, including a paper by economists and engineers at the Electric Power Research Institute, the Federal Reserve Bank of Minneapolis and the University of California, Berkeley, found that the law would encourage more low-emissions projects eligible for uncapped tax credits than anticipated, potentially making the costs to the government substantially higher than earlier estimates.