A halt to clean energy tax credits being considered in the Republican-controlled Congress and by the Trump administration could boost electricity prices in Maine by 17% over the next 15 years, adding an average of $15 to a monthly bill, according to a study by an Austin, Texas, research organization.

Nationwide, eliminating incentives from the Inflation Reduction Act for wind, solar and storage systems could result in a $336 billion drop in investment and 237 gigawatts less clean energy generation capacity by 2040, according to the report by Aurora Energy Research. The capacity lost is equivalent to what’s needed to power about 35.7 million homes for one year.

“With Congress working on the new budget it seemed important to us to inform policymakers on potential impacts of making changes to those clean energy tax credits,” Olivier Beaufils, head of USA Central at Aurora, said Tuesday in a web-based presentation.

Lizzie Bonahoom, a researcher on the report, said it’s “not exactly clear” that cutting clean energy tax credits will eventually be approved by Congress; the subsidies are not universally opposed by Republicans who form narrow majorities in the House and Senate, and are broadly embraced by Democrats who supported the Inflation Reduction Act initially proposed by President Joe Biden and enacted in 2022.

Different versions of a budget are being drafted in the House and Senate, with disagreements on key elements of a plan that includes energy, immigration and defense policies.

The authors of the study said its results are likely to be a conservative estimate of the impact on investment, jobs and clean tech deployment because it limited its focus to wind, solar and storage tax credits. Other clean energy policies, such as support for electric vehicles, hydrogen, local energy projects and the potential impact on sectors such as manufacturing, were not part of the project’s scope.

Eliminating tax credits could lead to a $22 billion-a-year falloff in clean power investment in the U.S.; in Maine, the loss would be $100 million annually, according to the report.

Nearly 1,500 megawatts of power generated by onshore wind, battery storage and solar energy would be lost in the next 15 years in Maine, with most disappearing by 2030. The result would be a loss of less expensive clean energy produced in Maine, exposing consumers to price volatility for fossil fuels such as natural gas and oil, whose prices are tied to global markets.

Dropping federal incentives for clean energy would add an average of $5 a month to Mainers’ electricity bills by 2030 and $15 a month by 2040, Aurora Energy Research said.

Electricity prices in Maine and in New England are already high compared with other states due to the price of natural gas, which is a significant resource used by generators; gas pipeline constraints, such as limited capacity; and clean energy policies.

The price of electricity in Maine was 26.3 cents a kilowatt-hour in November 2024, according to the U.S. Energy Information Administration. It was even higher in Connecticut, at 29.15 cents a kWh and 30.28 cents for Massachusetts ratepayers. In contrast, the price of electricity in Illinois was 17.2 cents a kWh, 18.1 cents in Delaware and less than 13 cents in Missouri, according to the agency.

The authors of the report say it’s “fully independent,” does not favor any particular technology and does “not advocate for any specific policy or regulation.” Still, advocates and others are mobilizing to oppose efforts by Republicans in Congress and the Trump administration that favor drilling oil and natural gas and mining coal while opposing efforts to expand offshore wind and other zero-carbon resources.

The solar energy industry earlier this month lobbied Congress to maintain solar and storage energy and manufacturing credits in tax packages being considered.

And the Natural Resources Council of Maine released a report earlier this month saying that Maine businesses and residents and Wabanaki Nations benefited from $2.2 billion in federal clean energy spending and private investment incentivized by Washington.

The extent to which Biden administration initiatives such as the Inflation Reduction Act and Bipartisan Infrastructure Law that provides hundreds of billions of dollars in loans, loan guarantees, tax credits and other incentives are in jeopardy is not clear; funding that has already been provided  through contractual agreements is unlikely to be clawed back, though other funding could be halted.