Today, Evergreen Collaborative and Sierra Club released a groundbreaking new report detailing how policymakers and state agency regulators can slash harmful air pollution from U.S. manufacturing facilities while driving industrial modernization. The report highlights a major and often overlooked opportunity to electrify one of the largest and most widely distributed sources of air pollution in the country: industrial boilers. As the Trump administration continues to dismantle federal climate and clean air protections, this report provides state and local leaders with a timely, practical roadmap to clean up one of the dirtiest corners of U.S. manufacturing and help ensure sustainable, competitive industrial growth.

The report, “Embracing Clean Heat: Opportunities for Zero-Emission Industrial Boilers,” provides a detailed overview of the industrial boiler landscape, currently dominated by fuel-combusting units. It introduces a first-of-its-kind national dataset that maps nearly 14,000 combustion boilers across all 50 states and Puerto Rico, offering vital insights into the scale and geographic distribution of pollution emitted by these units.

Examples of key findings: 

• Boilers are a major source of harmful pollution: Alongside their massive emissions of greenhouse gases, combustion boilers release enormous amounts of conventional pollutants that can impair lung and cardiovascular health, cause cancer, and lead to premature death. For instance, industrial boilers emit more smog-forming nitrogen oxides (NOx) than major industrial sectors like coal-fired power plants, oil refineries, and cement plants.

• Boiler pollution disproportionately impacts vulnerable communities: 66 percent of the highest-emitting boilers are located in federally designated disadvantaged communities, where average annual NOx emissions are nearly double the national average. Moreover, 25 percent of boilers are located in areas that already exceed legal air pollution limits.

• Boiler populations are heavily concentrated: Nearly 40 percent of boilers in the dataset are located in one of five states: California, Minnesota, Illinois, Massachusetts, and Texas.

Fortunately, clean alternatives for generating industrial heat—such as heat pumps, conventional electric boilers, and thermal energy storage—are already commercially available. These technologies can deliver industrial heat without on-site emissions and can dramatically reduceboth greenhouse gas and conventional pollutant emissions, even when accounting for upstream electricity generation.

Despite the significantly higher efficiency—especially in the case of heat pumps, which can reach efficiencies of up to 400 percent—clean alternatives to combustion boilers  have yet to gain widespread adoption in the industrial sector. This slow uptake underscores the crucial role that policymakers, particularly at the state and local level, must play in facilitating the transition to zero-emission industrial heat. The report provides an in-depth analysis of the economic landscape surrounding boiler electrification and presents a comprehensive roadmap spanning economic, legal, and policy strategies to accelerate the deployment of clean thermal technology across U.S. manufacturing.  

Examples of policy recommendations:

• State-level clean air standards: States can leverage their existing legal authority to set stricter emissions standards on industrial boilers, going beyond outdated or absent federal regulations. By targeting pollutants like NOx and CO2 pollution at the source, states can protect public health and advance climate goals simultaneously.

• Strategic investment in electrification: States can close the cost gap between fossil-fueled and electric boilers through targeted measures such as production tax credits, workforce development programs, and clean heat incentives. These investments will not only accelerate decarbonization, but also create high-quality jobs, especially in disadvantaged and  frontline communities.

• Utility rate reform: Public utility commissions can modernize industrial rate structures to reward electrification and on-site energy storage, reflecting their benefits for grid flexibility and long-term savings. 

In addition to the main report, Evergreen Action and Sierra Club have also provided appendices that include references for further study, real-world case studies of covered technologies, and a comprehensive methodology of the dataset development process, as well as an executive summary of the report.

“Industrial boilers represent a huge opportunity,” said Trevor Dolan, Evergreen Action industry and workforce senior policy lead. “By stepping in with supportive policies, states can correct market failures, drive meaningful emissions reductions, and help manufacturers modernize for a more competitive, low-carbon future—while protecting the communities that have long borne the brunt of industrial pollution. This is the moment for states to lead and finally take on one of the dirtiest, most overlooked sources of industrial pollution.”

“A strengthened manufacturing base in the United States can help revitalize communities in our country that have been left behind for too long,” said Andres Restrepo, Sierra Club attorney.“However, its promise will be lost if manufacturers remain dependent on the fossil fuels that drive climate change and that pollute our air and water. As our report shows, by embracing clean technologies like heat pumps, policymakers can take a huge step cleaning up industry and paving the way for a healthier, more prosperous future for all.”

“Switching from dirty, outdated boilers to clean, modern heat systems is one of the smartest ways to cut pollution and save money in the long run,” said Justine Hackimer, Ohio River Valley Institute (ORVI) industrial decarbonization program manager. “This report shows that boiler pollution is a serious problem in Pennsylvania—but the good news is, we have real solutions. With nearly $400 million available through the state’s RISE PA program, local manufacturers have a great opportunity to lead the way in building a cleaner, healthier future for our communities.”

"For too long, communities like ours in the Inland Valley have lived in the shadow of polluting industries—with higher rates of asthma, cancer, and respiratory illness to show for it," said Ana Gonzalez, Director of the Center for Community Action and Environmental Justice in the Inland Valley. "This report makes clear what we already know: environmental justice communities are on the frontlines of industrial pollution. We need bold action to clean up these emissions and ensure a healthier future for all Californians.”

Read the full report here. 

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