How States Can Turn Polluted Lands Into Clean Energy

Electricity demand is booming in the United States. As the country electrifies its economy and builds out more data centers, electricity demand is projected to increase 25 percent by 2030.¹ In order to combat already rising electricity costs² across the nation, the United States must rapidly deploy all the lowest-cost energy it can at a massive scale. Sources of clean energy,³ particularly solar, are not only cheaper on average⁴ than fossil fuels but also faster to bring online.⁵ Nonetheless, new clean energy projects face challenges and delayed construction timelines.⁶ In particular, land use and siting can be a significant barrier. Renewables such as wind and solar have a large footprint, making them susceptible to community opposition and increasing risk of conflicts⁷ with other uses such as agriculture or wildlife habitat. These conflicts and opposition can lead to increased delays, litigation, and costs.

One potential solution is to repurpose abandoned, contaminated land such as closed landfills, abandoned mines, and brownfield sites, a broad term for lands whose redevelopment is complicated by contamination. These lands present a major opportunity⁸ to build clean energy with limited conflicts, while delivering benefits—including jobs, revenues, and contaminated site cleanup—to communities living nearby. A new Center for American Progress analysis of Environmental Protection Agency (EPA) RE-Powering America’s Land Initiative⁹ data finds that more than 81,097 previously contaminated sites across the United States could host utility- and distributed-scale (or “grid-scale”) wind and solar energy, totaling more than 940,000 megawatts (MW) in clean energy capacity. While not all sites will be suitable for clean energy,¹⁰ developing just 12 percent of this prescreened potential capacity by 2030 could offset growth in peak electricity demand.¹¹ The opportunity for build-out on contaminated lands will likely continue to grow as more than 850 coal and natural gas power plants¹² are set to close by 2030, though this may change in the face of rising electricity demand and changing federal policy.

Despite the promise of these sites, additional costs, informational barriers, and regulatory hurdles often deter developers and communities from pursuing projects on contaminated lands. These challenges are compounded by current federal attacks on funding and permits¹³ for renewable energy. Fortunately, several states have shown that strong policy can address many of these hurdles and unlock clean energy development on low-conflict, contaminated lands where other options for reuse are limited. This report highlights their successes and offers recommendations for others seeking to spur similar projects. Recommendations are provided for contaminated lands at large and for three specific site types: landfills, brownfields, and abandoned mines.

There are well-documented benefits¹⁴ to clean energy development on contaminated lands, sometimes referred to as “repurposed”¹⁵ energy or “brightfield”¹⁶ development. Sites typically require cleanup before use,¹⁷ transforming potential hazards into productive and safer community assets. Projects can help boost local employment and spending,¹⁸ push back against rising electricity prices,¹⁹ and generate revenue through leases and sales,²⁰ tax revenue, or other payments.²¹ Communities can also gain raised property values²² and potentially negotiate for additional benefits.²³

Contaminated lands can also be attractive from a developer’s point of view. For one thing, these sites are generally cheaper²⁴ to purchase or lease than productive greenfield sites, also referred to as undeveloped sites, though remediation costs may increase prices. Many contaminated lands are also in places with existing roads, electricity infrastructure, and fencing,²⁵ which could lower construction costs. Long wait times for grid interconnection approval²⁶ can slow projects down significantly; in 2023, the median wait time was five years.²⁷ Locating clean projects on contaminated sites such as retired coal or gas-fired power plants can provide access to preexisting interconnection rights.²⁸ Crucially, studies have shown strong community support²⁹ for clean energy projects on already-disturbed sites, helping mitigate community opposition.

Lastly, these projects deliver strong environmental benefits. In addition to the climate benefits that clean energy broadly brings, developing this infrastructure on contaminated lands eases pressure³⁰ to build on more sensitive, pristine lands that serve as important habitats, provide ecosystem services, or are valuable for agriculture.

Despite the benefits, developers and landowners face barriers to developing clean energy on contaminated lands. First are informational barriers: Since there is no comprehensive national inventory³¹ of abandoned mines and data can vary by state, it can be challenging for developers and communities to identify suitable sites or determine who owns them.³² Second, developers often have to pay extra for site cleanup and additional engineering challenges.³³ For example, to avoid penetrating a landfill cap, solar panels need to be ballasted³⁴ on top of the surface, creating additional costs. Damaged caps or preexisting structures can also complicate construction. Another issue is size. Larger installations can achieve economies of scale,³⁵ spreading out fixed costs such as manufacturing facilities and specialized installation equipment and resulting in lower per-unit costs. However, since many contaminated sites are small, it can be difficult for developers to achieve economical large-scale development. Contaminated sites also can come with complicated liabilities,³⁶ such as responsibility for cleaning up contamination at a site, from which developers often shy away. Lastly, projects on contaminated lands require additional state and federal environmental site assessments³⁷ and may have uncertain permitting timelines, adding to the potential costs and delays. Together, these factors mean that brownfield developments typically cost 10 percent to 15 percent more³⁸ than greenfield development.

In absence of guiding policies, developers will often target the path of least resistance:³⁹ developing on greenfields. Leaving contaminated lands idle is not only a potential health hazard but also a missed economic development opportunity that forfeits benefits for communities. Smart policy can help make these projects more attainable. The Inflation Reduction Act helped close the cost gap,⁴⁰ offering a 10 percent additional tax credit for clean developments on certain contaminated lands. However, now that the Big Beautiful Bill is prematurely phasing out⁴¹ the underlying clean energy tax credits for wind and solar, state policy will be more important than ever if the United States is going to meet electricity demand and keep electricity affordable.⁴²

While developers in almost every state have constructed clean energy on contaminated lands, Massachusetts, New Jersey, and New York have built on the most sites. These states offer a combination⁴³ of financial and nonfinancial incentives to developers, balancing redevelopment opportunities with state and local land use priorities.⁴⁴ Through 2024, only 581 solar, wind, or battery storage projects have been developed on contaminated lands, totaling approximately 4,300 MW in maximum capacity.

This is a small fraction of the more than 81,000 remaining prescreened sites, which could generate more than 940,000 MW—enough energy to power roughly 158 million homes during peak hours of the day⁴⁵—in viable utility- and distributed-scale wind and solar capacity, referred to as “screened potential capacity” from here forward in this report. Every state hosts contaminated sites with generation potential and should work to take advantage of these opportunities. The states with the largest amount of potentially developable capacity are Pennsylvania, California, West Virginia, Virginia, and New York. Each state has its own unique mix of site types, though overall, abandoned mines and brownfields have the largest potential for new clean energy capacity.

Based on CAP’s analysis of RE-Powering America’s Land data and review of the literature and state policies, this section provides examples of policies that states can pursue to accelerate clean energy development on contaminated lands. The first two examples significantly reduce development costs at little to no cost to states, while the third requires more investment from states to offset development costs. Finally, this section provides examples of how states can tailor these policies to facilitate development on certain types of contaminated lands.

1. Identify and communicate opportunity

States can help solve information barriers by evaluating the development opportunities within their borders, providing resources for communities and developers, and communicating support for redevelopment. For example, states can:

• Maintain public resources for developers and landowners. More data—including on-site ownership, reclamation status, and hosting capacity⁴⁶—allows for more robust prescreening. For example, New Jersey hosts a dedicated landfill solar website⁴⁷ as a “one-stop shop” for municipalities and developers, plus a community solar siting tool.⁴⁸
• Signal support for contaminated land redevelopment. Developers tend to look for reliable government and community partners. A renewable portfolio standard carveout or procurement preference⁴⁹ for projects developed on contaminated sites demonstrates policy support while stimulating demand for these projects.
• Provide technical assistance to communities. Local governments that host contaminated lands may not be aware of the opportunity⁵⁰ or have the expertise⁵¹ necessary to site these developments. Additional technical assistance as well as model local laws and guides⁵² could support them. States should prioritize projects that demonstrate community and local government support.⁵³
• Conduct feasibility studies. Pennsylvania,⁵⁴ Michigan,⁵⁵ Minnesota,⁵⁶ and Virginia⁵⁷ recently published state-specific assessments, identifying opportunities for development on landfills, brownfields, or abandoned mines in their states and issuing policy recommendations.

2. Enable shorter, more predictable development timelines

States should evaluate whether environmental review, permitting, and interconnection processes can be adjusted to ease development while balancing the public interest. This would provide developers and investors with greater certainty that their projects will be able to recover costs within a reasonable timeframe. For example, states can: 

• Allow easier pathways for complying with permitting and environmental review requirements. States can help by streamlining permitting for desired clean energy projects that have already demonstrated that they have limited conflicts. For example,⁵⁸ New York exempts certain brownfield and landfill projects from state environmental review and offers an alternate, expedited permitting process through its Office of Renewable Energy Siting⁵⁹ for projects of more than 25 MW. Explicitly limiting liability⁶⁰ for clean energy on state-administered contaminated lands could further ease⁶¹ developers’ concerns.
• Improve interagency coordination. Projects on contaminated lands often have complex processes crossing multiple jurisdictions. To the extent possible, states should coordinate agencies’ review of applications and administration⁶² of incentive programs. This will help developers better navigate complex processes and reduce agency bottlenecks. For example,⁶³ New Jersey’s Department of Environmental Protection coordinates all permitting and incentive processes in conjunction with the Board of Public Utilities and Economic Development Authority.

3. Offset costs where possible

States can also offer financial incentives to get more sites ready for development and more projects over the finish line faster. For example, states can:

• Supplement federal cleanup programs. Federally funded cleanup efforts⁶⁴ are generally delegated to the states, which can unlock more clean energy investment by targeting cleanup on sites with the most development potential. States can supplement funds such as the Abandoned Mine Lands (AML),⁶⁵ AML Economic Revitalization,⁶⁶ EPA Brownfield,⁶⁷ and Superfund⁶⁸ programs via state brownfield, Superfund, or voluntary cleanup programs.⁶⁹
• Offset development costs with financial incentives. States can also reimburse developers for preparing sites through brownfield redevelopment grant programs. For example, Rhode Island’s Renewable Energy Fund⁷⁰ offers grants to offset the costs of developing solar energy on certain contaminated sites. Incentives⁷¹ can also help offset costs; for example, brownfields and abandoned mine developments are among the only site types eligible for New Jersey’s⁷² Community Solar Energy program.
• Prepare sites for development. States can also directly undertake all preconstruction steps necessary, especially for sites that are particularly promising but difficult to prepare. New York’s Build Ready program⁷³ conducts all screening, site preparation, permitting, and interconnection processes on chosen contaminated sites, auctioning them off to developers in a “build-ready” state.

Understanding the challenges and opportunities of different land use types

States should be aware of the unique challenges of developing on different types of contaminated land and craft their policies accordingly.⁷⁴ This section provides nonexhaustive examples of how states can tailor the above recommendations to different land types. The following land types are not mutually exclusive but broadly align with the EPA’s RE-Powering classifications.⁷⁵

To date, landfills dominate contaminated clean energy site developments. Despite being a small portion of potential developable capacity on contaminated sites—just 6 percent, according to CAP analysis—they make up 21 percent of already-developed capacity and almost half of all developed sites. This is partly because landfills are arguably the most straightforward contaminated sites to develop at scale, despite having unique engineering challenges.⁷⁶ They are ubiquitous, monitored, managed, and capped⁷⁷—meaning they are covered⁷⁸ to isolate and avoid the spread of contamination—at the end of their lifespans and generally have straightforward ownership by local governments. When capped, they provide adequate open space and few other redevelopment opportunities.⁷⁹ Virtually every state has a significant amount of screened, undeveloped landfill capacity and would benefit⁸⁰ from some sort of landfill development policy.

In Wisconsin and Connecticut, landfills make up the greatest share of potential capacity—at 58 percent and 55 percent, respectively, and Massachusetts has developed more solar capacity on landfills than any other state. This is thanks in part to the state’s concerted effort⁸¹ to shift clean energy development away from limited high-value land.

Despite making up one-third of screened potential wind and solar capacity nationwide, abandoned mines provided only 12 percent of capacity on repurposed lands as of 2024. There are several reasons why the United States may struggle to redevelop abandoned mines at scale, including high costs of reclamation. Under the Surface Mining Control and Reclamation Act,⁸² mines abandoned since 1977 must be reclaimed—restored to as close to pre-mine condition as possible—by the owner. However, there are many legacy mines that were abandoned before 1977 for which previous owners are not liable. While these mines are eligible for funding through the Abandoned Mine Land program, if the federal government has not provided adequate funds, projects may prove too costly for a clean energy developer to take on. Even determining who has rights to mine lands⁸³ tends to be more complicated than with other site types due to the likelihood of multiple owners. But if these obstacles are overcome, reclaimed mines can be promising due to their large size compared with other contaminated lands.

Three of the six abandoned mine projects that have come online since 2016 were in New York. The states with the greatest relative shares of screened potential capacity on abandoned mines—Pennsylvania, West Virginia, and Virginia—share a history of coal mining.⁸⁴ Of these states, Pennsylvania and West Virginia are together receiving⁸⁵ up to $219 million⁸⁶ in federal funding to pilot solar on mines under the Infrastructure Investment and Jobs Act’s Clean Energy Demonstration Program on Current and Former Mine Land.

In this report, “brownfields” is an umbrella term⁸⁷ for sites complicated by potential contamination or hazardous materials, as designated by the EPA or state environmental agencies. This can include mismanaged landfills and abandoned mines but also contaminated farmlands, warehouses, retired factories, and coal power plants. Brownfields make up 28 percent of potential screened capacity in the United States and 18 percent of capacity developed to date. On average, brownfield sites occupy a smaller footprint than contaminated lands overall and may still contain structures that require demolition or otherwise complicate development. Their redevelopment may also be subject to strict environmental regulation.⁸⁸ However, the designation of a site as a brownfield opens doors to subsidized remediation.⁸⁹ These sites may be advantageous as they are often near population centers⁹⁰ and other places with high electricity demand.

New Jersey stands out for its robust policy framework, which has helped deliver 36 projects on brownfields in the state. Oregon and Maine both owe more than 80 percent of their known potential capacity on contaminated lands to brownfields. This may be due to programs that flag and monitor these types of sites in these states.⁹¹

Site types with additional challenges: Superfund and Resource Conservation and Recovery Act sites

CAP’s analysis also found that there is significant additional opportunity on Superfund and Resource Conversation Recovery Act (RCRA) sites. Both are heavily contaminated, hazardous sites that pose significant challenges for redevelopment.⁹² Superfund sites are governed by the Comprehensive Environmental Response, Compensation, and Liability Act and are uncontrolled or abandoned, whereas RCRA sites are largely still in active use and have defined ownership. Superfund sites constitute about 21 percent of projects developed to date—45 percent of developed capacity—and about 15 percent of the United States’ estimated potential capacity. In particular, Montana, South Dakota, Idaho, and Washington have significant amounts of potential capacity on Superfund sites. According to CAP analysis, RCRA sites represent about 22 percent of screened potential capacity nationwide but just a small fraction (3 percent) of capacity developed to date—likely because they are still in active use.

The heavy contamination in these sites makes them particularly difficult and expensive to redevelop. However, there are some examples of successful redevelopment including a major solar installation at the Edwards Air Force Base⁹³ in California and a wind power project at Bethlehem Steel Wind⁹⁴ in New York. More research is needed to better understand how states can support these types of developments. States may benefit from prioritizing sites with significant clean energy development potential for Superfund cleanup funding.

Clean energy on contaminated lands presents a significant opportunity to revitalize communities while relieving the development pressure on more pristine lands. While such projects present additional challenges compared with greenfield development, leading states such as New Jersey, New York, and Massachusetts have demonstrated how strong policies can help enable building on these areas. State decision-makers should capitalize on this economic development opportunity with supportive policies that identify and communicate opportunity, enable predictable development timelines, and help lower costs. The effectiveness of these policies demonstrates repurposed lands’ promise to be productive and critical assets in the country’s future electric grid.

The authors would like to thank Jenny Rowland-Shea, Kendra Hughes, Lucero Marquez, Nicole Gentile, Anh Nguyen, Bill Rapp, Hannah Wiseman, Kate Petosa, Margaret Cooney, Bianca Serbin, Chester Hawkins, and Meghan Miller for their contributions.

Estimates of developed and screened potential capacity by state are derived from the EPA’s RE-Powering America’s Land initiative.¹⁰¹ The EPA offers acreage and prescreened potential capacity site data for undeveloped/underdeveloped sites, from which CAP derived screened potential capacity estimates. Sites that theoretically are developable but lack sufficient data for the EPA to estimate developable capacity were excluded. Unless otherwise specified, developable capacity estimates assume the highest-capacity choice between wind and solar for each site.

To analyze already-developed projects, CAP used the EPA’s Re-Powering Tracking Matrix.¹⁰² The authors included projects on landfill buffers in the “landfill” category and included “state brownfields” in the “brownfields” category.

CAP eliminated from screened potential capacity and site count totals any sites in the RE-Powering dataset that had been screened and were later reasonably fully developed or nearly fully developed. To determine which sites were developed, CAP projected 500-foot radii from all developed sites in EPA’s Re-Powering Tracking Matrix¹⁰³ and visually confirmed the presence of any solar or wind projects using Google Maps in EPA screened sites. Sites that appeared to be minimally developed were counted toward screened potential capacity and site count totals, as were sites that are developed for other RE-Power renewable energy categories, such as geothermal or biomass energy, as these can host additional wind, solar, and/or storage capacity.

CAP adhered to the EPA’s classification of projects as either “utility-scale” or “distributed-/community-scale,” except for one solar project that was deemed too far from the nearest transmission line to count as utility-scale and 478 distributed solar projects that are missing capacity estimates. An additional 167 projects that RE-Power had screened were deemed reasonably fully developed. Please refer to the EPA RE-Powering program for methodology.¹⁰⁴

Other factors can affect site technical feasibility, including but not limited to slope, the presence of sensitive habitat and impeding structures, and local grid constraints. Sites are nonexhaustive and represent only those that EPA screened in 2021; CAP’s analysis should be considered demonstrative. The total amount of developable capacity on sites across all land types exceeds the stated overall total because sites can fall into multiple categories.