Through the RE-Powering America’s Lands Initiative, the U.S. Environmental Protection Agency (EPA) promotes the reuse of potentially contaminated properties, landfills, and mining sites for renewable energy generation.  The EPA notes the following benefits for siting solar photovoltaic (PV) facilities on potentially contaminated lands and municipal solid waste landfills:
- May provide an economically viable reuse for sites that may have significant cleanup costs or low real estate development demand;
- May have environmental conditions that are not well suited for commercial or residential redevelopment;
- Can be developed in place of limited open space, preserving the land as a carbon sink and/or for other ecosystem services;
- Are generally located near existing roads and energy transmission or distribution infrastructure;
- Are typically located near areas with high energy demand (e.g., large population bases);
- Are constructed with large areas of minimal grade (0-2 percent);
- Are offered at lower land costs when compared to open space;
- Can accommodate net metered or utility scale projects;
- May be adequately zoned for renewable energy;
- Can provide job opportunities in urban and rural communities;
- Can advance cleaner and more cost-effective energy technologies; and
- May reduce the environmental impacts of energy systems (e.g., reduce greenhouse gas emissions).
Closed or capped landfills have very few complementary uses, and brownfields, which by definition may be complicated by the presence or potential presence of a hazardous substance, pollutant or contaminant can require millions of dollars in remediation costs before they can be safely reoccupied. However, Silvio Marcacci, Communications Director at Energy Innovation, suggests both types of locations offer advantages for siting solar projects.
Marcacci notes that landfills are typically elevated high above surrounding trees and buildings, offering unshaded sites capable of boosting potential solar output throughout the day, and are often already connected to the grid through methane generation operations. Brownfields, on the other hand, are typically located at former industrial sites that have been cleared of above-ground structures, providing flat unshaded expanses, often in proximity to existing power lines or large potential industrial customers like warehouses or factories. In both instances, projects can capitalize on higher generation potential and existing grid infrastructure.
Landfills and brownfields are also typically located within or close to major cities. According to Marcacci this is important because it means they can add new clean electricity generation in population centers without adding pollution and can tap the rising popularity of community solar projects. Since these locations are often considered environmental concerns, he suggests nearby residents will likely consider renewable energy a positive way to use the land, reducing public concerns compared to solar development in forested or undeveloped open spaces.
Utilities and solar developers can also benefit from favorable project economics through specific incentives from federal and state governments eager to return landfills and brownfields to productive use. At the federal level, EPA’s Brownfields Program provides grants and technical assistance to sustainably reuse contaminated property, and multiple state and local governments provide similar incentives.
In 1988 there were an estimated 7,924 landfills in the U.S. By 2009, however, that number dropped to 1,908.
According to the EPA, the landfills that closed over the intervening years—plus portions of active landfills with closed cells—represent hundreds of thousands of acres that may be suitable for siting solar PV facilities.
That’s important because these sites could help meet goals for solar generation without causing new environmental concerns. For instance, design innovations like ballasted racking systems mean panels can be secured atop landfill caps or remediated ground without disturbing hazardous materials beneath the array. Others design innovations include geosynthetic caps, which eliminate erosion issues typically associated with conventional panels due to rain and the need to mow around them.
Equally important, according to Marcacci, local governments and property owners win by returning unusable land to productive use while generating new income and property tax revenue. Utility companies win by building profitable solar generation close to areas of high electricity demand while avoiding siting conflicts and ecological concerns. Residents win through reduced local power plant emissions and expanded access to local high-tech jobs.
The EPA is actively tracking more than 170 renewable energy projects that are in various stages of planning, approval, or construction on contaminated or disturbed properties, including landfills. Representative examples include:
- Rochester, New York – 7,800 solar panels installed atop the 7-acre Emerson Street Landfill, capable of generating up to 2.6 megawatts (MW) of electricity.
- Randolph, Plainville and East Bridgewater, Massachusetts – 41,000 solar panels across three closed landfills capable of generating 13.5 MW. (Massachusetts now has about 70 such projects; these compromise more than half of solar landfill projects in the U.S.)
- Annapolis, Maryland – Construction underway for a 16.8 MW solar array over an 80-acre landfill. (The park will have 54,000 solar panels and is expected to create new jobs, support local businesses, offer learning opportunities for local students, and generate more than $5 million for the city over the course of its 20-year lease.)
Finding Suitable Opportunities
Using screening criteria developed in collaboration with the National Renewable Energy Laboratory (NREL), EPA has also pre-screened more than 80,000 brownfields and municipal solid waste landfills covering 15 million acres across the country for suitability as renewable energy generation facilities, including utility-scale solar. The EPA completed the screening in August 2018 and maps depicting the locations of these EPA tracked sites and their potential for supporting renewable energy generation can be found at https://www.epa.gov/re-powering.
- The maps enable users to view screening results for various renewable energy technologies at each site.
- The corresponding database can be searched by a number of attributes including state, acreage, renewable energy capacity, distance to nearest urban center, and more.
- Site–specific screening reports are available for each property.