A solar solution

In Mount Olive Township, New Jersey, township officials considered various reuse options for a long-closed landfill site, from turning the property into a golf course to building a strip mall. Township officials quickly learned that, because of concerns over breaking the landfill’s protective seal, redevelopment potential for closed and capped landfills is low. At one point, the township even considered foreclosing on the property, which, like many closed landfills, had become a tax drain.

After a series of dead ends, Andrew Tatarenko, business administrator for the township of Mount Olive, says the county landed on a plan to develop the Combe Fill North Landfill site into a solar installation generating clean, renewable, carbon-free power. It’s a reuse option that can work on many closed landfill sites.

“Solar energy is a great way to transform the site and to provide green energy, jobs and produce revenue,” Tatarenko says.

The Combe Fill North Landfill, occupying about 65 acres of a 100-acre property, served as a municipal sanitary landfill in the 1960s and ’70s before being abandoned. However, the landfill was never properly closed and in 1982 was named a U.S. Environmental Protection Agency (EPA) Superfund site because of runoff draining into groundwater and subsequently capped and monitored. In 2019, township officials embarked on a redevelopment study to determine whether it qualified as an area in need of development.

“This opened the doors for the township to pursue other options,” Tatarenko says.

After many years of stops and starts with previous developers, the township auctioned off the tax sale certificate to CEP Renewables, a Red Bank, New Jersey-based solar development company. CEP and the township entered into a public-private partnership, with CEP taking ownership of the property after it went through an innovative tax sale foreclosure/redevelopment deal structure and developing one of the largest landfill solar projects in the eastern United States.

The 25.6-megawatt solar project, called Mount Olive Solar Field, provides clean power for more than 4,000 homes and generates tax revenue of about $50,000 a year, according to CEP. Revenue from the solar project allowed the township to pay back taxes of more than $2.2 million, Tatarenko says.

“Most importantly, CEP transformed what was once a serious environmental liability for the township into a green- energy and revenue-producing asset,” Tatarenko says.

Landfill-to-solar prospects

After a landfill closes, a list of postclosure caretaking responsibilities remains for property owners, including maintaining and repairing the cap, leachate removal and maintaining and monitoring leak detection and groundwater monitoring detection systems.

Deferring those postclosure care responsibilities is one of the biggest selling points to solar installation, says Kurt Princic, senior project development manager for CEP Renewables, which develops, designs and builds community-scale solar plants.

Princic, whose background is working with the Ohio EPA’s solid waste program, reaches out to property owners across the country, with a focus on landfills and brownfield sites in economically distressed areas, to see if they are interested in exploring solar installations.

“We … feel like it’s [a] win-win for everyone. For communities, they typically have properties that are underutilized and are really not paying any significant amount in tax revenues,” Princic says. “Regulators like it because we enter into long-term contracts—typically, the developers will handle all the cap maintenance, extending postclosure care for decades.”

CEP has solar projects in production at more than 15 landfills. Typically, the company takes the lead in working with regulatory agencies to secure any necessary local, county, state and federal permits and incurs all costs for development, permitting and installing the solar project. Once the project is operational, CEP oversees operations as well as addressing cap, road and fence maintenance for the site.

“We are responsible for everything aboveground,” Princic says.

For solar energy, CEP typically enters into a net metering agreement with a local energy company to put renewable electricity into the grid through community solar programs.

Owners also benefit from revenue generation. Solar projects can generate $9,000 per megawatt per year in revenue for owners to help pay for postclosure costs, and they have a life cycle of 20 to 30 years. While CEP entered into a purchase agreement for the Mt. Olive site, for most landfills, the company enters into long-term lease agreements of about 20 years.

Additionally, the local community receives property taxes at $9,000 per year, paid by CEP Renewables.

“Communities are generally receptive. Rather than taking prime farmland [for solar installations], these sites are tax burdens to the community,” Princic says. “[Solar plants] can increase tax value to a community that otherwise wouldn’t have that opportunity. The majority welcome solar on these properties with open arms.”

Design and layout

Before installing a solar array at the Mount Olive site, CEP Renewables worked with Edison, New Jersey-based CS Energy to complete a landfill settlement analysis to determine landfill weight requirements and the safest access points.

When setting up a solar project in a landfill area, CEP uses a ballasted design for panels and electrical wires, with no landfill cap penetration.

Based on that analysis, CEP used tracked equipment and low-ground-pressure machinery to install to install the solar arrays with no penetration into the landfill cap. Panels were situated with 15-to-20-foot spacing between rows with electrical wires located below ground when possible. In terms of topography, CEP can install solar panels on a slope of up to about 15 percent.

When it comes to maintenance, Princic says solar projects are “pretty set-and-forget for the most part.”

“There are no moving parts like a traditional power plant,” he explains.

Each year, CEP staff take two to four truck crawls at each site, mowing grass with a Weedwacker and monitoring equipment and lines. Cap maintenance on landfills generally entails keeping the grass mowed and preventing any woody vegetation from taking root, Princic says.

Additionally, the company maintains close relationships with the state Departments of Environmental Protection, Princic says, adding, “We want to make sure anything we do is not going to impact the cap system or engineering.”

How does it end?

What happens when the solar plant’s 30-year life cycle is up? CEP hasn’t reached that milestone with any of its projects yet, but it plans to work with organizations to recycle the solar panel equipment and, if necessary, return the land to its original state. Across the U.S., according to CEP, there are more than 10,000 closed landfills, and those properties could host more than 60 gigawatts of solar capacity—enough to power 7.8 million homes.

Tatarenko says, “This model on how landfill solar projects can scale and transform contaminated properties to productive lands that deliver sustainable, clean energy and improve the quality of life for those living nearby can be duplicated by other municipalities.”

The author is managing editor of Waste Today and can be reached at smann@gie.net.