Fairfax County, Virginia, is converting 37 acres of the I-95 Landfill, in Lorton into the county’s largest solar array.
“The ground we’re standing on now is the closed landfill part of our site — it closed in 1990,” said Eric Forbes, deputy director of the county’s Department of Public Works and Environmental Services, during a WTOP tour of the landfill. “We’re actually standing on trash,” covered by layers of a landfill cap and grassy vegetation, to prevent water from entering.
When it’s completed, energy produced from the solar array will be used to power county government buildings, with the goal of saving the county $12 million over a 30-year partnership and reducing carbon dioxide emissions by 136,000 metric tons over the same period.
Unlike many other landfills, where the county’s garbage is deposited onto a landfill and eventually covered with dirt, Fairfax County has been operating the Lorton site as a waste-to-energy facility since 1990.
“Reworld is a waste-energy or energy from waste facility, where they take garbage from our households and businesses and then it’s converted into electricity,” Forbes said about the privately owned company that operates the mass burning facility at the landfill.
“It’s incinerated or burned through a furnace system that boils water to create steam, that generates the energy to turn turbines, essentially creating electricity that goes back to the grid for powering homes and businesses in our community,” Forbes said.
Ash from the Reworld plant is added in the open portion of the landfill.
The now-closed portion of the landfill isn’t suitable for typical redevelopment, Forbes said, pointing to the expansive mountains of the grassy landfill.
“There’s a 5 megawatt solar array of about 1,200 solar panels that will be installed over our slope here.”
The panels are secured with an aboveground bracket system, weighed down with rocks. Several panels have been installed in the week since official groundbreaking for the project.
Typically, with rooftop installations of solar panels, power goes directly to the home or building below the panels.
“This facility, a utility scale project, we have virtual net metering, where the energy produced here will go through the Dominion system and be credited back to our accounts throughout the community,” Forbes said. “So, a government building in Great Falls or Centreville could actually be using the electrons that are generated here in Lorton.”
The county is leasing a portion of the landfill to Madison Energy Infrastructure, a clean energy company that will design, permit, build, own, operate and maintain the project. The county pays Madison for the energy produced over the term of a 30-year agreement.
“We have a 30-year agreement with them, and we actually pay them a fixed rate over that time,” Forbes said. “So, as energy prices increase over time, our rate will stay the same, and that green energy will continue to be provided for our county facilities.”
Forbes said installation of the solar project will continue through approximately March 2026, with the goal of being fully operational next spring.
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