From Trash to Power
Woodstock Landfill Set to Become Baltimore County’s Biggest Solar Project
On a chilly Monday night, in the basement of a small, old stone church, a handful of local residents gathered to hear about the future of a long-closed Baltimore County dump: the former Hernwood Landfill located in Woodstock, Maryland.
Seth Blumen, Baltimore County’s Energy and Sustainability Coordinator, shared plans to transform it into one of the county’s largest solar energy projects.
The Hernwood Landfill closed in 1982. In 1988, Baltimore County agreed to install a cap to prevent rainwater and runoff from entering the site; however, the cap was reportedly never implemented. The Maryland Department of the Environment later sought a $50,000 penalty against the county for repeated environmental violations.
Blumen explained that the landfill was ultimately capped in December 2007, but the land remains unusable for housing, commercial development, or agriculture.
“Old dumps are actually ideal for solar,” Blumen noted. “You can’t build on the land or farm it; it has very limited uses.”
The landfill spans roughly 295 acres, though solar panels will only be installed on the “cell tops”—large meadow areas that sit above compacted waste layers. Beneath those meadows is a geosynthetic cap designed to protect the waste below, a feature that heavily influences how the solar array can be built.
To avoid disturbing the cap, the panels will be mounted on concrete ballasted blocks rather than driven into the ground. Construction cannot go deeper than 12 inches, and strict limits are placed on ground pressure and weight.
Steep slope areas and the edges of the landfill cap will be avoided entirely, with a required 10-foot buffer zone. All drainage and construction plans must be approved by the Maryland Department of the Environment, and Blumen said environmental studies for the project have already been completed.
The Hernwood Landfill Solar Project is expected to be a 13-megawatt system capable of generating approximately 18 million kilowatt hours of electricity per year. By comparison, the Parkton Landfill solar project is a 6.7-megawatt system that produces about 8.2 million kilowatt hours annually.
Together, the two projects are expected to help Baltimore County reach 55 percent renewable energy usage once Hernwood is fully operational.
The project is being developed through a power purchase agreement with TotalEnergies, formerly SunPower, which owns, operates, and maintains the system. TotalEnergies leases a portion of the county-owned site, while Baltimore County purchases the electricity generated.
“We’re saving a lot of money in terms of electricity by using BGE Aggregate Net-Metering,” Blumen said. “We’re crediting numerous county accounts. We get the renewable energy credits, reduce costs for other facilities, and guard against rising electricity prices. It’s a win-win.”
The county will pay a fixed Power Purchase Agreement (PPA) rate to the solar developer, intended to lock in electricity costs below the rate it would otherwise pay. The electricity will be applied to county facilities such as police and fire stations, libraries, senior centers, and recreation centers.
Construction is expected to begin in November of this year, pending coordination with BGE. The system will be interconnected through an adjacent private property, requiring both overhead and underground electrical infrastructure. If all goes as planned, the project is expected to be completed by October 2027.
The initial agreement runs for 25 years, with options to renew for up to five additional years. Like most solar installations, the system is expected to degrade slightly over time.
Residents also raised questions about wildlife and public access. Blumen said fencing will be limited to small areas needed for equipment security on the cell tops. The broader site, including the perimeter and main entrance, will remain accessible.
“We don’t want to change the character of the site too much,” he said. “People should still be able to enjoy it.”
As Baltimore County continues to look for ways to expand renewable energy while controlling costs, Blumen emphasized that projects like Hernwood are about both environmental responsibility and fiscal stewardship.
“As a county, we’re saving taxpayer dollars,” he said.
Edited on February 13 to remove the reference to the Baltimore Sun report regarding a 14-cent per kilowatt-hour rate, pending clarification. Added that the county will pay a fixed Power Purchase Agreement (PPA) rate.
References:
“Long-shuttered Parkton landfill to get new life as solar project.” The Baltimore Sun, 10 October 2025.
“Baltimore County to correct environmental violations” The Baltimore Sun, 14 January 2005.
“State seeks action on landfill violations; Penalties threatened over Hernwood, Eastern sites; county denies changes.” The Baltimore Sun, 30 July 2004.
Joy, do you have a map of the site? I’m not exactly sure where the old landfill is located.