A prominent company known for its electric cars is building a solar array at Frederick County’s landfill, which will power multiple county facilities.
Mike Marschner, the county’s special administrative director and the project manager, said Tesla is building the array of solar panels after three or four years of working through permitting with state and county officials.
The panels, which are being placed on top of a geosynthetic cap at one of the facility’s closed landfill sites, will produce a maximum of about 1.9 megawatts of power. A total of 7,776 photovoltaic modules will produce 3,669,961 kilowatt-hours of energy in the array’s first year — enough to power about 10 county buildings or facilities, roughly 20 percent of the county’s general building power needs, Marschner said.
Marschner said the county entered a 20-year Power Purchase Agreement with Tesla, where it will pay 6.6 cents per kilowatt-hour during that time span. The county is not purchasing additional power through the agreement, but rather using the array versus other forms of energy such as steam or coal.
The power will be routed off the landfill site by Potomac Edison, through a virtual net metering system. That system allows the county to receive solar credits for excess solar power produced.
“The value to us, because you are in this virtual net metering mode, is we don’t pay for certain things that you normally pay for when you’re buying commercial power from the power company,” Marschner said, adding those could be fees and other charges from Potomac Edison.
Aaron Ruegg, a spokesman for FirstEnergy Corp., which owns Potomac Edison, said workers are currently completing off-site work such as fuse upgrades, along with on-site upgrades to connect the array to the company’s power grid.
“In general, any electricity produced by the customer and sent back to the grid offsets any electricity used by the customer during a particular month,” Ruegg said in an email. “Any electricity produced by this project will be used to offset electricity used by Frederick County. The power produced by this solar array will be used by customers near the facility and on the same circuit line as the solar array.”
County Executive Jan Gardner (D) said the array will help the county increase its reliance on renewable energy. Maryland officials want a quarter of the state’s power to be from renewable sources by the end of next year.
“Putting solar on a closed landfill cell is a good thing to do,” she said. “It’s a good location because that land can’t really be used for anything else. And we have to monitor that closed landfill cell in perpetuity.”
Melissa Rocha, a spokeswoman for Tesla, declined in an email to state the construction cost or share why the company was interested in pursuing a solar array at the county’s landfill facility.
General information on Tesla’s website indicates that “an average-size solar panel system generally costs $10,000 — $25,000,” which includes installation costs but does not include rebates or tax incentives.
Marschner said commercial operation of the project is scheduled to start July 1. The project is estimated to be at least 93 percent efficient through its 20-year life span, he added.
The panels could be replaced beforehand, however, depending on how much technology improves.
“New panels that come on the market are better, can produce more energy and maybe have a different rate of decay in terms of output,” Marschner said. “What happens is you wind up replacing them, not because your panels have failed, but because there’s panels that can generate a third more or a half more energy.”