An array of solar panels, spreading across nearly five acres at the Back River Wastewater Treatment Plant in Essex, could deliver significant energy savings and will pay for itself within a decade, officials said Tuesday.
The 4,200 American-made panels, installed in the past three months at a cost of about $4 million, have begun to supply about 5 percent of the energy — up to 1,000 kilowatts per hour — needed to run the plant on Eastern Avenue.
The plant serves about 1.3 million residents in the city and Baltimore County and can treat 180 million gallons of sewage a day. It uses the methane byproduct from its treatment process to produce about 20 percent of the power for its equipment.
"Altogether, that is 25 percent of the power coming from renewable resources," said Mayor Stephanie Rawlings-Blake. "This project promises to save the city millions."
City and county officials gathered in front of the solar array for a ribbon-cutting Tuesday and lauded the energy-saving, cost-cutting technology.
A $900,000 grant from the Maryland Energy Administration, a state agency dedicated to green energy initiatives, helped launch the project. Johnson Controls, the contractor, has guaranteed that the city will recoup construction costs. The equipment is expected to last at least a quarter-century.
Malcolm D. Woolf, director of the Maryland Energy Administration, said the implications of solar power are far-reaching given the age of the state's infrastructure. About 70 percent of the treatment plants are more than 30 years old. Built in 1907, the Back River plant is one of the oldest and largest sewage operations in the state.
"Decisions made today will be with us for decades to come," Woolf said. "The solar industry employs 2,000 workers and is doubling the amount of solar on the grid every nine months."
From its 466-acre site on the western shore of the Back River, a Chesapeake Bay tributary, the plant operates around the clock to prevent sewage from seeping into the river and bay, said Baltimore County Executive Kevin Kamenetz.
"We are separate jurisdictions, but we share the same environment and the same watershed," Kamenetz said, noting that the county also will realize savings from the plant's use of solar energy.