Clean, Zero-Emission Transit ​I​s​ the Future in Suburban Maryland

• Montgomery County, Maryland aims to transition its electric bus fleet to zero-emissions by 2035.
• The county is building microgrids with solar, battery storage, and eventually green hydrogen.
• The microgrids are islands of power that are resilient during outages and emergencies.
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Montgomery County, Maryland, is on the cusp of a clean-transit transformation. 

Part of an old diesel-bus depot in Silver Spring has already been redeveloped into a charging station for dozens of electric buses, powered by a microgrid equipped with solar canopies, battery storage, and several backup gas generators. It’s essentially a self-sustaining island of power, even during outages.

A similar microgrid — twice the size of the one in Silver Spring — is expected to break ground early next year and be operational in 2025, county officials told Insider. The microgrid is set to power a transit center for 200 zero-emissions vehicles and be the first on the East Coast to produce green hydrogen from renewables. Green hydrogen is key for buses with longer routes, officials said, because electric buses average about 125 miles on one charge, or less than half the distance than on a tank of diesel. 

“We are going to transition to a completely fossil-fuel-free transit group with electric and hydrogen buses,” Michael Yambrach, the chief officer of energy and sustainability for Montgomery County, told Insider during a tour of the depot.

The county aims to complete that transition by 2035 for its fleet of 380 buses and nearly 3,600 cars. It’s part of a larger plan to achieve net-zero greenhouse-gas emissions. So far, 14 buses and about 100 cars are electrified.

Yambrach said Montgomery County’s efforts could be a model for other local governments trying to clean up their fleets, which include millions of city buses, school buses, police patrol cars, and other vehicles. Only about 2% of US public buses are zero emission, according to federal data. 

US transit agencies are buying more zero-emission buses and vehicles, but sourcing enough power and building the charging infrastructure affordably are major hurdles.

Montgomery County opted to build a microgrid so it didn’t have to rely on power from Pepco, the local utility. It hired AlphaStruxure, a joint venture of Schneider Electric and the private-equity giant Carlyle, to finance, develop, and maintain the microgrids. In return, the county pays AlphaStruxure monthly under a long-term contract. The company declined to disclose the total cost.

A stand-alone system is more resilient in the event of an emergency outage, Yambrach said. The county has a pilot program with Pepco that allows the utility to tap power from battery storage at the Silver Spring bus depot when the grid is stressed. That is more climate-friendly than relying on firing up a dirty power plant.

Renewable transit also benefits locals’ quality of life by phasing out rows of noisy, idling diesel buses that create a lot of pollution.

“When they light up the buses, the diesel will just hang, and that’s been a consistent issue with the neighbors,” Don Scheuerman, the chief of the office of energy and sustainability at the Montgomery County Department of General Services, said. “So we’re going to have resilience, we’re going to have green power 98% of the time, and we’re getting our greenhouse-gas emissions down.”