Montgomery County, Md., and AlphaStruxure broke ground on an integrated microgrid infrastructure project, featuring electric bus charging and on-site green hydrogen production powered by solar and battery energy storage.

Keying in on Zero Emissions

The County operates the second-largest bus fleet in the Washington, D.C. region. Its David F. Bone Equipment Maintenance and Transit Operations Center is a major depot within Ride On Montgomery's network and the fifth largest County-owned energy consumer.

By 2035, the depot is projected to accommodate 200 zero-emissions buses, of which most will be hydrogen fuel cell electric buses (FCEBs).

Microgrid Construction

The microgrid's construction is expected to be completed in 2025, when the system will begin sending renewable energy back to the grid and have the ability to power zero-emissions buses.

The microgrid follows the launch of the Brookville Smart Energy Bus Depot in 2022, which was the County's first fully constructed microgrid-powered bus depot and also led by AlphaStruxure.

Together, the two depots will eventually power about 335 zero-emissions transit buses, according to the County's latest fleet transition plan.

100% Zero Emissions Goal

Fueling the County's FCEBs with green hydrogen produced by the microgrid's solar array advances the County's goal of reaching a 100% reduction in carbon emissions by 2035.

The microgrid also enables the County to reduce its Scope 1 and 2 emissions by 4,000 metric tons of CO2 per year, equivalent to approximately 780 homes' annual electricity use. The County will also use the microgrid to advance equity.

The microgrid will support zero-emissions buses for cleaner air and less congestion along its bus rapid transit (BRT) network, which serves many minority and low-income riders. It will also support new career and training opportunities for underserved communities through a County apprenticeship program.

Like the Brookville depot, this existing depot will remain fully operational throughout its 28-phase construction process, with no impact on transit services.

The microgrid will provide sustainable, resilient power to a mixed fleet of battery electric and FCEBs, along with the facility's five buildings. It will also be interconnected to the Pepco utility grid and is engineered to operate in island mode indefinitely, ensuring uninterrupted service for the County's constituents during extended grid or power outages and emergency situations.

Specifically, the microgrid will include:  

• 5.65 MWDC of rooftop and canopy solar generation.

• 2 MW/6.88 MWh battery energy storage.

• Up to 2.25 MW of charging capacity.

• 1 MW hydrogen electrolyzer.

• Software tools and IoT-connected hardware.

AlphaStruxure and the County will leverage a close partnership with the local utility, Pepco, to deploy the large-scale microgrid on a rapid timeline.

In addition to powering on-site production of green hydrogen, a resilient fuel source for FCEBs, the microgrid will also be able to send up to two megawatts (MWs) of renewable energy back to the utility grid via a Pepco net metering program.