Mortenson is thrilled to announce our assignment as the engineering, procurement, and construction (EPC) partner for the Montgomery County David F. Bone EMTOC (Equipment Maintenance & Transit Operation Center) fleet depot EV charging and microgrid project in Derwood, Maryland in strategic partnership with AlphaStruxure as the project’s developer.
This partnership mirrors the successful collaboration of the Brookville Smart Energy Bus Depot, where AlphaStruxure led as the developer and Mortenson as the general contractor. Montgomery County’s first fully constructed microgrid-powered bus depot, the Brookville Smart Energy Depot was completed in 2023.
The EMTOC microgrid will include up to 2.25 MW of electric bus charging capacity powered by 5.5 MWDC of rooftop and canopy solar generation, 2 MW battery energy storage, and existing backup generation, along with plans for an on-site 1 MW hydrogen electrolyzer.
“Mortenson looks forward to continuing to build on our relationship with AlphaStruxure and Montgomery County to bring this monumental project as the largest self-sustaining bus depot in the nation to fruition,” said Brian Abeld, Vice President, General Manager for Mortenson. “We are excited to share our unique energy and infrastructure design-build experience to execute the EMTOC project and are humbled to know the long-term, positive impact it will have on the community of Montgomery County, the industry, and our planet.”
The microgrid will not only power a mixed fleet of battery electric and fuel cell electric buses but also the EMTOC campus’ five existing buildings, ensuring uninterrupted service in the event of a loss of utility power. It is engineered to operate in island mode indefinitely, guaranteeing the County’s operations during extended power outages, thereby enhancing the project's reliability and the community's resilience.
As the project's EPC partner, Mortenson plays a crucial role in coordinating with all stakeholders to ensure alignment and clarity throughout the design and construction processes. Leveraging our extensive engineering and construction experience in electric vehicle charging infrastructure, utility interconnection, battery energy storage, solar, and power delivery solutions, Mortenson is committed to creating more than just a facility.
“We are building a thoughtfully planned, state-of-the-art project that will set new standards in the industry while delivering a seamless experience for our customer,” Erin Saewert, Director of Operations for Mortenson.
The EMTOC project is a pivotal stride toward Montgomery County’s ambitious goal of achieving 100% emissions reduction by 2035 by reducing emissions from public transportation while bolstering the community's resilience and infrastructure assets. By 2035, the facility is projected to house over 200 zero-emissions buses.
“It’s a joyous moment to be breaking ground on a project that is the new standard for public transit in the United States,” said Juan Macias, CEO of AlphaStruxure. “The County has proven itself as a national leader in zero-emissions transit, in part by prioritizing simultaneous procurement of both the buses and the sustainable infrastructure needed to power them. Both are fundamental to a successful fleet transition. Our Energy as a Service approach enables the County to achieve sustainable and resilient transit — without upfront capital, in a way that de-risks the financial, construction, and operations phases of the project.”
When completed, EMTOC will be the largest renewable energy-powered transit depot and transit microgrid in the United States.
The project recently broke ground, and operations are expected in Q4 2025.