P3 microgrid infrastructure powers county's electric bus fleet, reduces lifetime emissions by 62%

In the face of growing impacts due to climate change, Montgomery County responded by doubling down on its goals of energy resilience and sustainability.

To improve its energy resilience in light of a history of extended power outages due to storms, the county built two microgrids to maintain essential service provision to the community in the event of a large-scale power outage. As proof of its commitment to sustainability, the county set a goal of achieving net-zero emissions by 2035.

Having set its own net-zero emissions goal, the county needed projects that would take steps to reduce the reliance on fossil fuels. Inspired by the State of Maryland’s goal to have a 50% zero-emission bus fleet by 2030, Montgomery County resolved to electrify 44 buses from its fleet.

The only question that remained was how to build the infrastructure necessary to power the new vehicles in a sustainable, resilient manner.

The city utilized a public-private partnership that used an energy-as-a-service financing model to build out its microgrid system.

The county had previously built two microgrids to maintain service provision during power outages. When thinking of ways to build and power charging infrastructure for the new electric fleet, one option stood out: a sustainable, resilient microgrid system.

Through a public-private partnership (P3) with AlphaStruxure that used an innovative energy-as-a-service financing model, Montgomery County plans to have the new microgrid operational in 2022. The P3 service model enables AlphaStruxure to design, own, and maintain the microgrid while allowing the county to nearly eliminate all upfront costs. The project will ensure a ready supply of sustainable, resilient, and cost-effective power for the County’s new electric bus fleet.

The project was named the Brookville Smart Energy Bus Depot (BSEBD). Generating 5.6 MW of power, the depot’s microgrid will ensure uninterrupted service of the 44 bus fleet even in the event of multi-day utility grid outages. Once operational, the microgrid will generate electricity through solar PV canopies constructed over the bus parking lots as well as through other carbon-neutral sources, and funnel the electricity into battery energy storage and electric vehicle charging equipment.

Through the BSEBD, Montgomery County will have a resilient, powerful source of 100% renewable electricity that can be directed in or out of the microgrid to nimbly support either the bus depot or the main power grid as needed. Furthermore, by charging from its own power supply, the county will avoid utility demand charges and won’t have to set bus charging schedules around the utility’s time-of-use rates. The project will be operated via a cloud-connected network operation to monitor and optimize energy performance.

“This bus depot is one component of many county projects that are making a difference for our environment such as converting our fleets to electric and reducing harmful emissions,” said Marc Elrich, county executive. “This infrastructure project will improve the county’s resilience, and we are proud to be at the forefront amongst local governments when it comes to projects like this.”