Adapting the site for electrification
Working with an active bus fleet facility that remained operational during construction, Arup's team quickly pivoted to adapt the design to existing conditions and site constraints. This included coordination of existing stormwater management facilities, implementation of equipment structures to reduce the loss of bus parking spaces and working closely with the photovoltaic design team for maximum conduit and trenching efficiency across the site. Adjacent to Meadowbrook Park and Rock Creek stream, it was important to minimise site changes that would reduce existing permeable green space. A steel deck structure on helical piers was designed to hold the 70-ton BESS container, and a gabion wall solution was utilised to level an existing sloped portion of the parking area for the generators.
Sustainable, resilient electrification
We were able to bring our previous experience with bus electrification infrastructure, energy storage and renewable energy systems to the Brookville Smart Energy Bus Depot. The on-site generation components provide resilience and reliability to ensure uninterrupted charging availability for the bus fleet at all hours. Additionally, the microgrid controls will allow multiple operational modes, so the operators can switch between island-mode and grid connectivity. For example, if there are periods when the battery is depleted or the local electric utility grid is down, or generating equipment has maintenance being completed, there are always additional modes to ensure the required fleet vehicles can be charged.
A challenge for electrifying bus fleets is the rapid influx of manufacturers, vendors and competitive products in the market, which was further exacerbated by Covid-19 pandemic supply chain interruptions. Arup was able to respond to equipment changes beyond those originally selected, resulting in improved microgrid performance and increased flexibility to meet future depot demands. The team also coordinated various manufacturers to ensure optimal interconnectivity and regulatory compliance. Additionally, Arup’s knowledge of the local permitting process and previous experience with the local utility proved to be key to effectively moving the electrified bus depot forward.
Electrification brings multiple benefits
As it continues to expand its electric fleet and charging infrastructure, Montgomery County may see advantages beyond reduced carbon emissions and a resilient, reliable bus system. Residents along bus routes served by electrified vehicles will experience cleaner air, and both residents and riders will enjoy quieter buses inside and out. The lower operational costs of an electric bus fleet from the savings on maintenance and diesel fuel, will make funds available to continue procuring additional electric buses.
Paving the way
The Brookville Smart Energy Bus Depot demonstrates a sustainable path for other municipalities and the private sector, allowing them to transition towards electrification and reap the value of a sustainable, resilient, and cost-effective transit system.
As well as cutting carbon emissions, the Brookville Smart Energy Bus Depot ensures a reliable public transportation system for the County. It enables uninterrupted bus services during any long-term power outages caused by severe weather, as well as during any short-term disturbances or perturbations of the utility grid. The county currently has a four-bus pilot program with the plan to increase the fleet in phases up to 70 buses in order to support the Brookville location. Working towards the County's 2035 community-wide carbon neutrality goal, this microgrid implementation will be the first major step in reducing public transportation emissions.
The Brookville Smart Energy Bus Depot’s microgrid and charging infrastructure opened on October 31, 2022.