BAE Systems’ Series-ER Powers MBTA Buses

ESS-3G-32K (Energy Storage System)
​APS (Accessory Power System)
PCS (Propulsion Control System)

BAE Systems announced that the Massachusetts Bay Transportation Authority (MBTA) has ordered 194 electric-hybrid buses using the BAE Systems Series-ER extended range propulsion system.

Series-ER Enables EV Modes:

Stop/Start: Reduces idling at bus stops for quieter boarding.
Depot Drive: Shuts engine off while maneuvering in depots for improved air quality and noise.
​Extended Range: Allows zero-emission revenue-service driving in designated areas for periods of time.

By moving to a Series-ER system, a fleet can operate a portion of the day electrically with the engine off, reducing maintenance, idling, fuel use and emissions. Transit operators are embracing this technology because it gives them zero emission travel without the need to stop and charge the bus, and it eliminates the need to invest in costly charging infrastructure. Cities like Nashville are using Series-ER technology to drive on battery-electric power near hospitals, schools, and in the downtown tourist area, and Boston plans to use the technology to drive through their tunnels with zero emissions.