BAE Systems announced that the Massachusetts Bay Transportation Authority (MBTA) ordered 194 electric-hybrid buses using the BAE Systems Series-ER extended range propulsion system. As transit agencies continue to advance toward more electric systems to help them meet their environmental goals, the demand for BAE Systems’ reliable and efficient hybrid-electric systems continues to grow. Half of the 10,000 system deliveries were made in the past three years, demonstrating a rising trend for BAE Systems’ propulsion systems.

The company is delivering its Series-ER system with a higher capacity battery to help Massachusetts reduce emissions and noise pollution on its transit bus routes. The Series-ER system, which uses electric motors instead of diesel engines to power the buses, builds on the company’s proven technology that is saving more than 22 million gallons of fuel and 250,000 tons of CO2 each year across the globe.

Traditionally, a transit bus powers its wheels with a diesel engine, which produces harmful emissions and uses large amounts of fuel. Instead, electric-hybrid buses are propelled by an electric motor, with power provided from a highly efficient battery system. The battery is recharged by both an on-board generator set, using a down-sized internal combustion engine, and by regenerative energy produced when the bus slows to a stop. 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, according to BAE.

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.