The BAE Systems Series-ER package means that diesel-electric hybrid propulsion still has a lot left to give and is not yet approaching the end of its life, the company says.
The first Alexander Dennis Enviro400ERs with the BAE Systems Series-ER package recently entered service with Brighton and Hove Buses. They have geofencing to ensure zero-emission operation in certain areas. BAE Systems says that there is potential to significantly extend Series-ER’s engine-off capability.
64kW/h or more of battery capacity is a possibility in the future. That compares with 32kW/h in the current generation Series-ER. A doubling of energy storage would not necessarily mean the same for engine-off range.
Instead, the system could be optimised to give an even longer zero-emission capability. That must be balanced by the impact of restarting the engine after a longer period of being switched off and what it means for the exhaust aftertreatment unit’s temperature.
BAE says despite that, overall emissions of a Series-ER-equipped bus would be no worse than its predecessor the Series-E over the course of a complete route.
The space claim required by Series-ER’s energy storage unit is the same as that for Series-ER. As a result, the newer product can be retrofitted to older hybrid buses.
