Hybrid bus heads for London
A hybrid diesel-electric propulsion system already in use on more than 1,500 buses in North American cities is to make its European debut on a London bus due to go into service later this year.
The red double-decker powered by BAE Systems’ HybriDrive technology and built by Britain’s Alexander Dennis Ltd was delivered to Transport for London and bus operator Metrobus during the Euro Bus Expo 2008 event in Birmingham.
HybriDrive, already used by transit agencies in New York, San Francisco, Houston, Toronto, and Ottawa, consists of a generator, an electric motor, and a lithium ion energy storage system managed by computerised controls. A diesel engine that turns the generator operates independent of the electric drive motor, allowing it to run at nearly consistent speed for optimum efficiency.
The system uses no mechanical transmission, a major maintenance item on traditional diesel buses, and features regenerative braking that produces electric power while reducing wear on the vehicle’s conventional friction brakes.
“Our hybrid technology is the most proven in the industry, with more than 70 million miles of revenue service to date,” said Rob Lindsey, BAE Systems director of transport systems for the UK and Europe. “Joining with Alexander Dennis brings the combined benefits of improved fuel economy, lower production of greenhouse gases and other emissions, and reduced vehicle maintenance to the transit system and to the residents of London.”