Power for hybrid electric buses

The first of the hybrid electric systems that will power 56 double-decker buses in Oxford and Manchester has been delivered by BAE Systems to bus manufacturer Alexander Dennis Limited (ADL).

Bus operator Stagecoach Group will take delivery of their buses commencing with Oxford first, followed by Manchester, in the summer of 2010. They are the first of up to 300 hybrid electric buses that will be supplied to operators across the UK with support from the Department of Transport’s £30m Green Bus Fund, which provides financial incentives to adopt green technologies.

The diesel-electric BAE Systems HybriDrive system being installed in the new ADL Enviro 400h hybrid buses for Oxford and Manchester will deliver fuel consumption and carbon dioxide emissions that are claimed to be up to 30 per cent lower than conventional buses.

BAE Systems’ HybriDrive technology currently powers more than 2,500 buses in cities across the UK and North America, transporting more than one million passengers every day. So far, these buses have travelled more than 150 million miles, saved 10 million gallons of diesel fuel and prevented more than 100,000 tonnes of carbon dioxide emissions.

‘These new hybrid vehicles are part of a package of measures to make our operations more sustainable and attract people to our greener, smarter public transport services,’ said Adrian Havlin, Stagecoach group technical engineer. ‘We are looking forward to being the first operator of these next-generation buses outside of London.’

The HybriDrive system consists of a generator, an electric motor and an energy-storage system managed by computerised controls. A diesel engine that turns the generator operates independently of the electric drive motor, allowing it to run at nearly constant speed.

The system also uses no mechanical transmission, a major maintenance item on conventional diesel buses.