Zone-aware taxis will help cut city pollution

London Taxis could be fitted with a GPS unit that automatically switches them to electric power as they enter future designated emission-free zones.

The technology is being considered as part of an investigation into the use of hybrid electric petrol engines by taxi maker Manganese Bronze Holdings, which could see the engines powering black cabs in London by the summer of 2004.

The units are seen as a possible addition to the hybrid engines, in the event of congestion charging zones in London and elsewhere becoming ‘zero emission’ areas, said Ian Pickering, managing director of the company.

The European Commission and national governments are passing increasingly stringent laws to clean up car pollution in cities, so the black cabs are being tested with hybrid engines to ensure the vehicles meet lower emissions regulations in the years to come.

Three taxis will be fitted with the engines for up to eight months, for comparison testing.

Car manufacturers such as Toyota use parallel hybrid systems, where the petrol engine is continuously connected to the powertrain, allowing it to drive the cars on long journeys.

Manganese Bronze is testing ‘series’ hybrid engines developed by Canadian firm Azure Dynamics, in which the petrol engine turns a generator, which in turn powers an electric motor. The petrol engine never directly powers the vehicle.

‘With series hybrid engines, when the vehicle is stationary there is no drain on the batteries and no engine running. Because of this our emissions will be significantly lower, and when the batteries are fully charged the taxi could run with zero emissions. Our vehicle will more than meet all planned emissions regulations,’ said Pickering.