London black cabs are going green

It looks like a traditional black taxi - but it is actually very green.

The pioneering "Fuel Cell Black Cab" gives a glimpse of how hydrogen technology could clean up air quality in cities.

The vehicle, unveiled yesterday at London's City Hall, is powered by a hydrogen fuel cell system and lithium polymer batteries.

Capable of achieving a top speed of over 80 mph, it has a range of more than 250 miles on a full tank of hydrogen and so it can operate for a full day without the need for refuelling. Furthermore it refuels in about five minutes and produces no emissions other than water vapour.

London's deputy mayor for policing, and chair of the London Hydrogen Partnership, Kit Malthouse, said: "The black cab is a much-loved London icon, but it is also a significant source of pollution, especially in the centre of the city.

"This prototype Fuel Cell Black Cab, which emits only water from its tailpipe, is an exciting glimpse of how hydrogen technology could soon play a vital role in cleaning up air quality for urban dwellers."

Later this year, Transport for London will start operating five hydrogen fuel cell buses, and London Mayor Boris Johnson is working with manufacturers to ensure all taxis operating in London have zero exhaust pipe emissions by 2020.

The cab has been developed by clean power systems company Intelligent Energy, automotive engineering consultancy Lotus Engineering, taxi manufacturer LTI Vehicles and product development company TRW Conekt, with funding from the government's technology strategy board.

The taxi is not yet commercially available and is undergoing track and road testing.

It will also need to meet the London Public Carriage Office rules for use as a taxi on public roads.