Two years ago we reported that London’s iconic black cabs would be getting a green makeover with a fleet to be fitted out with zero local emissions hydrogen fuel cell power systems in time for the Olympics in 2012. Now the first prototype fuel cell black cab has been unveiled. It is powered by hydrogen fuel system hybridized with lithium polymer batteries that allow the vehicle to operate for a full day without the need for refueling.

The prototype cab is capable of a top speed of over 80 mph (129 km/h), has a range of more than 250 miles (402 km), refuels in about five minutes and produces no emissions other than water vapor.

The first cab off the rank was unveiled at London’s City Hall by London’s Deputy Mayor for Policing and Chair of the London Hydrogen Partnership, Kit Malthouse.

“The black cab is a much loved London icon, but it is also a significant source of pollution especially in the center of the city," said Malthouse. "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.”

The prototype black cab was a team effort, with Lotus Engineering packaging the full propulsion system including the fuel cell engine from Intelligent Energy and designing control systems to optimize performance of both the fuel cells and electric drive systems. TRW Conekt led the safety analysis program, including braking and steering systems, and London Taxis International Limited (LTI) provided donor vehicles to assist with the structural modifications to the chassis of the taxis.

The Intelligent Energy fuel cell system has been integrated into the most recent LTI TX4 model taxi, and fits into the vehicle without intrusion into its internal or luggage space.

The first fleet of fuel cell black cabs is due to be introduced in time for the London Olympics in 2012. Later this year, Transport for London will start operating five hydrogen-fuel cell buses, and the Mayor of London, Boris Johnson, has committed to working with manufacturers to make all taxis operating in London zero tail-pipe emissions by 2020.