Londoners are the first to experience this 100 percent emission-free, purely electric double-decker bus, which was specially developed by the Chinese auto manufacturer, BYD, for the Transport for London (TfL).

The bus was an answer to the London mayor's challenge that such an electric double-decker bus "is not technically feasible." Less than two years later, BYD proved that it can, in fact, be done.

"This is not a hybrid bus, but a totally emissions free product which will give London a world-leading position in its efforts to improve air quality," says Isbrand Ho, Managing Director of BYD Europe.

The bus is the first of the five models of TfL's latest environment-friendly fleet of public transport vehicles. It is fully air-conditioned and can accommodate 54 passengers, with a standing room for 27, bringing the maximum passenger total to 81.

"This a result of a challenge of the mayor to tackle emissions," says Leon Daniels, TfL's managing director of Surface Transport. "The principle driver here is air quality."

Its batteries are made of iron phosphate, and can power the bus for an entire day of average urban driving as per the Standardized On-Road Test standards. One full charge takes approximately four hours.

The bus is built similar to a traditional bus layout for passenger convenience, following the criticism received by TfL's New Routemaster buses, which had several problems including battery and power steering wiring failures. Moreover, the top deck windows of this model do not open, making it a nuisance in the summer.

"Lessons have been learned, like with every new model," says Daniels. "BYD [is] a brilliant supplier. They lead the world in electric bus technology and we thank them for their efforts to make this new double-decker a reality."

BYD is giving TfL and Metroline driving instructions and charging equipment installation assistance.