These zero emmision, Hydrogen fuel-cell buses will be in operation over a complete London Bus Route, testing day to day viability of the technology.
The total vehicles has now reached eight with the last one arriving yesterday (26 September).
Five arrived by 2012 leaving the last three to be delivered during 2013.
London has also committed to maintaining the refuelling infrastructure which will support these vehicles in service.
Lea Interchange Depot was chosen to operate these vehicles on the RV1 route and a large refuelling facility was incorporated into the depot with a workshop to maintain the vehicles.
The current contract was signed by TfL (Transport for London), ISE and partners for £9.65m. This covers not only the initial cost of the vehicles but also the specialist maintenance and replacement parts over a five year period after delivery.
TfL have also signed a contract with Air Products to maintain the 300kg/day refuelling facility and to supply compressed hydrogen for the buses
Zero-emission fuel cell-powered buses deliver environmental benefits, when compared to traditional diesel hybrid systems. Fuel cell buses emit only water vapour, eliminating air pollutants such as nitrogen oxides, sulphur oxides and particulate matter. Fuel cell buses can also significantly reduce greenhouse gas emissions on a “wheel to wheel” basis when compared to conventional technologies.
A fuel cell works using a proton exchange membrane (PEM) Hydrogen is on one side of the PEM and oxygen on the other. The PEM allows hydrogen protons to pass through but does not allow the electrons. These electrons pass round a circuit, providing the bus with electricity, to re-join the hydrogen and oxygen atoms producing water.
The hydrogen fuel cell buses operated by Tower Transit for TfL use a hybrid electric system with the hydrogen stored in tanks on the roof.
The only emission from a fuel cell bus is water, which forms a vapour cloud as it leaves the exhaust as it enters the atmosphere.