That was the year when the NEBUS research vehicle - the world's first bus to be equipped with a fuel-cell drive system - was created. After that, the Citaro fuel-cell came, paving the way for the Citaro G BlueTec Hybrid equipped with a diesel-electric hybrid engine. Between 2003 and 2006, a total of 36 fuel cell Citaro buses have been fleet tested as part of the CUTE (Clean Urban Transport for Europe), Ecological City Transport System (ECTOS) and STEP (Sustainable Transport Energy for Perth) programs.
Although this might seem to be just a futuristic concept, the Citaro FuelCELL Hybrid will undergo normal bus duty operations within the framework of a major fleet test in several European cities, just like its predecessors. The new bus technically uses two green powerplant technologies combined into a single vehicle.
The Citaro's regular diesel unit was replaced by a fuel cell drive, while the rest of the major components are shared with the Citaro G BlueTec Hybrid. We mention the electric hub motors fitted to the axles, the lithium-ion batteries and all other electrically powered ancillary components. All this practically makes the new bus move under its own power with no emission nor sound pollution whatsoever, making it more than suitable for congested European cities and metropolitan areas.
The bus's fuel cells are powered by hydrogen just like in the older Mercedes-Benz Citaro prototypes, but this time the novelty is in the hybrid drive's system control unit, which maximizes the fuel economy. This in turn offers benefits in terms of resource conservation and the reduction of emissions associated with producing the required hydrogen. The last part does sound like the future of hydrogen powered fuel-cell buses in each city won't arrive THAT soon, but at least this is a start.