German version

The new MAN fuel-cell bus - yet another milestone towards ensuring future mobility.

As part of the "Five Years of Hydrogen Project at Munich" jubilee, the MAN Nutzfahrzeuge Group is presenting a recently developed low-floor scheduled-service bus with hybrid fuel-cell drive. The electric engine is supplied with 68 kW from a PEM fuel-cell system and over 100 kW from an energy storage system. The electric storage unit makes it possible to reduce fuel consumption by using the brake energy. The bus is initially being used for test operations on the airport apron. There are also plans for it also to be deployed on local public transport routes close to the airport.

MAN hydrogen buses

MAN publicly introduced the first worldwide bus with liquid hydrogen storage and a combustion motor as early as 1996. This was followed by a two-year test run in regular local public transport in Munich and Erlangen.

In the middle of 1999, MAN started to test three low-floor articulated buses with a compressed hydrogen combustion engine. Since then they have been used in passenger transport on the apron of Munich Airport, during which time they have covered over 300.000 km.

A further MAN hydrogen bus went into operation in Berlin at the end of April.
Thanks to a total performance of over 350,000 km MAN has impressively proved that drive technology with hydrogen as fuel is well suited to day-to-day operations.


MAN fuel-cell buses

The first MAN fuel-cell bus was introduced in May 2000 and successfully completed six months of scheduled-service operations in the metropolitan area of Nuremberg.

Eberhard Hipp, Manager of the MAN Advance-Development department commented: "Since the practical tests give us extensive knowledge for further development, it is important for us to deploy the hydrogen technology early at a practical level. All the hydrogen buses we have introduced have been completely integrated into the operators' fleet and driven and fuelled with fuel by the bus operator's personnel."

Fuel cells and energy storage

The MAN fuel-cell low-floor scheduled-service bus is being introduced with a novel concept.
Our development partner is Ballard Power Systems in Kirchheim. This company is recognised as the market leader in PEM fuel-cell technology. Amongst the various types of fuel cells, PEM fuel cells (PEM = Proton Exchange Membrane) are especially well suited to mobile usage thanks to their low operating temperatures of 60-80° C and high-level efficiency. Given that the development focus is on systems for high-volume motor car markets on account of higher quantities, the targeted costs are likely to be achieved in good time.

because the urban bus market sector is not large enough to generate the effects which are both helpful and necessary for development-intensive technologies such as fuel-cell power.

What makes the hybrid fuel-cell bus so special is the combination of a car fuel-cell system with a maximum electric rating of 68 kW and a high-performance energy storage unit.

A further advantage is possible thanks to the combination with an efficient energy storage system: the return storage of brake energy. MAN has already been able to demonstrate the consumption-reducing effect of the brake energy usage in a diesel/electric bus. A nickel metal hybrid high-power battery serves as the energy storage unit.

Electric drive and hydrogen as fuel

Based on the central engine concept, the electric motor is characterised by high ride comfort, low-noise operations and smooth drive off and is thus particularly suited to vehicles deployed in towns.

The hydrogen is stored in gas form at 350 bar in cylinders on the vehicle's roof and supplies a daily requirement with approx. 39 kg. This
covers a range of over 300 km and is the equivalent of approximately 140 l.

An essential advantage of fuel-cell drive systems is the high level of efficiency in the part-load sector. Nowadays system efficiency levels of up to 50% can be achieved and there is room for further development potential.
Both the high ride comfort and the low part-load consumption make fuel cells attractive for urban vehicles.

The fuelling of buses is comparable to that of natural-gas buses and completely hitch-free. Fuelling time depends on the system technology at the airport fuelling station. It takes less than ten minutes to refuel the storage system with a total volume of 1640 l.

The fuel-cell bus has been extensively tested by the TÜV (German technical advisory organisation) and released for public transport authority operations, including parking in garages, without any restrictions.

Future-oriented drive concept

MAN regards fuel-cell drive as a future-oriented option with the potential of establishing itself particularly as a drive system for vehicles in local public transport. Essential prerequisites for this are further technological developments in order to meet the requirements for wide-scale market introduction. Series production of fuel-cell drive in buses can be expected in about ten years' time.

For further information go to:

Alwin Berti
Communication Manager Product and visual Media
Tel.: +49 (0)89 1580-2485
Fax: +49 (0)89 1580-912485
e-mail: Alwin_Berti@mn.man.de

 

Munich, May 2004

 

 

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