The key facts:
-Fuel cells are catalytic devices which convert the energy stored in a fuel directly to electrical energy.
-A fuel cell provides the conditions for a catalytic energy release as opposed to combustion. This occurs through the use of an electrolyte which allows the passage of ions, but acts as a barrier to the chemical reactants.
-Fuel cells were devised in the 19th century and were used to provide on-board electrical energy and water for the Apollo spacecraft.
-Fuel cells are capable of high conversion efficiencies which compare very favourably to the thermal efficiency of petrol and diesel engines.
-Fuel cell vehicles are not yet commercially available but the New Vehicle Technology Fund may offer funding for innovative demonstration projects
-Fuel cell vehicles have similar or improved performance as compared to a vehicle with an internal combustion engine. They are not as range-limited as are most battery electric vehicles.
-Fuel cell vehicles can be either ‘pure’ or ‘hybrids’. The hybrid design incorporates the use of a battery for peak power loading. This also enables the vehicle to use regenerative braking which can recover up to 20% of the fuel energy utilised.
-ZeTek Power has a demonstration project involving a fuel cell taxi which has been operating in London.
-Six fuel cell buses have been operational in North America for over two years. Ballard Power Systems (Canadian market leaders) aimed to commercialise fuel cell bus engines by 2002.
-The New Electric Car (Necar) range of vehicles has been developed by DaimlerChrysler, Ford and Ballard.
What fuels can be used by a fuel cell vehicle?
-Fuel cells operate most efficiently if fuelled by pure hydrogen. However, in practice, hydrogen can be delivered to the fuel cell using several fuel routes and air is sufficient to provide the oxygen to the cell. The method for on-board fuel storage is another system consideration. Three fuels (and storage methods) are being actively considered by most fuel cell vehicle developers.
These are:
-Pure hydrogen fuel (stored on-board as a compressed gas). The hydrogen is delivered as required to a fuel cell to provide motive power via an electric-drive train.
-Methanol fuel (stored on-board as a liquid). The hydrogen is generated from the methanol using an on-board reformer as required to provide hydrogen for a fuel cell to provide motive power via an electric drive-train.
-Petrol fuel (very low sulphur formulation; stored on-board as a liquid). The hydrogen is generated from the petrol using an on-board reformer as required to provide hydrogen for a fuel cell to provide motive power via an electric-drive train.
The pure hydrogen option operates at the highest efficiency but requires the development of a new hydrogen infrastructure. The reformer options benefit from existing fuel infrastructures, but are less efficient and more costly than the pure hydrogen option.
Current vehicles available
-No PEM fuel cell vehicles are currently available. However, Ballard and partners have publicly announced bus and car engine launches for 2002 and 2004 respectively. In the UK, ZeTek (formerly Zevco) have developed an alkaline fuel cell taxi and park utility vehicle. This operates in Westminster and is supported by Westminster City Council, Air Products, Shell Hydrogen and TransportEnergy. ZeTek is currently engaging in an international scheme (ZeTek Approved Systems Integrator Programme, ZASIP) to encourage technical and commercial partners to participate in the business opportunity provided by ZeTek’s fuel cell technology.