Technology Status of Hydrogen Road Vehicles

Such a development also smooths the path for FCs, which are expensive and easier to assemble at present in
reduced sizes. So an FC only one-fourth the size of that required in a non-hybrid bus may be attractive,
depending on cost trade-offs between the FC and the energy storage device.
Wurster et al. (1996) describe two buses for near-term demonstration, of direct interest to this question: the
Neoplan one mentioned above with a flywheel energy storage (Item 10 Table 2) and a similar MAN city bus
(Item 11 Table 2) in which a 120-180 kW PEM FC provides all power; they will be demonstrated in parallel
in the same city.
Schock et al. (1996) find hybrid vehicles particularly suited to compete with conventional automobiles in
California. A small, constant-speed ICE with suitable buffer storage (flywheel, ultracapacitors, and batteries
are mentioned) gives similar performance to conventional automobiles, and allows “equivalent” ZEV standard
(