Technology Status of Hydrogen Road Vehicles

alliance with Ballard. The 20-kg/kW FC without buffer energy storage allows only modest acceleration, but
improved FC will decrease this to 4-5 kg/kW in the future.
The customer requirements for drive systems are discussed, and mention is made of apparently trivial
problems such as keeping the polymer membrane moist over the temperature range of -30º to +60ºC.
Finally Daimler-Benz estimates of cost trends for PEM FCs are presented as functions of innovation and
production scale. From about the year 2000, a steep rise in quantity and somewhat less steep drop in cost per
kW is expected over about 5 years, dropping off thereafter. The present cost of 80-100,000 DM/kW for
demonstration units should drop to 600-700 DM/kW by 2010.
Studies commissioned by GM and Siemens conclude that FC drives can be manufactured in high unit numbers
for 100-110 or 300-500 DM/kW, figures Daimler-Benz still finds very optimistic.
In conclusion, the fuel infrastructure costs and production engineering are regarded as critically important to
the FC future, whereas the core technical problems of the FC unit and peripherals can probably be solved with
relatively little difficulty.
Bevers, D., et al., “Innovative Production Procedure for Low Cost PEFC electrodes and membrane
structures,” DLR, Stuttgart, Germany, pp. 1767-1776.
A need is identified for mass production of reproducible PEM FC electrodes by a rolling technique well known
for alkaline battery electrodes.
This rolling process was developed with the required potential, and future improvement steps are outlined.
TOPIC 5: Materials and Safety
Linney, R.E.; J.G. Hansel, “Safety Considerations in the Design of Hydrogen-Powered Vehicles,” Air
Products and Chemicals, Pennsylvania, USA, pp. 2159-2168.
Pointing out that on-board hydrogen will bring the public closer to it than any prior application, that the public
is risk-intolerant, and that there are no generally accepted design regulations that cover all aspects of such use,
this paper examines:
! Design considerations focusing on safety
! Flammable mixtures surrounding leaks
! Venting hydrogen from vehicles.
And some real-life situations that could arise.
Quantified risk assessment with the fault tree technique could then lead to an evaluation of the risk to vehicle
occupants and nearby public.
One important result from this paper is that in many real leak scenarios, high release velocities of the H 2 and
normal ambient winds overshadow the buoyancy/diffusivity advantages, so that 5,000 psig H 2 leak can reach
further horizontally than 3,000 psig CH 4.
Pehr, K., “Experimental Examinations on the Worst Case Behavior of LH 2/LNG Tanks for Passenger
Cars,” BMW, Munich, Germany, pp. 2169-2186.
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