One of the
first applications for fuel cells based on their advantageous properties was
in the US space program.
Three alkaline fuel cell modules supplied 12 kW electric power each
during the Apollo missions in the 1960's. In 1970, Professor
Karl Kordesch of the University of Graz, Austria, developed the first
officially approved fuel cell powered car. It was a hybrid car with a 6 kW alkaline fuel
cell, lead-acid batteries and a 20 kW DC electric engine. Since then, the field
of mobile applications has increased to include almost all kinds of motorised
transportation, by sea and air as well as land. Examples of ongoing projects are
the application of fuel cells in submarines, ferries, aircrafts and
mopeds. Fuel cells are not seen to be suited in all cases as the main
power supplier. They are also considered interesting as an auxiliary
electric power supply in combination with combustion engines. Without doubt, the automobile industry is the most
active fuel cell actor, investing billions of
dollars each year in research and development.
Hybride fuel cell car from Kordesch,
GM Opel Zaphira Fuel Cell car.
vehicle manufacturing companies are involved in fuel cell
research. During the last few decades, more environmentally friendly alternatives to the internal combustion
(IC) engine has been sought. Strong governmentalregulations,
especially in California, USA, have undoubtedly accelerated the introduction
of fuel cells into cars and buses. Compared to IC engines, fuel cells have
practically no polluting exhaust like NOx and sulphides. The
amount of carbon dioxide depends on the chosen fuel. Since the
overall efficiency is higher for a fuel cell system, this is always less than in a combustion engine.
Fast response times (acceleration) and
start-up times are among the most important
requirements for automobiles. High-temperature fuel cells, like MCFC and
SOFC, are not well suited as their systems are more complicated and have a
considerably longer start-up time than the PEMFC and DMFC. A problem
which has required much effort to solve is operation below zero degrees. Since the polymer membrane contains large amounts
of water, precautions have to be taken to prevent the stack from
PEMFC with methanol
reformer, Necar 5 by DaimlerChrysler.
Inside of the Necar 4, DaimlerChrysler.
of the Necar 4 from DaimlerChrysler is shown in the centre picture above. It
can be seen that the fuel cell stack itself is only a small part of the
overall system. An air compressor, pumps, gas humidifier and a control unit
with a DC-DC converter are needed to assure stable and safe
operation. The small amount
space in vehicles sets tough limits for the implementation of complete
systems. Several parts have to be specially developed to fit into today's car
design. In the case of a PEMFC system the storage of hydrogen is still a problem. None
of the pressurised gas, liquefied gas or metal hydride options have
proven their suitability. Another approach is to store liquid methanol and use
a reformer or a direct methanol fuel cell, which has a lower power
Citaro bus, DaimlerChrysler and
Toyota FCHV-4, hybrid
Focus fuel cell car.
is generally acknowledged that the feasibility and durability of fuel
cells in automobiles has been proven. The major
focus now is on cost reduction. Here, the amount of precious metals and the
polymer membrane are the dominating factors. DaimlerChrysler, GM,
VW, Volvo, Ford, Toyota, Honda and others have joined forces with the Canadian fuel
cell company Ballard in the development of fuel cell cars. GM have announced
the introduction of their fuel cell cars in 2010. The next five years will
show who will win the commercialisation race.