Fuel Cells - Pushing the Limits: New Adventures in Engineering - page 152

of the order of fifty miles per gallon.) By having their batteries charged by the onboard gasoline
engine, hybrids overcome the disadvantages of pure electric vehicles. Also, since the engine runs
at a low and fairly constant speed, high efficiency is matched by low maintenance costs. Daimler-
Chrysler is expected to offer a hybrid pickup truck soon, General Motors has promised to have hy-
brid power in five vehicle models by 2007, and Toyota has announced plans to sell worldwide as
many as three hundred thousand hybrids annually by then. But hybrids are still essentially gasoline-
powered, with the internal-combustion engine being their ultimate source of electricity.
The hybrids thus do not fully address environmental concerns, and they are seen by some ob-
servers as transition vehicles that will ease the radical change from the petroleum-based economy
to the hydrogen-based one assumed to be required for the full-scale adoption of fuel-cell-powered
vehicles, which are currently still in the concept phase. Unfortunately, at least in the early stage of
fuel-cell use, hydrogen is likely to be produced from a hydrocarbon-like natural gas, which is a less
efficient process than that used to convert oil into gasoline for use in a conventional automobile.
The General Motors concept car termed Hy-wire is not only powered by a fuel cell but also
controlled through “by-wire” technology similar to that already widespread in the aircraft industry.
There are no mechanical linkages between driver and throttle, steering, or brakes, since all such
connections are by electrical wire, which leaves room for a more imaginative overall vehicle design.
Since there do not have to be mechanical linkages between pedals and steering wheel and what they
normally control, there do not have to be pedals or a steering wheel at all. Hence, the Hy-wire (a
portmanteau word formed from “hydrogen” and “by-wire”) vehicle is often described as a “skate-
board design,” in which the fuel cell and appurtenances are incorporated into a rather flat chassis,
onto which a variety of body types can be mounted (and changed like clothing to fit the mood of
the owner). Because there are no mechanical linkages between body and chassis, the imagination
of automobile designers is freed up to reconfigure the interior, which can mean a roof-to-bumper
windshield and a handheld control system that is not unlike that of the video-game controllers with
which younger generations have grown up. The concept car is also referred to as the China car,
since it is expected to become available as early as 2008 but no later than 2015, or simultaneously
with what has been perceived to be a potentially booming auto market in Asian countries and else-
where around the world, in which private vehicle ownership currently rests at 12 percent.
Fuel cells are expected not only to revolutionize the appearance and control of automobiles but
also to greatly change the perception of them as noise and air polluters. Since the fuel cell itself has
no moving parts, the only sound associated with its operation is that of the delivery devices needed
to supply the fuel, but reportedly not everyone likes the sound of the compressor in the Ford system.
(A significant lack of engine noise was the most striking feature of the first electric vehicle I rode
in.) Also, since the only by-product is water vapor, in place of smelly exhaust fumes, there will be
but wisps of warm vapor or drips of distilled water. Instead of the present image of internal-com-
bustion vehicles as having developed into greater polluters of cities than the horses that they began
to displace about a century ago, fuel-cell-powered vehicles have the potential for being seen as sa-
viors of the planet—if the problem of generating hydrogen in an acceptable way can be solved.
But fuel-cell-driven vehicles can be successful only if there is an infrastructure in place whereby
they can be refueled. The “hydrogen economy” will become a reality only when the elemental gas