Hydrogen Fuel Cell Propulsion and GM's Hy-Wire

Sustainable Development is a fashionable catchphrase these days. While it may be in the vocabulary only of some, it is certainly an action phrase as far as General Motors (GM) is concerned.

Despite there being millions of vehicles on the road, these belong to only 12 per cent of the world's population. There is, thus, a huge potential for further growth in the vehicular population coming from developing economies. However, if this growth explosion goes unchecked, the impact on the environment would be severe. In an attempt to combine the motorisation of communities with environmental responsibility, GM has set about re-inventing the automobile as we know it.

The internal combustion engine does not see the light of day in GM's new car of the future, one of which in a series of concepts is fondly dubbed "Hy-wire". Instead, the Hy-wire uses a combination of an electric motor and hydrogen fuel cell. This is a refinement of the system as seen earlier on, in the Opel Zafira based HydroGen 3 concept car that was unveiled at the 2001 Frankfurt Motor Show.

With all these real-life concept alternative fuel cell vehicles now here, one could be forgiven for asking when hydrogen fuel cells would become commonplace. Before that can happen, there are some hurdles to overcome.

First, human psychology. People need compelling reasons to buy a hydrogen fuel cell vehicle over a tried and tested internal combustion engine vehicle beyond, say, mere fuel economy. Even if all the car manufacturers offered a wide choice of hydrogen fuel cell vehicles for sale, what would make people choose these over conventional internal combustion engines?

Hence, the alternative fuel cell vehicles must also be affordable to the man in the street, and from the manufacturers' point of view, profitable to develop and build. There is also the concern of the infrastructure, including storage and points of re-fuelling for these vehicles.

Knowing that a hydrogen fuel cell requires two substances for generating power - oxygen and hydrogen - is barely scratching the surface. While oxygen is readily available in the air, hydrogen, which is also abundant, must be harnessed and stored.

It may not take a rocket scientist to figure out how to do these but, it is imperative that it be done efficiently. Just as it is accepted that energy is required to extract hydrogen from the air, continued research and development must be done to minimise the energy required. After all, if more energy has to be utilised to harness hydrogen from the air than the amount of energy that hydrogen can eventually produce, it becomes an exercise in futility.

Ultimately, the cost and affordability of the extraction and storage of hydrogen for fuel cells will determine the viability of the widespread use of these cells as the fuel of the future.

After hydrogen is harnessed, it must be stored. Conventional technology dictates that hydrogen be liquidified and stored as liquid hydrogen in pressurised tanks. Apart from storage capacities, safety is also a concern. With the high pressures under which the liquid hydrogen is stored, the strength of the tanks is critical. Furthermore, the temperatures of the liquid hydrogen must be manageable.

It is a testament to the genius of the research and development team at GM that instead of staring and glaring at these problems, they are now looking at using the very strength of the tanks as part of the structure of the vehicle itself!

Each hydrogen fuel cell is connected together in a series and power is generated from the combined electrical output from each fuel cell to turn an electrical motor for the wheels. Thus, there is no drive train so to speak.

Previously, buffer batteries were used between the fuel cells and the electric motor. Constant research and development, however, has led GM to do away with these batteries in their HydroGen3 concept vehicle. This means fewer components, which in turn means less weight and less volume occupied.

For more power, more fuel cells are needed. The flipside of the coin is that more fuel cells translate to higher vehicle weight and greater volume occupied within the vehicle.

GM has in the Hy-wire, presented to the world a fully functional proof-of- concept car, which may be an important step in the development of alternative fuel cell vehicles. Its transversely installed electric motor drives the front wheels and the re-fueling time is only 5 minutes.

The Hy-wire drew its inspiration from GM's AUTOnomy concept car, which premiered at the 2002 Detroit Motor Show, and showed what fuel cell combined with by-wire technology could do.

"It is a significant step towards a new kind of automobile that is substantially more friendly to the environment and provides consumers positive benefits in driving dynamics, safety and freedom of individual expression," said Chris Borroni-Bird, Director of GM's Design and Technology Fusion Group and program director of the Hy-wire concept.

The Hy-wire is powered by 200 fuel cells stacked at the rear end of the car. Owing to the compactness of the cells, the Hy-wire's all aluminium chassis is essentially similar to a skateboard, with the aluminium being the thickest at the centre, and tapering at the edges. This endows it with a low centre of gravity which aids ride and handling.

The Hy-wire's fibreglass body is attached to this lightweight floorpan at 10 points, making it easy to remove completely for maintenance and repair, or even allowing the owner to change body styles to suit different transportation needs.

Its steering, brakes and other vehicular systems are controlled electronically by wire technology called the X-drive. Conventional floor paddles have been replaced by handgrips. A gentle twist of the left or right handgrip will accelerate the 1900 kg car of the future and braking is accomplished by a squeeze of the brake actuator, ergonomically situated on the handgrip. In fact, the handgrips are the heart of the cabin as they also steer the car by sliding up or down.

By-wire technology also means that the traditional rear view mirrors have been replaced by cameras and vital car functions are incorporated in an electronic monitor that stretches the full width of the cabin.

Apart from offering owners maximum flexibility to customise the body of the Hy-wire, another advantage of the technology is that it simplifies adapting vehicles for both right and left hand drive situations. As there are no hard points required for steering columns and pedal boxes, production is simplified.

The clean, futuristic lines of the Hy-wire is the work of Bertone of Italy, which had designed some of the world's most beautiful cars, such as the Lamborghini Miura. It rides on 20-inch wheels in front and 22-inch items at the rear. This four-door vehicle has no B-pillar between the front and rear doors, giving its cabin and open feeling and making for easier access and exit. The airy feeling is furthered by front and rear panels being made of glass. And it is not just an illusion of spaciousness, for all occupants have a generous amount of room.

"The most dramatic view of this car may be from the driver's seat," said Ed Welburn, Executive Director of GM Design for Body-on-Frame Architectures. "Imagine having no engine, instrument panel or foot pedals in front of you - an open, yet secure cockpit with a floor to ceiling view. The feeling is similar to being in a living room looking out a picture window."

This certainly is a graphic account of what it feels like to drive the future. But, a little closer to the present is the GM HydroGen cars which, based on the body of the Zafira, at least looks very conventional today.

For a car without a "proper" engine, the HydroGen 3 is impressive in achieving a top speed of 160 km per hour. I had the chance recently to try the earlier generation HydroGen 1 at Buttonwillow Raceway at Bakersfield, California.

As expected of a vehicle without an internal combustion engine, there is also none of the noise associated with it. Turn the key, depress the brake pedal, select "D" and it moves off, with literally, a whoosh. Silent as electric motor vehicles go, the Zafira-bodied vehicle has a useful turn of speed. However, one must be careful, for lifting off the throttle for the turns, as one does in a conventional vehicle, does not bring about a noticeable decrease in speed. There is no engine braking, and off the throttle, the vehicle seems to coast on forever.

The strive to have alternative fuel cell vehicles becoming a reality need not take forever; the transition to fuel cell cars will take time, but GM reckons affordable fuel cell vehicles will be a reality by end of the decade. And by 2020, they would be affordable to buy and profitable to build. On the basis of these projections and the technology it possesses, the Hy-wire is certainly a springboard for GM's intention to be the first manufacturer to sell a million fuel cell vehicles before too long.