Volkswagen displays the Bora HyMotion and Bora Electric in Berlin

Volkswagen is displaying its Bora HyMotion with fuel-cell propulsion and also the Bora Electric with battery and electric motor at the 18th Intn Electric Vehicle Symposium and Exhibition from October 21 to 24, 2001 in Berlin. This exhibition is the largest event of its kind in the world for vehicles using alternative forms of propulsion.

Both Volkswagen cars are designed as ¿zero-emission vehicles. The fuel cell converts hydrogen and oxygen into electrical energy that is used to power an electric motor. The only residue from this process is water vapour. The Bora Electric's traction motor is driven by a battery that is recharged from a mains supply socket.

The HyMotion's fuel cell is the key element in its propulsion system. A fuel cell operates at higher efficiency than an internal combustion engine, especially when the vehicle is being driven at part-load, the situation that occurs most often in day-to-day driving. The fuel-cell car's fuel tank contains 50 litres of liquefied hydrogen at a temperature of minus 253 Centigrade. This amount of fuel is equivalent to the energy content of 12 litres of petrol (gasoline) and is therefore sufficient for an action radius of about 350 kilometres. The 75-kW asynchronous electric motor runs smoothly, without vibration, and thus ensures pleasant, relaxed driving. With a torque of 255 Nm over a broad speed range, it accelerates the HyMotion from 0 to 100 km/h in 12.6 seconds and thence equally briskly to a top speed of 140 km/h.

The Bora Electric's driveline power rating can be varied according to operating requirements. Depending on the chosen specification, it can reach 100 km/h from a standstill in 12 seconds or a top speed of up to 140 km/h. The energy needed for this is taken from a Li-Ion battery weighing 300 kilograms, the most advanced battery technology so far available.

The notable feature of electrically propelled vehicles is that they do not produce any local pollutant emissions. Their noise emissions are also extremely low, making them ideal for use in emission-sensitive zones such as inner city areas. However, the battery-powered electric vehicle cannot be regarded as a potential high-volume source of energy for automobiles in view of its overall energy balance-sheet and its limited operating potential. Its use in various market niches, however, seems perfectly practicable.

Of all the alternative types of vehicle, those with a fuel cell running on hydrogen seem likely to make the biggest contribution toward reducing environmental burden - provided that the hydrogen they need can be produced by a regenerative form of energy. In addition, before vehicles can be built in significant numbers and can establish themselves on the market, the technological barriers that currently exist with regard to the production, distribution and storage of hydrogen must be overcome. For this task, Volkswagen estimates that up to 15 years will be necessary.

Supplied by Pete Frost