13 Jul 00
It's an alternative to the internal-combustion engine that doesn't rely on impractical battery power. Given that fossil fuels are predicted to run out in the next 30 years, it offers a realistic hope for the future of personal transportation.
The motive unit is an electric motor powered by a fuel cell. The fuel cell is a clever, but essentially simple, device that produces electricity by a chemical reaction between hydrogen gas and air. During the reaction, electrons - the particles that hurtle through wires to give us electricity - are given off and collected to be used to power an electric motor. The only by-product of this process is harmless water.
The chemical reaction to make the electricity takes place across a platinum catalyst - a bit like the device that scrubs the muck out of a petrol engine's exhaust. But instead of being tubular to fit inside an exhaust pipe, the fuel cell is ultra-thin. Each cell generates about 1 volt of electricity, so the cells are connected together in series. A family car needs about 200 volts, so a typical stack would contain 200 cells.
There's a race on among all the major manufacturers to get the first fuel-cell car to market. Honda has placed its first fuel cell vehicle with a private family, and plans to start commercial sales shortly; all the major car companies are promising sales within the next few years (albeit mainly in the USA) and most have test fleets up and running.
