Car manufacturers have succeeded in developing technology which could see thousands of non-polluting cars on the market within a few years. Environmentalists have welcomed the progress in the development of fuel cell-powered engines, which they hope will eventually replace the internal combustion engine, responsible for creating two-thirds of the world's greenhouse gases.

How it works

The fuel cell is made of two plates separated by a membrane. Oxygen and hydrogen are fed in from either side. The membrane allows only part of the hydrogen atom, the proton, to pass through to combine with the oxygen. The remainder of the hydrogen atom, the electron, passes via an external circuit to the oxygen side, creating electricity. Water is produced when the hydrogen and oxygen combine.

The fuel cell uses the energy in the fuel almost twice as efficiently as a normal engine. It can also deliver electric current for air conditioning or heating systems. Unlike battery-powered electric cars, fuel cell-powered cars achieve similar ranges and load-carrying capacities to conventional cars with combustion engines.

A for endurance

In the United States, DaimlerChrysler's NECAR 5 (New Electric Car) completed a thirteen-day, 4,800km endurance test drive from San Francisco to Washington. The car is a Mercedes-Benz A Class vehicle powered by a fuel cell engine which generates 75 kilowatts of power. The hydrogen is generated onboard the car from methanol liquid.

Car manufacturers involved in developing fuel cell technology hope that methanol will soon be able to be dispensed in the same way as petrol (gasoline) at pumps. It is the first fuel in the 115-year history of the car in Europe that can be produced from renewable sources.

A black day for the oil industry?

DaimlerChrysler's NECAR 5 has met with the approval of several members of the United States Congress who want to promote the new technology with tax incentives. They believe fuel cell technology is not only environmentally sound, it could also reduce countries' dependence on imported oil. That's important given that diminishing supplies of fossil fuels are expected to lead to higher oil prices.

DaimlerChrysler, which has announced it will co-operate with other German car manufacturers BMW, Opel and Ford to develop alternative power-production sites, plans to have fuel cell-powered passenger vehicles on the market by 2004.