When Opel's hydrogen-powered Zafira arrived last week in Cabo da Roca, mainland Europe's westernmost point, it ended a 6,000 mile journey that has set a new distance record for what the US car maker hopes will soon be a standard technology, writes Michael McAleer
Under the bonnet, the Zafira's petrol engine has been replaced with a fuel cell that silently converts hydrogen into water and power for the electric motor. Its petrol tank has made way for a pressurised unit holding enough liquid hydrogen to last for 250 miles.
The technology holds out the promise of pollution-free motoring and so far GM alone has spent nearly €800 million on researching it.
Yet there's no certainty it will improve the environment, nor that the technology can ever be made cheap enough to be commercially viable, let alone by 2010.
The chief obstacle is not the fuel cell itself - although this remains around 10 times too expensive - but the hydrogen. Most of the ways of producing hydrogen require electricity, generated by burning coal or gas; the pollution is simply created by a power station rather than the car. Transporting and storing hydrogen is also problematic and expensive.
The Zafira that crossed Europe used a very large high-pressure insulated tank to store it in liquid form, but still had enough for only 250 miles. "Hydrogen storage is still an invention-dependent aspect of the development," says Larry Burns, vice-president of research and development at GM.
With all these problems, why are the car makers sinking so much money into fuel cell research? "The fuel cell technology can revolutionise the industry," Mr Burns says. "If you are not out there working to create the future and create the future aggressively, your competitors are going to do it first."
He is aiming to put fuel cell cars in showrooms by 2010, and has told GM engineers to bring the cost down tenfold. "Current costs have not had the magic of the auto industry operating at large volumes to engineer money out," he says.