Whatever happened to ... solar cars?

On Monday, Ford Motor Company announced environmentally oriented research of £1bn over the next six years. By focusing on lighter vehicles and hybrid electrical systems it aims to cut down dramatically on CO2 emissions. However, there was no mention of solar-powered cars. "We've never researched them," confirms a spokesperson. "There are other much more viable options."

The solar option did not always seem so unviable. In 1976, an Israeli engineer claimed he had designed the world's first solar-powered car, predicting that the world would take them to heart within a decade. "The trick is to park in the sun, rather than in the shade as your normally would," he advised.

Yet solar-powered vehicles today are only used in competitions, including the World Solar Challenge race in Australia, which is celebrating its 20th birthday next year. In 2005, the Dutch car Nuna 3, which resembled the popular perception of a UFO, drove from Darwin to Adelaide in a record 29 hours and 11 minutes, averaging 63.8 miles an hour.

Competition rules for 2007 have changed to persuade entrants to design more practical vehicles with upright seats and easy access for the driver. The organisers are looking for the "next generation solar car ... which with little modification could be the basis for a practical proposition for sustainable transport".

"My guess is that solar-powered cars will be on the mass market within 10 or 15 years," says Stefan Roest, team leader of Nuna 4. "But the main obstacle is the price." The solar cells on Nuna 4 cost $500,000 (£270,000).

Other solar enthusiasts have encountered different obstacles. In April 1998, John Prescott squeezed into the cockpit of a Honda solar-powered car to promote his green agenda and promptly drove it into a taxi in a Chester car park. In January 2003, the Nuna team visited Scotland as part of a victory tour around Europe. "I don't think Scotland has enough sunshine to produce the power it needs," said one crew member after the car refused to start.

There was some excitement in 2002 when John Jostins, the creator of R2D2 for the Star Wars movies, launched the solar-powered Microcab. Yet the solar panels alone could only generate 150 watts of electricity and the vehicles have subsequently been modified to a hydrogen fuel cell hybrid. "I am, however, designing a solar-powered go-kart for my nine-year-old son," says Jostins, who hopes Microcabs will be used for short urban trips. "He can use it in the summer when the sun is out."

In the meantime, it is interesting to note that increased environmental concerns have turned car choice into an ongoing political issue as well as a commercial concern. Sir Menzies Campbell gave up his Jaguar when he became Liberal Democrat leader. John Prescott hangs resolutely on to his. Government ministers use the trendy Toyota Prius electric petrol hybrid. David Cameron's bicycle is accompanied by support vehicles and BBC helicopters. While at the recent G8 summit, Vladimir Putin drove his American guests around in an electric car. Unlike Tony Blair, he appeared to be sitting in the driving seat.

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