James Dyson, the UK entrepreneur who re-invented the vacuum cleaner, is turning his attention to a feasible solar-powered car. Dyson technicians based at his Wiltshire brains-trust are working on a design which will carry a whole family for hundreds of miles.

The battery would be charged by solar panels mounted on the vehicle’s roof, or on the roof of a garage where the car is kept. Sir James, whose inventions have made him a fortune worth around £800million, believes electric cars will outnumber petrol ones within a decade.

‘Electric cars are seen as city cars and to go 30mph is quite enough, but in the future that will change. An electric motor can go to very high speeds,’ he said.

The UK’s best-selling electric car, the G-Wiz, costs around 1p a mile to run and is exempt from road tax. But its battery takes eight hours to charge from the mains and lasts just 40 miles. The motor on the proposed Dyson car would be based on those used in the company’s vacuum cleaners and hand dryers.

Dyson is expected to work with an existing carmaker such as Honda, rather than design and build a vehicle from scratch.