A Wacky Races convoy of solar cars has set off on a gruelling 2,000-mile race through Australia’s outback.

The World Solar Challenge race from Darwin to Adelaide is expected to take about a week for most of the 42 vehicles competing.

Powered only by the sun, the cars can reach speeds of between 55mph and 62mph (90kph to 100kph).

Reigning champions Nuon from Delft University of Technology in the Netherlands are hoping to retain their prize.

Nuon’s tour manager, Sarah Bennink Bolt, said: All the cars look completely different (this year), and all we know is we’ve got a good car, we’ve got it running perfectly the last couple of days and we’re confident we’re going to do everything to win.

Belgian team Punch Powertrain earned the right to start first on Sunday after a trial time of two minutes and three seconds over a 1.78 mile (2.97km) course, hitting an average speed of 51.5mph (83.4kph).

A British entry built by a team at Cambridge University had to withdraw before the event started because the vehicle was damaged during testing.

The Cambridge University Eco-Racing team’s Mirage car rolled after suffering a sudden loss of dynamic stability – leaving it with irreparable damage.

The driver, who was protected by the car’s safety compartment, was treated for minor abrasions and fractures in hospital.

Race director Chris Selwood said the biennial event has attracted one of the best fields ever, with teams from more than 40 countries competing over 1,864 miles (3,000km).

He said: This is the 30th anniversary of the Bridgestone World Solar Challenge and competitors want to be part of that. They have been drawn to the challenge of new regulations which reduced the solar array size without limiting the size of the solar car.

Teams from countries including the US, Japan, Germany, Chile, the Netherlands, Malaysia, Belgium, Sweden, Iran, South Korea, India, Hong Kong, South Africa, Poland, Thailand, Turkey, Canada, Taiwan and Australia are taking part.

(c) Sky News 2017: Solar-powered Wacky Races convoy takes on 2,000-mile outback challenge