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."