Australia's Arrow-1 solar car at the start line of the World Solar Challenge 2013 in Darwin on Sunday, October 6, 2013.
A team from Holland's Delft University is leading the world's toughest solar car race at the end of its second day.
The Nuna 7 was just a few minutes ahead of a vehicle developed by Japan's Tokai University as both parked for the night. The cars have made it 1,300 kilometers across the Australian desert in two days and must travel a further 1,700 kilometers to the finish line in Adelaide.
The race traverses some of the harshest desert in the world. There's plenty of sunshine to power the cars, but high temperatures and long days make the World Solar Challenge a test of endurance. Eleven cars have given up, leaving 18 to compete in the challenger class of the race.
The Delft University team would have been further ahead but it incurred a 10-minute penalty Monday at Tennant Creek for failing to observe changing speed limits. The Tokai University team almost suffered a similar penalty, for incursions by a media car, but the car was ruled to be independent of the team and the penalty was lifted.
Both Delft and Tokai universities are no strangers to the top of the leader board. Delft won the World Solar Challenge in 2001, 2003, 2005 and 2007, and Tokai won in 2009 and 2011.
But there's a lot of racing before either team can feel confident about finishing, let alone winning.
Seventy-eight kilometers behind the second-place car is Solar Team Twente, also from the Netherlands, and in fourth place, a further 15 kilometers back, is the team from Stanford University. The University of Michigan rounds out the top five in the challenger class.
In the "cruiser class," in which vehicles have to meet road-worthiness regulations for their home countries, the Powercore SunCruiser holds the lead, built by the Hochschule Bochum Solar Car Team from Germany.
"Stella," the world's first solar-powered family car, is in second place in the cruiser class. It was produced by a team from Eindhoven in the Netherlands. The University of New South Wales gives the Aussies something to cheer about in third place.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is martyn_williams@idg.com