The world solar challenge car race began on Sunday morning: as 37 teams drove out of Darwin at the start of a 3000 kilometre road trip across Australia. The biannual race sees solar-powered electric cars and vehicles traversing Australia’s interior. As solar technologies and aerodynamics of the cars have advanced, race sponsors have adjusted how much solar the cars could have on them, their size and even how fast the cars can go – they now have to follow posted speed limits and incur time penalties when caught over the limit