While experts debate the efficiencies of hybrid and plug-in electric cars, teams from around the world are looking to bypass the plug or pump altogether and tap the sun for energy. Sponsored by Bridgestone, the World Solar Challenge invites teams to build solar-powered cars and race them across Australia’s outback along a 3000-km course from Darwin to Adelaide. Held October 6-13, the seven-day journey pushed these enthusiastic innovators to their physical and intellectual limits. The competition included 38 teams from 23 countries in three classes based on speed, practicality, and resources.