Thirty-seven teams from 20 nations have started racing in the Veolia World Solar Challenge from Darwin to Adelaide.
There were last-minute fears that three teams slated to begin the race - one each from India, Germany and Korea - would miss the start after they struck trouble.
Ultimately all vehicles got away from Darwin's State Square on Sunday, with Korea's "Green Maniac" car starting about an hour after the race favourite, Solar Team Twente from the Netherlands.
The teams are aiming to travel all the way to Adelaide, more than 3000 kilometres away, using vehicles powered only by energy from the sun.
Event director Chris Selwood told AAP he was delighted by the start, even though he predicted some teams would probably not make it all the way to Adelaide without a little help.