Twenty-nine cars from 17 countries are set to leave Darwin in the 2015 World Solar Challenge, racing 3000 kilometres across the country to Adelaide using just the power of the sun.
Defending champions, the Dutch Nuon Solar Team, are once again favoured to be at the head of affairs with the Nuna8 car featuring a new design with improved aerodynamics.
They will be challenged by other regular contenders including the US team from the University of Michigan and the team from Tokai University in Japan with their car, Tokai Challenge.
Only minutes separated Nuon and second-placed Tokai in the last challenge in 2013.
Nuon spokesman Michel van Baal says the team have prepared well, right down to working out the best lanes to take through city traffic.
"Although traffic in Australia is extremely light compared to the Netherlands, around cities it can be busy," Mr van Baal said.
"Precious minutes can be lost by making the wrong decisions."
Another key aspect for teams has been securing supplies for the trip south, especially distilled water used to keep solar cells clean and cool without leaving a layer of salt on the solar array.
Three Australian teams will start from Darwin's State Square on Sunday: Clenergy TeamArrow and teams from Western Sydney University and the University of Adelaide.
Scrutineering took place in Darwin last week to ensure all cars qualify for road registration and meet safety standards.
Five teams failed on their first presentation, including Tokai University.
The first cars in the Challenger Class are expected to reach Adelaide mid-week.
