Racing a distance of 3,000 kilometers under the blaring Australian sun for little more than pride sounds like a crazy idea only an Aussie could come up with.

Racing a distance of 3,000 kilometers under the blaring Australian sun for little more than pride sounds like a crazy idea only an Aussie could come up with.  But when that race is meant to demonstrate advances in solar power technology, it suddenly sounds a little less crazy.

The World Solar Challenge kicks off this Sunday, October 21, with teams from universities, research institutes, utility companies, automakers, and even families all converging from around the world on Darwin, Australia.  WSC started 20 years ago, with races every three years.  Now, races occur every other year.  This will be the eighth World Solar Challenge.

The rules are pretty simple.  The race starts in the northern territory, with the finish line 3,021 kilometers away in the South Australian city of Adelaide.  Teams must have a minimum of two drivers, but no more than four, with weight from the driver and ballast equaling 80 kg.  Each day of racing begins at 8am and finishes at 5pm, with drivers getting a 10-minute grace period to find a place to park at the end of the night.  30-minute maintenance checkpoints are all over the route, but general repairs are not allowed.

These solar cars are allowed to have a 5kWh battery fully charged at the start of the race, but the battery may not be replaced except if a breakdown occurs.  Should this happen, teams will be assessed a penalty.  Brakes must be able to decelerate at a minimum of 3.8 m/s2.  There are only broad outer dimension restrictions, so these solar cars may take many unusual shapes.

For the 2007 race, organizers decided to put restrictions in place to make cars a little more situated for real life.  The driver must be able to get in and out of the car on his own, must sit upright in the car, and must use a steering wheel to drive the car.  Only six square meters of solar collectors are allowed at maximum. 

Although the rules of the road must be followed, many drivers try to get an edge by driving on whichever side of the highway is getting the most sun.  Speed limits of 130 km/h in some northern areas and 110 km/h in some southern areas must be adhrered to.

There will be a "Greenfleet" class of racing cars this year, showing off their fuel efficiency.  Some of these participants include the Smart fortwo, Audi A3 Sportback 1.9 TDI, and the Saab 9-5 BioPower.  General Motors, which has particpated in the race since its 1987 inception, will have involvement on four of the cars this year.

The Dutch team behind the Nuna solar car will be looking to defend their title this year.  The team won three races in-a-row under the sponsorship of the Delft University of Technology.  Now, with electric company Nuon banking them, they will be looking to defend their crown.

Sunday is going to be hot on race day, with a high of 93 degrees Fahrenheit (34 degrees Celsius) and partly cloudy skies expected.  The race wraps up on October 28.  You can follow the World Solar Challenge live at the WSC web site.

Gallery: World Solar Challenge Kicks Off Sunday