The [Panasonic World Solar] Challenge is the world's premier long-distance race for solar-powered vehicles, with competitors traveling 3000 kms [1,800 miles] along the Stuart Highway from Darwin in the far north of Australia to Adelaide in the south in cars powered solely by sunlight. In the process they ... send out a strong environmental message, pushing forward the boundaries of green technology and promoting the benefits of solar power as an alternative energy source. It's a great adventure," the race director Chris Selwood told CNN, "One that allows the bright young people of the globe to come up with creative solutions to the problem of sustainable transport, while at the same time drawing attention to the importance of lightening the environmental footprint of our personal transport needs." First run in 1987, the race was the brainchild of Danish adventurer and environmental campaigner Hans Thostrup, who in 1982 designed and built "Quiet Achiever," the world's first ever solar-powered car. The inaugural competition featured 23 teams, with the winning vehicle -- the General Motors-sponsored Sunraycer -- completing the distance at an average speed of 67 kilometers per hour (42 miles per hour). The average speed has shot up to 103 kph (64 mph) ... while the competition has expanded to incorporate several different classes of vehicle: the Challenge and Adventure Classes for exclusively solar cars, and the Greenfleet Technology Class for other types of environmentally friendly, low-emission vehicles.