Turning the energy of the sun into motion is an idea that long has captured the human imagination. Of course, the sails on boats capture the form of solar energy known as wind. But to make a car move on sunlight requires a wide, flat surface on which photovoltaic (PV) panels can work their magic. As a result, solar cars are as striking in appearance as the energy efficiency they can achieve.

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At the former Humberstone saltpeter works in northern Chile this fall, 11 teams from five countries gathered with an array of solar-powered contraptions on wheels. Their mission was to compete in a historic race of vehicles powered by nothing but two of the oldest energy sources known to man: muscle power and the sun.

The race covered 620 miles (1,060 kilometers) over three days in the Atacama Desert, known as the driest desert in the world.

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The route snaked from Humberstone—a ghost town and UNESCO World Heritage Site—through the fast-growing coastal city Antofagasta and inland Calama, a staging center for one of the world's largest open pit copper mines, before returning north to Pozo Almonte near Humberstone. Dubbed the Atacama Solar Challenge, the event made history as the first international solar race ever hosted in Latin America.

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Here, during stage two of the Atacama race, the driver for team Antakari is seen rolling through Antofagasta. Made up of students from Universidad de la Serena and Illapel Polytechnic as well as engineers from the Los Pelambres copper mine, Antakari won first place in the all-solar category. The car finished the race with an average speed of 75 kilometers per hour (46.6 miles per hour).
—Josie Garthwaite

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.

Pictures: Cars Capture Solar Energy in Chilean Desert

The need for a wide, flat surface to harvest sunlight gives an otherworldly look to solar cars racing the Atacama Desert of Chile.