Photos, From toP: Umicore Solar Team; University of Michigan Solar Car Team; Aurora Vehicle Association

League of Their Own: : Umicar Infinity [left] had top‑of-the-line gallium-arsenide solar cells. The University of Michigan’s Continuum [top right] sported a solar concentrator and a host of cooling fans to protect the car’s interior. In spite of its much cheaper silicon array, Aurora 101 [bottom right] came in third.

But it is the legacy of the Nuon Solar Team, from the Delft University of Technology in the Netherlands, that dominates the prerace chatter. Its Nuna cars have won the last three races, going back to 2001. On the other hand, no member of this year’s crew, other than its ex-astronaut advisor, Wubbo Ockels, has ever built a car before. And this past week hasn’t been kind to Nuna 4’s harried engineers, who have battled a temperamental motor controller and short-circuiting solar cells. It didn’t help when Ockels announced that no previous Nuna had faced so many prerace problems.

Standing there as spectators mill around the parked solar cars, Ivo Hagemans, of the Nuna team, notes: “Everyone says, you’ve already won three times, you have nothing to worry about. Well, no, no, I haven’t. Other people have. I have not.” He surveys the car moodily, his hands shoved in his pockets.

The rules are simple [see sidebar, "World Solar Challenge Race"]. Race across 3000 kilometers of the outback, driving from 8 a.m. to 5 p.m., until you get to Adelaide, on the southern coast. Your car’s only power source is a 6-square-meter solar array, which under bright sun puts out less than 2 kilowatts. If your idea of an efficient vehicle is a Toyota Prius, you’ve got to wrap your mind around an entirely different level of energy parsimony. Solar racers like to say that their cars run on as much energy as a hair dryer. By the time the winning car gets to Adelaide, it will have covered those 3000 km using roughly the same energy that an ordinary car gets by burning 7 liters of gasoline. The best cars travel about 90 km/h, though they are capable of going faster. “It’s performance racing,” says Michael Garland, a British university student freelancing as a member of Melbourne’s Aurora Vehicle Association team, another perennial contender. “It may be quirky and weird, but it’s top-notch engineering.”