PHOTO: Hans-Peter van Velthoven

ray runner: Blessed with a crystal-clear sky, the Nuna 4 solar car soaks up energy as it drives.

A legion of 38 solar cars gathers in State Square in Darwin, on the northern coast of Australia. The flat, rectangular bodies hug the ground like three-wheeled UFOs, their etherealness accentuated by their motors’ eerie, barely perceptible hum. Anxious racers neurotically swab their perfectly clean solar cells with feather dusters.

Helmeted drivers peer out through polycarbonate bubbles, waiting for their cue to lock down and dash across the continent. The vehicles are odd-looking and yet stately, not at all the giant cockroaches they have been mockingly described as in the past. Better to be a UFO, some are saying, than a cockroach.

The solar racers—a mix of university students and hobbyist-engineers—have converged in this remote tropical city for the ninth World Solar Challenge, the biennial transcontinental race that tests some of the world’s most innovative ideas in energy-efficient transportation on some of the planet’s most punishing terrain. On this humid October morning, ultracompetitive teams are polishing vehicles that easily cost more than US $2 million each, while others tinker with their homegrown labors of love.

At this Panasonic-sponsored event, the foremost eco-race on the planet, there’s tech intrigue and plenty of peculiarity. One team famously delivers its vehicle to each race in suitcases, and another team consists entirely of Japanese hairdressers. The University of Michigan contingent is here, as always, but this year it includes 100 support people, weather balloons, and an unpiloted aerial vehicle. Michigan and another group, Solar Team Twente, from the Netherlands, have each outfitted their vehicle with a system of mirrors that tracks the sun to concentrate light on some of the solar cells. Even in this race, no one’s ever put a solar concentrator on a car before, and its presence on these two has earned the teams cachet in the unofficial jostling for technical one-upmanship. Gossip swirls around Umicore Solar Team, from Group T, an engineering university in Leuven, Belgium, whose Umicar Infinity supposedly uses the most expensive—and powerful—triple-junction gallium-arsenide solar cells this side of low Earth orbit. Solar racers have been eyeing the Belgian vehicle even more warily since yesterday afternoon, when Umicar grabbed pole position in the qualifying heat at a nearby racetrack.

Photo: Hans-Peter van Velthoven

All for One: Members of the Delft University racing team hold up their solar panel to capture the few rays of light creeping over the horizon.