Tuesday, October 20, 2009

The World Solar Challenge -- A Long Run Down the Stuart Highway

The World Solar Challenge runs about 3,200 kilometers on Australia's Stuart Highway, north to south, Darwin to Adelaide -- through tropical rainforests, across the savannah country, through barren desert to the fertile coastal regions of the south. U-M's Infinium and its rivals will pass breathtaking natural formations such as the Devil's Marbles (below) in the Northern Outback, through offbeat towns like Alice Springs and Katherine, Woomera and Coober Pedy,  and lands that support cultures rooted 60,000 years in the past. The Stuart is a legacy of World War II, named after explorer John McDouall Stuart, the most famous of all Australia's inland explorers. The Stuart is fully paved --  "sealed," as Australians say -- but it's still a rough haul for all comers.

According to the rules, solar car teams will stop for 30 minutes at various checkpoints along the route. (It's worth noting that for regular passenger cars, fatigue-related crashes are common on the Stuart, so Australia upgraded rest areas to encourage drivers to stop and take the necessary breaks to successfully manage this risk.) Only limited maintenance tasks (no repairs) are allowed during a car's  compulsory stops. In order to select a suitable place for overnight stops alongside the highway, teams can extend their driving period for a maximum of 10 minutes; that extra driving time will be compensated by a starting time delay the next day. Because the Stuart is a public road, the cars have to adhere to the normal traffic regulations. But after midday, when the sun is in the west, it's advantageous to drive on the right side of the highway, provided, of course, there's no traffic coming from the opposite direction. So the drivers tend to take advantage of the Stuart's sunny side and a favorable road camber in order to capture the maximum amount of solar energy -- an infraction that officials seem to ignore.

In the inaugural competition in 1982, 23 teams competed, completing the run down the Stuart at an average speed of 67 kilometers per hour (42 miles per hour). In 2005, the Nuna 3 entry from Delft University of Technology touched speeds in excess of 100 km/hour.  
The average speed has shot up to 103 kph (64 mph). This led to some major regulation changes concerning safety. 

The somewhat eccentric towns along the Stuart are something that solar car teams aren't likely to forget anytime soon. Woomera’s major features are a supermarket, liquor store and library. Pimba’s main attraction is a water tank. At Glendambo, passersby can use an emergency phone and wash their clothes at a bore tap outside the Mobil station -- they can even take a dipper of water from the rain water in tanks, if they ask nicely.  Erldunda, not known for being a friendly town, does have a shower that visitors can use for $4. You'll be reading more about small-town life along the Stuart in the days to come.

The Stuart Highway is an inhospitable scratch down Australia's back -- it tests not just machines but people, as does the World Solar Challenge. So when the U-M Solar Car Team comes home, ask them about the Stuart. You'll probably find that their world view is at least a little different than the one they took with them to Australia.