Words and Pictures

with Elizabeth Walton

The World Solar Challenge – 4 Wheels, Greece

Telemetry, sweat, heat and wit

Terra Australis – The Great Southern Land. The continent stretches its arms up to Asia and its toes reach down for Antarctica. In between there’s not much but flies, sand and sun. Every three years the highway – from Darwin in the tropical north, to Adelaide in the chilly south – comes to life with a swarm of solar cars. The teams come from all over the world to test their wits against the odds. They harvest every drop of sunshine, using state of the art technology which photosynthesises pure light into pure energy.

Solar cars rely on highly sophisticated solar cells to convert the sun’s rays into electricity. The cell efficiency is now as high as 24 per cent. But there’s a lot more to racing 3,000 kms on the power of light than just solar cells.

Tactical telemetry allows teams to make strategical decisions, such as when to run on battery power, and when to run on full solar.

Solar cars have the option of using infinite variable gearing to achieve a wide range of speeds to suit different track conditions. Teams weigh these gains with anguish against the down time created by excess friction. Just the vibrations of the road on this brutal Australian track can cause many stress fractures in solar cars.

The Australian outback isn’t exactly the ideal setting for performing repairs. The red soil matches the scorching red sun – as eroded cliff escarpments stare down at the road in disbelief, offering no redemption from the heat.

Two wheel chain driven cars will drive precariously off the road when a tyre blows out. And if the chains are out of line, you’ll keep chewing through them – again increasing the down time.

The solution is a different design – switch to a hub motor, or add more wheels. A three wheel car can travel on one back wheel if necessary, rather than loosing complete control if the only rear tyre blows.

The cars headed out of the desert towards the coastal fringe of South Australia where, over the Bass Strait, it’s only a gale’s blow across to the Antarctic. The weather was blue in sympathy. It was cold, drizzly, and a whole continent away from the tropics of Darwin – which is closer to Singapore than it is to any other Australian capital city. The teams pleaded ‘rain, rain, go away,’ as they stumbled one by one over the finish line, each exacting a heroic effort, a team victory in the race to develop alternatives to limited fossil fuels. Honda arrived in record time, finishing the 3,010 km race in less than 34 driving hours. The car whirred silently across the finish line through roars from an enthusiastic crowd.

For many teams, the odds proved too much. High schools, universities and professional teams alike withdrew in despair. Some spent the remainder of the race checking in on other teams, lending ideas, muscle and spare parts. The terror of the track didn’t prove too much – they’ll be back. As the sun set on the fourth World Solar Challenge, every team was victorious. For as long as the sun still shines, there will always be a need for solar racing.

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