ADELAIDE: There’s a new world record for the fastest solar-powered land vehicle: 88 km/h average speed over one kilometre in a lightweight car that uses about the same power as a toaster.
The vehicle, called Sunswift IVy, was built from scratch in 2009 by students from the University of New South Wales in Sydney. Its large, wing-like surface area picks up maximum sunlight to power its three wheels.
“We’re really on the edge of energy efficiency,” said project manager Daniel Friedman, whose team managed to convert 98% of power from solar panels into kinetic energy. The record run used only 1050 watts of power, similar to that used by a toaster.
Record broken despite cloud threat
The record was broken on January 7, 2011 at the at the HMAS Albatross navy base airstrip in Nowra, New South Wales, with officials from Guinness World Records in attendance.
With near constant cloud cover, the day had less than perfect weather conditions for a solar powered car, but at 10:30am a break in clouds offered the necessary sunlight for the team to make the record of 88 km/h average speed over one kilometre.
The previous world record was 78 km/h, made by General Motors’ Sunracer in 1987. Sunswift went 13% faster using 25% less power.
Efficiency is the key
Solar car designs need to minimise friction and drag. “Once you have an aerodynamic design you have to go from that computer simulation into something sturdy and safe,” said Friedman.
Built with carbon fibre, Sunswift is a tenth the weight of an average car. It usually contains a battery, but this was removed for the world record attempt.
The vehicle features a motor controller – a black box that decides whether power goes to the battery or to the wheels. It also uses regenerative braking. “When we brake we actually charge up the battery,” said Friedman.
Technology impacts on hybrid, electric vehicles
The Sunswift IVy project took 18 months to complete and cost $280,000 plus goods provided by sponsors. It uses silicon solar cells like those found on rooftops, manufactured in 2001 and 2002. Although the gallium arsenide variety used on satellites are more efficient, they are also five times more expensive, he said.
“The way I see it, no one will really own a solar powered vehicle. We see it more like Formula One,” said Friedman in a video of the record breaking attempt. “You’d never buy one, but the technology has already made its way into hybrid and electric vehicles.”
Mike Dennis from the Australian National University was involved in the Aurora solar vehicle research that began in 1980. Over the past 10 years “big strides have been made” in solar powered vehicles, he said.
But he said the real value for solar racing is in “raising awareness of what solar cells can do,” he said. “In any discipline at all there’s a chance to be the best. It’s great for the team and for Australia to have this achievement.”