Four-time World Solar Challenge winner unveils new car

The World Solar Challenge is a grueling car race that runs across more than 3000km of Australian outback, spanning the entire breadth of the continent from Darwin to Adelaide. But the real challenge of this race, which is rather obvious from the name, is that all the competing cars must be completely solar-powered. The objective of this race is to promote research on solar-powered cars and teams from various enterprises and universities participate in it for their quest to better alternative power source technology for automobiles.

For the last four outings of the World Solar Challenge, the team from the Delft University of Technology in Netherlands has been taking home the top prize with their Nuna solar-powered racer. Now, the Delft University's Nuon Solar team has unveiled its latest contender for the 2009 challenge, the Nuna5. Like its predecessor, the Nuna5 is covered by six square meters of solar panels, but now, thanks to advancements in technology, weighs in 30kg less, a total of 160kg excluding the driver, than the previous car.

The solar panels which consist of 2120 separate Gallium Arsenide triple joint cells now operate with 34-percent efficiency, meaning that they can convert a third of the solar energy incident on them into electricity. That might seem like a small number, but it is a huge improvement over the 26-percent efficiency from the cells of the Nuna4. The cells drive an Australian CSIRO developed Axial Flux BLDC in-wheel electric motor that produces 50 Nm of torque at 97-percent peak efficiency. When the solar cells are producing more power than is required to drive the motor the excess is stored in a lithium polymer battery pack.

Other achievements on the Nuna5 include the regenerative braking system similar to KERS from F1, a maximum speed of well over 140km/h and an aerodynamic load that is approximately 1/12th that of a normal road car while rolling resistance that is 1/10th. With its arsenal full of technology, the Nuna5 will be the spearhead of the Nuon Solar Team's attempt to claim their fifth consecutive win on the World Solar Challenge, which will start on 25th of October this year.