Four time World Solar Challenge winner unveils new car - the Nuna5
By Paul Evans
July 14, 2009
The team that won the World Solar Challenge for the last four years running has unveiled its latest solar racer. Like its predecessor, the Nuna5 from Delft University's Nuon Solar Team is covered with six square meters of solar panels but is 30kg lighter at a super low 160kg excluding driver.
The solar panels are made up of 2120x Gallium Arsenide triple joint cells with 34% efficiency. These drive an Australian CSIRO developed Axial Flux BLDC in wheel motor that produces 50 Nm of torque at 97% peak efficiency.
When the solar cells are producing more power than is required to drive the motor the excess is stored in a 25kg lithium polymer battery pack.
The aerodynamic load is approx 1/12th that of a normal road car while the rolling resistance is 1/10th.
The Australian based solar race is probably the toughest in the world. It covers 3000km of mostly desert road between Darwin and Adelaide and teams must set up camp on the side of the road each night where their car stops as the sun goes down. This year vehicles are required to have treaded tires, which create more rolling resistance and makes it more difficult to achieve the incredible level of efficiency required to win the race.