Nuna4
The year of Nuna4, the rules of the World Solar Challenge were seriously adjusted compared to its predecessors. Nevertheless, the car managed to finish the race in 33 hours and 17 minutes. Hereby she had an average speed of 90 km / h and Nuna4 won the World Solar Challenge 2007.
However, a top speed of 142 kilometers per hour was achieved during the race. The big difference in racing time compared to its predecessor was a change in the rules of the race. The solar panel surface area was reduced from 9 square meters to 6 square meters, so that less energy income was available. The driver's position was also tested against stricter rules, so that the canopy (the driver's roof) became much larger. This yielded more air resistance and resulted in a lower average speed. By dealing well with these new rules, a winning solar car from TU Delft still appeared at the finish of the World Solar Challenge 2007.