The Vattenfall Solar Team presents its new solar racing vehicle: the NunaX. It is the tenth vehicle the team is developing. The team hopes to win the world title for the eighth time with the NunaX during the Bridgestone World Solar Challenge in Australia.
The Bridgestone World Solar Challenge is a 3,000-kilometre multi-day race in which participating teams travel across the outback of Australia. The race is exclusively open to solar racing cars. Teams from all over the world take part in the race and try to cross the finish line first.
Vattenfall Solar Team
The Vattenfall Solar Team managed to win the Australian race seven times before. In addition, the team also went on to win three times during the South African Sasol Solar Challenge. In the upcoming edition of the Bridgestone World Solar Challenge, the team will compete with the NunaX. The vehicle was built by the team members of the Vattenfall Solar Team, who all set aside their studies for a period of at least 1.5 years to participate in the Bridgestone World Solar Challenge.
The team worked for over a year on the NunaX, which was developed at Polymer Science Park in Zwolle. The reason for choosing this location was that Aliancys, one of the team's partners, is located at this park. Among other things, Aliancys supplies high-quality resins and carbon fibres for the production of NunaX's exterior and load-bearing structure.
At the start of the development, Zwolle Mayor Meijer said, "I am proud that you are showing the whole world that it is important to be economical with our earth. To use the energy sources we have, such as the sun, as well as possible. Showing these possibilities also inspires other people to get involved. I wish you the best of luck with the construction of NunaX!"
Smart gadgets
During development, the focus was on smart gadgets that can make a difference during the race. Technical manager Bruno Martens explains, "The rules around solar racing have barely changed in recent years. Whereas cars could still be very different in the first races, you notice that teams are copying each other and the cars are starting to look more and more alike. So it comes down to innovation more than ever: the smart gadgets make the difference."
An example of one such gadget is a clever design that allows the NunaX to take advantage of the wind to create extra speed. "During the previous race, we discovered that the little Nuna9 benefited considerably from the strong crosswinds we always have in the south of Australia. A bit like how a sailboat sails on the wind. This time, we specifically took this into account in the design. The canopy and wheel covers are shaped to give the car a boost, so to speak, in side winds. So with this car, we are not only using solar energy, but also a bit of wind energy," Martens explains.
Lighter, smaller and more efficient
In addition, the vehicle is lighter, smaller and more efficient than its predecessor. The NunaX weighs 133 kg. This is lighter than any other vehicle that has ever competed in the solar race before. To save weight, every part of the car has been redesigned. Different raw materials were also used in some cases, while material was shaved off in other parts.
The NunaX features a solar panel made of gallium solar cells, which have long been used in aerospace. These cells are more efficient than silicon cells placed on homes. The solar panel has also been modified to save weight. For instance, the standard layer of glass that normally protects the cells has been removed and replaced by a proprietary protective coating, which weighs less. This coating also contains prisms that ensure that sunlight always falls perpendicular to the solar cell, optimising the yield. A small wing on the vehicle ensures that the panels catch as much sun as possible, which helps optimise yield.
The team will test the NunaX over the coming period in preparation for the race, with the students receiving guidance from former hockey coach Marc Lammers, among others. The first tests will take place in the Netherlands. In August, the team and the NunaX will leave for Australia for on-site testing and preparation.
Author: Wouter Hoeffnagel
