Over its 30+ year history, the Bridgestone World Solar Challenge has become the most well-known solar-powered car racing event on the globe. Every two years, the challenge brings students and innovators, from all over the world, to Australia for a chance to compete and to push the limits of solar cars.
In just a few months, the 2019 Bridgestone World Solar Challenge will kick off, and the Netherlands and Belgium look to be well-represented, sending 5 out of the 48 teams to compete in the Down Under. The challenge consists of a 3,000-km road race through the harsh Australian Outback, with teams participating in one of three classes.
The adventure class is for groups wishing to participate, but not compete. The challenger class is intended for aerodynamic, single-seat vehicles built for sustained endurance and maximum energy efficiency. Finally, the cruiser class consists of solar cars designed not just for the speed, but for practicality and with distance to the market in mind.
One by one, the solar teams of the technical universities of Eindhoven and Twente, the Catholic University of Leuven (KU Leuven, Belgium) and a new collaborative, representing the North of the Netherlands have begun unveiling their cars in anticipation of the October competition.
The first car revealed was the Red E from Solar Team Twente. The shell consists of a layer of foam sandwiched between two layers of carbon and features a 2.64 square meter GaAs solar panel to harness energy. Solar Team Twente is also touting the use of a suspension based on the model currently used in Formula E racing, as well as its self-developed engine that is embedded within the right rear wheel and is powered by its in-house motor control unit. This challenger class vehicle is the smallest ever for the Twente team, shaving a full 1.5 square meters off its 2017 model. “The air resistance of the finished car is comparable to a small can of coke,” claimed team aerodynamicist, Mariska Bos.
The next group to unveil was the Agoria Solar Team from the KU Leuven. After taking third place in the 2017 World Solar Challenge and winning an extreme race last year in Chile, the Belgian solar team has high hopes for its challenger class entry, Bluepoint. For the first time, the Agoria team has developed its own solar panel, measuring 2.6 square meters. In addition to the self-made solar cells, the Belgians spent more than six months working on body design and aerodynamics – producing the most aerodynamic car in Belgium. “In order to avoid unnecessary waste of space, the car is literally tailored to my size. My hips and shoulders fit in perfectly,” says Inge Habets, Agoria team pilot. With this sleeker design and solar upgrade, the team claims it can achieve a 600 km driving range and the capability of reaching a 130 kmh top speed.
The Top Dutch Solar Racing team representing the North of the Netherlands will also be heading to the bush to participate in the 2019 challenge. While many of their competitors are coming from some of the more competition-experienced technical universities of the Netherlands, the same cannot be said for them. The Groningen-based newcomers are a collaborative from the Hanze University of Applied Sciences, University of Groningen and the Noorderpoort vocational training center.
The final regional participant in the cruiser class is perennial favorites, the Vattenfall Solar Team. The TU Delft team has been crowned champions of the challenger class for a record seven times. This year’s submission, the NunaX, is the tenth car made by the Vattenfall team and is said to be the most efficient of all its predecessors in the Nuna family. The NunaX is the smallest and lightest submission ever, weighing in at a slim, 133 kilograms. To cut down on weight, the Delft students got rid of the layer of glass that was previously used to protect the solar panels and instead opted to apply their own protective coating. The car uses gallium-based solar cells and is fitted with a small, solar-cell covered wing that’s aimed at capturing both the wind and any additional solar energy.
“During the previous race, we discovered that the small Nuna9 benefited enormously from the strong side-wind that we always have in southern Australia. It’s a little like the way a sailboat is driven by the wind,” commented team technical manager, Bruno Martens. “For this car, we’re using both solar energy and a little bit of wind energy.”
Three-time defending cruiser-class champions, Solar Team Eindhoven (STE), also revealed the next generation of its Stella family of cars: Stella Era. Looking to build on previous success, students from the Eindhoven University of Technology put a real emphasis on efficiency. Their goal was to increase the energy yield of the five-square-meter solar panel, while also reducing power consumption.
To achieve this, the team renewed its focus on the powertrain as a whole – from the battery management system to the electric motors. The battery is said to be able to travel four times as far with a battery pack compared to those used in an average electric family car, while the engines for the car are self-designed in-wheel motors. According to the solar team, these motors can decrease power usage and can reach an efficiency of 98.5 percent. With these enhancements, STE claims that with ideal conditions and when optimized for efficiency, their car can drive up to 1,800 km on a single charge.
Aside from these performance upgrades, the Stella Era also offers some new practical and convenience features. For instance, designers have implemented an autonomous driving feature where the car can search for a parking spot with optimal sun and move itself in order to charge more efficiently. Another new feature is that the Stella Era can be used as a mobile charging station, with the ability to share stored energy with other electric vehicles.
The starting gun of the Bridgestone World Solar Challenge fires at 8:30am on 13 October in the Northern Territory’s coastal city of Darwin. The teams will then spend a week spanning the more than 3,000 km course before crossing the checkered line in the South Australia’s city of Adelaide on 20 October.
Main photo: Geert Vanden Wijngaert