“The Stella Era marks the beginning of a new era wherein the car no is no longer just focused only on itself,” is how Mick van der Spoel, project manager of the Solar Team Eindhoven, introduced the new name of the fourth solar car from Eindhoven. The Stella Era also refers to the team as ‘a battery on wheels’. The sharing of energy is indeed one of the most important new functions of the solar car. In October, the student team will try to defend its title during the World Solar Challenge 2019.
Energy is for sharing
There are three connections at the rear of the car, one for charging the car at a charging station, one for charging other electric vehicles, and a normal socket so that you can make coffee on the campsite for instance. Using the proprietary Stella App, the Stella Era can be found on a map on which you will also see charging stations. This allows you to look for another solar car so that you can recharge your own electric car. To make sure that you always have enough energy left to drive home, the Era takes the weather conditions and the appointments in your schedule into account.
Of course, at the moment the car needs to be in the sun in order to charge as efficiently as possible and generally speaking, you are not going to be moving your car a couple of times during your workday. The student team has come up with a solution for this as well: the car does this by itself! Thanks to a collaboration with TomTom, among others, the Era can determine where the most sun is at any given time in the parking lot. The Era is then able to drive itself to the new location thanks to sensors and radar located around the car. In addition, the car keeps to the perimeter of the parking lot where it is located. Marije Sesink, PR-manager of Solar Team Eindhoven, explains the features: “We designed this car not only for the Australian outback, but also for cities where there is plenty of shade.”
Like its predecessors in the Stella family, the Era is all about efficiency. This is reflected in the teardrop shape of the car, but also in the cameras that are used instead of side mirrors. Aside from that, the weight has been kept as low as possible and the transmission has been made as efficient as possible. Where in previous years the transmission was still being purchased from other manufacturers, the team has now redesigned it from the ground up. “We did this on the basis of a publication by someone at the university,” says Van der Spoel. “A normal company takes five years, whereas we only have nine months for this.” By using this self-designed drivetrain, the engine efficiency in theory is at 98.5%. In comparison: the efficiency of a regular petrol engine is about 25% and the engines of in the first Stella were just over 90%. “The last few percent seems small, but this is a major step,” Van der Spoel explains.
Collaboration with Audi
In order to build the best car possible as a student team, Solar Team Eindhoven has collaborated a lot with various companies. In addition to partners such as TomTom and NXP, who are making autonomous driving possible, the team also has a partnership now with a leading car manufacturer: Audi. The cameras that replace the side mirrors come from the Audi E-tron. “Regular car manufacturers are also increasingly recognizing the need for efficiency, and the replacement of side mirrors is a good example of this,” says Van der Spoel. “We are extremely pleased that we have taken the first step by working with a car manufacturer. At the end of the day, we also want to see our technology actually on the road.
On the way to Adelaide
Before the car travels to Australia, the team wants to again apply for a license plate from the RDW (the Netherlands Vehicle Authority), just as did with the Stella Vie. There is still a lot of testing and development to be done before all the plans become reality. But the goal is clear: Win. Sessink: “The rules of the World Solar Challenge have changed a lot, so now you can only charge twice. Also, now there is more focus on the functionality of the car. Whereas at first 70% of the final score was based on the car’s efficiency while only 30% was on comfort, that has now been leveled out.” This is why Solar Team Eindhoven wants to impress the jury with the first family solar car that has autonomous features which can also be used as a charging station.