Competitors in this year’s Bridgestone World Solar Challenge (BWSC) faced blazing sun, looming storms and the harsh Australian outback. The biennial 3000km race from Darwin to Adelaide is designed to test endurance and showcase innovation in sustainable transport.

Among the 34 teams was Team Sonnenwagen Aachen, a group of 44 students from RWTH Aachen University and FH Aachen University, supported by Mercedes-Benz. After their 2023 campaign ended in disqualification just 300km from the finish, redemption was the goal in 2025.

Their new solar car, the Covestro Æthon, was refined through stability testing at the Mercedes-Benz Testing and Technology Centre and the Stuttgart wind tunnel.

“The first highlight of the race was the qualifying, which gave us pole position,” recalls team manager Leonie Brandt.

They set the fastest circuit in Hidden Valley Raceway before an electrical fault early in the race the next day stalled progress.

“We were not getting any solar energy, and for a solar race, that’s kind of a problem,” says the team’s head of driving strategy and optimisation Dennis Eckerdt. The repair cost 20 minutes, enough time for 13 teams to overtake.

Repairs complete, the team rallied. For each overtake, communicators in the V-Class lead car signalled ahead at one point six people were coordinating with six rival teams. The V-Class became the team’s mobile command centre, keeping strategy tight during critical moves.

By the end of day one, Team Sonnenwagen had surged back to fourth place, only 30 minutes off the lead group. “After the repair, everyone was a bit down but overtaking all the cars really cheered everyone up,” says Leonie.

Beyond supporting the team’s solar car Mercedes-Benz Vans played a quiet but essential role throughout the 3,000km journey. The V-Class, used as Team Sonnenwagen’s lead vehicle, doubled as a mobile command centre where communicators coordinated strategy, tracked conditions and relayed crucial updates to the driver.

The V-Class' comfort and space gave the team the ability to work on the move, while its reliability ensured support never faltered.

By day three, milestones were being met, and the team had consolidated their fourth-place position. “For us, we were in a quite comfortable spot,” adds Leonie. “The top three teams overtook each other multiple times in a day, and the section behind us was similar.”

Strong headwinds later put the Æthon’s stability to the test, but the design refinements proved their worth. “It’s much more enjoyable to drive the new car,” says Felix. “You don’t have to hold onto the steering wheel and try to keep it on the road all the time.”

Day five brought torrential rain, heavy traffic and tornado warnings as the race neared its end. Felix, chosen to drive the final stretch, relied on constant updates from Leonie in the V-Class support vehicle.

“After some testing, we figured out that we’d have to be really sensitive to bumps,” says Leonie, “because in the Mercedes, we didn’t really feel them. It was almost too comfortable!”

Despite flooding and slow speeds, the team pressed on. “Sometimes it was like a solar boat,” laughs Felix. “Like a submarine!”

Team Sonnenwagen crossed the finish line in Adelaide in five days, securing fourth place behind teams from the Netherlands and Belgium. “The main aspect this year was getting the car stable and making it to the finish line,” says Leonie. “That was a really big goal, and we achieved it.”