After a year of dedicated engineering and innovation, the Chalmers Solar Team is set to compete in the Bridgestone World Solar Challenge 2025, taking place August 24–31 across the Australian outback. Recognized as one of the world’s most demanding endurance events for solar-powered vehicles, the race spans 3,000 kilometers — from Darwin in the north to Adelaide in the south — powered solely by the sun. Behind the project is a team of 30 volunteer students from Chalmers University of Technology in Sweden, who have designed, built, and tested the car Arvaker from the ground up. The initiative is considered one of the university’s most ambitious and educational engineering challenges.
"Now we feel a mix of excitement, nerves, and pride. The competition is the culmination of over a year of hard work and dedication," says Tilde Thurfjell Emilsson, Head of Economics for the Chalmers Solar Team and a student in Chalmers' mechanical engineering program.
She is currently in Australia and looking forward to the solar car race.
"There have been many long nights behind this car. It was never a given that we’d make it here. None of us were part of the last race, so we don’t know exactly what to expect, even though we’ve heard a lot from our alumni." Tilde says the Chalmers Solar Team believes Arvaker is the best solar car Chalmers has ever built, which makes them especially eager to finally showcase what both the team and the car are capable of.
From Allsvin to Arvaker – a new car, new challenges
The Chalmers Solar Team has participated in the competition before, but for the 2025 edition, the team has made a significant leap. The cars' names – Arvaker and Allsvin – come from Norse mythology, where the two horses pull the sun chariot Alfrödul across the sky. The new car, Arvaker, is significantly larger than its predecessor Allsvin – partly thanks to new race regulations allowing for bigger solar panel areas. Despite its size, the car is also more aerodynamically efficient, according to the team’s simulations.
"Arvaker is faster, more efficient, and better suited to the changing conditions of the Australian winter," says Tilde Thurfjell Emilsson.
The team brings together a wide range of expertise – in mechanics, electronics, strategy, logistics, and marketing. Several race-specific roles are also in place – such as Battery Officer and Safety Officer, responsible for battery safety and the safety of everyone on the team.
"And of course, we also have our drivers and our team manager," Tilde adds.
Formula 1 is about speed, technology, and human skill. What makes a solar car race different?
"You could argue that speed, technology, and human skill are just as important in the Bridgestone World Solar Challenge. But the main challenge lies in endurance and efficiency," Tilde says.
"The engineers must design a car that not only moves quickly but can handle the unique challenges of the Australian outback – a vast and often unforgiving environment. Another part of the challenge is that a team of nearly 20 people has to travel over 3,000 kilometers together. Organizing this efficiently is a huge part of the race and something that sets it apart from many other motorsport events. The fact that everything is student-led also gives the competition a unique character."
Mentally demanding for the drivers
"For the team, the biggest challenge is making everything work when conditions change rapidly – and being able to adapt."
"For the driver, the main challenge is the monotony. You’re driving long, straight stretches in high heat. Staying focused while the sun is beating down can be mentally exhausting."
To ensure safety, the driver is in constant communication with a support vehicle.
"So even though the driver is alone in the car, they’re never truly alone," says Tilde.
This year, Chalmers' goal is to finish the race for the first time – something not all teams manage.
"On top of that, we want to be the best Swedish team – and we believe we have a real shot at that."
A bit of friendly espionage
Ahead of the race, the Chalmers team has kept a close eye on the competition’s progress. Through social media and team meetups, they’ve gained insights into global developments and innovative solutions.
"It’s something we do continuously. Curiosity drives us to see how other teams solve the same challenges we face."
"We’ve also met and exchanged experiences with several other teams, both from Sweden and abroad. Now that we’re in Australia, we’ve had lunch with teams from Switzerland and Australia, and even visited their workshops to check out their cars. There’s a strong sense of community here – despite being competitors," says Tilde.
The big adventure in the Australian outback
"What’s most exciting is seeing how we actually perform out in the real world," Tilde says.
"To head out into the Australian wilderness and see how well everything works – and how fast we can go under the Australian sun – will be incredibly thrilling." "And of course, the whole experience is an adventure. For many of us, this is the furthest we’ve ever been from Sweden – so it’s exciting to experience a new environment and culture while meeting teams from all over the world."
A message to tomorrow’s vehicle developers
Tilde hopes their work shows that you don’t have to wait until after graduation to build exciting things. "The sustainable solutions of the future might already exist within student projects like ours. A project like this teaches you things that courses can’t, so it’s an incredibly valuable complement to your education. We hope that future vehicle developers dare to invest in students and new ideas."
And if you dare to dream – where will we see solar-powered cars in the future?
"In your garage," Tilde says with a smile. "The possibilities are endless. Even though the type of car we’re building now wouldn’t suit an everyday family, the technology we’re developing could absolutely play a key role in the sustainable transformation of the transportation sector."
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The Bridgestone World Solar Challenge 2025 competition attracts students and engineers from around the world with their self-built solar cars.
