13/06/2025

Racing the Sun: Engineering the World’s Most Successful Solar Racing Team

By Alex Edwards

What does it take to build a car capable of crossing a continent on nothing but solar power? For the Brunel Solar Team, it’s a combination of deep engineering talent, relentless motivation, and an ability to adapt under pressure. As the world’s most decorated solar racing team prepares for the 2025 Bridgestone World Solar Challenge, I sat down with two of its members, Merijn Kroon, Partnerships, and Lucas de Jong, Mechanical Engineer, to explore the innovation behind their latest vehicle, their collaboration with Protolabs, and what it really takes to chase the sun across the Australian outback. 


Building More Than a Car 

Each year, a fresh team of students from TU Delft in the Netherlands puts their degrees on hold to focus full-time on one ambitious goal: designing, building, and racing a solar-powered car across 3,000 kilometres of Australian wilderness. The team draws from a broad mix of disciplines—mechanical engineering, electrical engineering, architecture, aerospace, industrial design, and more. As Merijn explains, “There’s no course at university on building solar cars. What really matters is motivation and the willingness to learn fast.” 

Each team is carefully selected by the outgoing group, with a focus on complementary skills. “It’s not just about technical know-how,” adds Lucas. “It’s about creating a team that communicates well, adapts quickly, and supports each other.” 



The 2025 Challenge: A Race Against Time and Nature 

This year’s race introduces fresh engineering challenges. Firstly, it’s scheduled two months earlier than usual, in August rather than October—right in the middle of the Australian winter. That means fewer daylight hours and lower solar intensity, directly impacting the energy available to the car. 

Compounding the challenge is a major rules shake-up. “We’re now allowed to use six square metres of solar panels—up from four,” says Merijn. “But that doesn’t mean we can just scale everything up. A bigger solar array introduces aerodynamic and structural complications, and all of this with two months less development time.” 

To make matters more interesting, the allowable battery capacity has been slashed to one-third of previous years. That makes smart energy management not just useful, but essential. 

“We can’t just rely on speed,” Lucas says. “Strategy becomes everything. From wind and weather to incline and sunlight patterns, the winning team will be the one that adapts fastest.” 


Precision Partnerships: Working with Protolabs 

To build a car this innovative on such a tight timeline, reliable manufacturing support is critical. That’s where Protolabs comes in. 

“We’re always looking for partners who share our values around sustainable innovation,” Merijn says. “With Protolabs, the enthusiasm and willingness to collaborate stood out from the start. Their speed and precision made them a natural fit.” 

Protolabs supplied key CNC-machined components including the brake pedal bracket—crucial for safety—and the front suspension damper brackets. “These are high-load, safety-critical parts that must be lightweight but durable,” explains Lucas. “We used aerospace-grade aluminium and relied on finite element analysis to validate designs before manufacture. Protolabs was able to deliver complex, high-tolerance parts fast—exactly what we needed.” 

Thanks to tight coordination, parts were delivered and mounted on the car in time for early testing. With testing complete, the team could draw breath and focus on less time-sensitive parts, including spares. Additional components were later 3D printed via Protolabs Network, at longer, more cost-effective lead times, adding valuable flexibility to the manufacturing process. By partnering with Protolabs, the team could accelerate the manufacturing process when the pace demanded it, and cruise when efficiency was in pole position. 



Engineering a Safer Solar Future 

While the car is designed for maximum efficiency and lightness, safety remains paramount. “We’ve got an impact-resistant occupant cell, a balance-bar braking system, and new this year—a roll bar similar to Formula One’s Halo structure,” says Merijn. “The entire system is built to comply with strict safety checks during scrutineering in Australia.” 

Even with the lightweight design, the car remains incredibly stable. “The aerodynamic drag increases massively as you go faster, so our cruise speed is around 90 km/h. It’s all about efficiency—not max speed,” says Lucas. In fact, the team’s 2005 car still holds the solar racing speed record, clocking an average of 131 km/h over 3,000 km. 

The race itself takes place on public roads, with speed limits and real-world weather to contend with. “You only have one shot,” says Merijn. “Anything can go wrong—weather, mechanical, even wildlife. We heard stories of teams waking up with snakes in their tents.” 


More Than a Race 

While solar racing isn’t (yet) the future of commercial transportation, it has a vital role to play. “We don’t expect everyone to drive a solar-powered car tomorrow,” Lucas admits. “But solar as a range-extending technology? Absolutely. Some manufacturers are already exploring that.” 

Ultimately, the race is a showcase—a proof of what’s possible. “If 18 students can build a car that crosses a continent using nothing but sunlight, what’s stopping the rest of the world from embracing renewable energy?” Merijn asks. 


Lessons Beyond the Workshop 

Beyond the engineering challenge, both Merijn and Lucas agree the experience has shaped them personally. “The biggest lesson is how to be part of a high-performing team,” says Lucas. “You learn how to work under pressure, communicate effectively, and put trust in each other.” 

The team is even coached by a former Olympic champion from the Dutch national hockey team—underscoring the importance they place on performance culture as much as technical expertise. 


Follow the Race 

Brunel Solar Team’s 2025 car was revealed on June 10, with the World Solar Challenge taking place in August. Follow their journey on social media for behind-the-scenes footage, live updates, and insights into the future of solar mobility.