Delft Solar Team has secured second place in the American Solar Challenge after eight intensive days and more than 4,000 kilometres of racing across the United States.

The TU Delft student team was competing in the American solar car race for the first time. Driving Nuna 13S, the students finished just behind Belgium’s Innoptus Solar Team after a closely fought and highly strategic race.

The two teams remained evenly matched throughout much of the competition. The seventh day proved decisive, when both teams completed their final additional loops to add as many kilometres as possible to their overall scores.

After the last loops, Delft Solar Team remained behind Innoptus and began the final day in second place, with another 210 kilometres to travel along the main route towards Amarillo.

Despite careful strategy, efficient solar panels and close management of Nuna 13S’s available energy, the Delft team was unable to close the remaining gap.

“It was incredibly close,” said team leader Guus van der Donk. “That makes missing out on the win particularly disappointing. At the same time, we gave everything and fought until the end. Finishing second during our American debut is an achievement we are extremely proud of.”

A solar race without much sun

One of the biggest challenges was something a solar-powered team would rather avoid: a lack of sunshine.

The sun barely appeared during the week, meaning Nuna 13S had to cover large parts of the route relying on its battery. At other times, heavy rain reduced visibility.

At the same time, temperatures climbed above 40 degrees Celsius and humidity reached as high as 94 per cent.

Electrical engineer Job Valkenburg recalled an additional problem inside the car on the first day.

“Before the first race day, we had forgotten to drill a hole in the bottom of the cockpit. Normally the sweat drains away through it, but now all the moisture stayed in the car. Afterwards, we literally had to wipe the sweat out of the car with cloths.”

The heat also affected the drivers physically.

“At some points, it became so hot that I felt unwell,” said driver Bas van der Meer. “We had to manage our drivers much more tactically. We continually adapted our strategy so that we could keep driving for as long as possible without compromising safety or performance.”

Strict rules on American roads

The American Solar Challenge also presented the Delft students with a very different racing environment from competitions they had previously experienced in Australia.

The team also has a long history of racing in Australia. Our sister publication Dutch Australian covered Nuna 13’s victory in the 2025 World Solar Challenge.

Strict penalties could be imposed for traffic violations, technical errors or unsporting behaviour. Each penalty resulted in kilometres being deducted from a team’s total distance, meaning a missed stop sign or small mistake could immediately affect the rankings.

“We had never before experienced such strict penalties during a race,” said Folkert Straus, former chief engineer of Nuna 12.

“In Australia, we drove for kilometres through the empty outback. Here, we were constantly driving through residential areas, with traffic lights, stop signs and low speed limits. Nuna was technically in excellent condition, but after days of racing under difficult circumstances, we also make human mistakes.”

An unforgettable first American race

Alongside the technical and physical challenges, the students also experienced considerable support from people along the route.

“We experienced an enormous amount of hospitality from local people here,” said race manager Wietske Overdijkink. “We were encouraged along the route, people offered us places to stay and clearly shared in the experience with us. That made this race unforgettable.”

Delft Solar Team is a TU Delft student team that has been designing and building solar cars since 2001 and competing at the highest international level.

With twelve world titles, the team has built an international reputation for innovation, sustainability and teamwork. Its first participation in the American Solar Challenge has now added a silver finish to that history.

Source: Press release from Delft Solar Team. Translated from Dutch and edited by Delft Online.