Team Alpha Centauri from ETH Zurich kicks off the World Solar Challenge 2023 across the outback with its Aletsch solar racer

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The Tour de Sol, held in Switzerland in 1985, was the world’s first solar race. This competition is considered the forerunner of the World Solar Challenge, arguably the most environmentally friendly car race in the world and a playground for inventors and students, held every two years in Australia since 1987. Participating race vehicles travel 3,000 kilometers across the Australian desert, running solely on solar energy.

The announcement for the 2023 Challenge, which kicks off in Darwin this Sunday and runs from the outback to Adelaide for around five days, is clear: Once teams start, they must become self-sufficient with solar power in one phase. race cars and run solely on the power of the sun. Complete the prescribed marathon route as quickly as possible. There are nine mandatory checkpoints to pass along the way, where crews are only allowed to carry out the most basic maintenance tasks, such as checking tire pressure or cleaning the vehicle. The route starts every day after sunrise and continues until exactly 5 pm. So, it’s time for all participants, wherever they are, to set up camp for the night.

Goal: To be in the top 10

For the first time in the World Solar Challenge’s more than 35-year history, Alpha Centauri, a team from ETH Zurich, is also participating. Like their fellow students, who recently set a new acceleration world record with their electric racer Mythen, the Alpha Centauri team built their solar-powered racer Aletsch at the disused military airfield in Dübendorf ZH. “Initially a year ago this was just a very small focus project, but more and more freelancers were added day by day and invested a lot of free time and knowledge in creating our racer,” says ETH Zurich student and team member Alexander Ebnöther. manager. He has no illusions about participating in the World Solar Challenge for the first time. “As newcomers, we start with the motto, ‘To finish first, you have to finish first.'” There are already some expectations in the Swiss team. “It should be possible to get into the top 10,” team spokesman Suno Diekmann officially said. And secretly dreams of a place on the podium.

In developing their solar-powered racing car, ETH students built on successful vehicles from previous challenges and also actively exchanged ideas with other teams. “We wanted to develop the best possible design and optimize it with our own ideas,” explains Suno Diekmann. The result is a racing car in the so-called bullet design. In other words, it is a tricycle with a tapered front and two wheels in the front and one in the back. “So it floats like a ball in the air,” explains Diekmann. He explains just this much about the drive technology: “In principle, the four square meter photovoltaic panel on the roof of the vehicle captures solar energy and stores it in our 20-kilogram battery. This then feeds the electric motor in the rear wheel.”

Weather resistance like exterior mirror

Since only solar energy can be used and no other energy source, the race vehicle needs to be very aerodynamic and lightweight, but still robust enough to endure harsh desert adventures with cockpit temperatures above 50 degrees. The weight of the ETH racer is only 260 kilograms with the driver, but to be fair the pilot needs to weigh at least 80 kilograms (there is additional weight if it is lighter). Dieckmann’s comparison reveals just how efficient the ETH solar racer is: “The air resistance of our race car is comparable to that of a car’s side mirror.”

In the competition last held in 2019 due to Corona, the average speed of the winning Belgian team was 86.6 km/h. The best solar cars can easily reach speeds in excess of 100 km/h. “But the biggest challenge is to maintain this fast pace for several hours,” says Diekmann. “It is possible to break a new speed record this year. However, we aim for an average speed of around 80 km/h.” This was enough for third place in 2019.

Source: Blick