With the help of ECMWF's weather predictions, Solar Team Twente from the Netherlands finished second out of fourteen during the Sasol Solar Challenge in South Africa in September 2024. This is a prestigious event, in which student teams from all over the world compete with their self-built solar cars, which are solely powered by the energy of the sun.
During the eight-day challenge, the teams try to cover as much distance as possible by completing additional loops on the route whilst driving from Johannesburg to Cape Town. The teams have to overcome the harsh and unpredictable environments that South Africa has to offer, from the scorching sun in the Kalahari Desert to wide mountain ranges in the Western Cape.
Solar Team Twente
Solar Team Twente is a student team based in Enschede in the eastern part of the Netherlands. For over a year, students from the University of Twente and Saxion pause their studies to design and build the most efficient solar car in the world. Each time, the students challenge the boundaries of existing technology and showcase the possibilities of sustainable energy and transportation.
Every other year, they compete with their newly built car in the Bridgestone World Solar Challenge in Australia. Over the years, Solar Team Twente has had a number of significant successes, including multiple second-place finishes in Australia and a win in the special edition held in Morocco in 2021. Last year, for the first time, the team spent a year innovating a car that had already been built, with the goal to finish first during the Solar Challenge in South Africa.
Importance of accurate weather predictions
Having an efficient solar car is not the only factor that is crucial for winning a solar challenge. With the help of ECMWF's accurate high-resolution ten-day forecast, the students devised the most optimal strategy. Weather factors such as wind and solar irradiation significantly impact the ingoing and outgoing energy of the solar car.
A carefully planned strategy is required to efficiently distribute the car's battery energy over the eight days. To determine the strategy, ECMWF's spatial and temporal weather forecasts are used as inputs to a mathematical model, which the race strategists developed.
During the race, the model and weather inputs proved to be accurate and reliable. In the northern part of the country, for example, the model suggested driving relatively slowly to conserve energy, enabling the team to drive faster during the final stages of the challenge along the western coast. Accurate long-term forecasts were crucial for calculating the impact of short-term decisions on later stages of the race, ultimately helping to maximise the distance covered.
Finishing second
On 13 September, Solar Team Twente started their challenge, competing against the first- and third-placed teams of the Bridgestone World Solar Challenge from Leuven (Belgium) and Delft (the Netherlands). During the first four days, the teams were very even, with each team in first place at least once.
Unfortunately for Twente, on the fifth day, the team from Belgium took a decisive leap by driving nearly 100 kilometres more. Despite catching up during the final days and maximising every aspect of the car and the team, the gap was too significant to overcome. Solar Team Twente ultimately finished second in the challenge, covering almost 4,200 kilometres.
Aim for the future
Solar Team Twente participates in worldwide solar challenges to showcase the potential of renewable energy and inspire future engineers to develop sustainable solutions. Through their innovative solar-powered vehicles, they demonstrate how cutting-edge technology can address global issues like climate change. Private transportation, a major contributor to greenhouse gas emissions, urgently needs a shift towards cleaner alternatives. The mission of Solar Team Twente extends beyond competition, aiming to spark curiosity and drive progress towards a more sustainable future.