Mobility on the water is becoming increasingly important – whether in tourism, recreational sports or as an alternative to road transport. But what might an environmentally friendly future on the waterways look like? The Swiss Solar Boat (SSB) project at EPFL MAKE – an initiative of the Swiss Federal Institute of Technology in Lausanne (EPFL) – provides an answer. Thanks to the commitment of 75 EPFL students, the vision of lower-emission waterborne mobility is becoming a reality. They developed the Renewable Energy Foiler (REF), a hybrid boat powered by solar and hydrogen, and impressively demonstrate how engineering and sustainability can go hand in hand to create new possibilities in maritime technology.
Milestones: From Dahu to the Renewable Energy Foiler (REF)
The history of the Swiss Solar Boat (SSB) project is marked by technological milestones. One particularly outstanding project is Dahu, the world’s first foiling proa. This unique boat is lifted above the water’s surface by foils – special underwater wings – which significantly reduce water resistance.
In 2021, Dahu won an eco-design award at the Monaco Energy Boat Challenge and secured first place in the championship race in 2022. In 2024, the team demonstrated the technology’s practical viability when Dahu crossed Lake Geneva from Lausanne to Évian. In doing so, the boat demonstrated the great potential of hydrogen as an emission-free energy source for marine propulsion. This success formed the basis for SSB’s next project – the Renewable Energy Foiler (REF).
Consistently refined: Renewable Energy Foiler
The REF is a technological advancement of Dahu. In this three-person boat, the hydrogen propulsion is supplemented by solar energy, resulting in a highly efficient hybrid propulsion system in terms of speed and range. With a top speed of 35 knots (65 km/h) and a range of 160 to 250 kilometres, the boat is setting new standards in maritime mobility.
The REF has been under construction since summer 2024 and is now entering the crucial phase of electronic integration. The project’s goal is clear: come spring, the REF is set to glide across the lake against the breathtaking backdrop of the Swiss Alps and be showcased on an international stage at the Monaco Energy Boat Challenge 2026.
Challenges overcome
One of the key challenges in developing the Swiss Solar Boat was selecting a suitable CAN communication cable that met the project’s high technical requirements. The cable not only had to have 2 or 4 conductors and be well shielded against interference, but also have a sufficiently thin outer diameter to fit easily into the boat’s cable connectors. These specific requirements significantly limited the options available. However, with the support of the experts at LAPP SWISS AG, a suitable solution was found and LAPP supplied one of the few cables that met all the technical criteria.
In addition to the CAN communication cables, other LAPP products were used. Cable glands in various sizes were employed to route the cables securely through the boat’s bulkheads whilst ensuring a watertight seal – an essential feature for protecting the sensitive electronics from external influences. Furthermore, cable lugs played a vital role by reliably connecting the boat’s high-current components to the electrical system. Thanks to the reliable and prompt delivery of the required components, the project was implemented swiftly without any significant loss of time.
Collaboration with strong partners: A key to success
The Swiss Solar Boat project benefited from the support of partners such as LAPP, who made a significant contribution to ensuring the project’s operation and efficiency by supplying key components.
However, the Swiss Solar Boat is more than just a technical endeavour – it is a vision driven by a team of dedicated students with creativity and technical expertise. Through collaborative partnerships with industrial companies, the project has demonstrated that innovative ideas and the right technical components can push the boundaries of what is possible. The combination of technological developments such as foils, hydrogen propulsion and sustainable design, together with the international showcase at the Monaco Energy Boat Challenge, make the Swiss Solar Boat a model for future development in the maritime sector – and give hope for further exciting projects.