Japanese construction company Kumagai Gumi has joined Saitec Offshore Technologies and Kansai Electric Power Company (KEPCO) in the DemoSATH floating wind project in Spain, with the partners extending the prototype’s operation at the BiMEP test site through 2027.
Under a cooperation agreement, the partners will use the extended operating period for research, technology optimisation and knowledge transfer. Kumagai Gumi will focus on improving decommissioning methods and assessing construction procedures that could support mass production of floating wind platforms.
The project is moving into a new phase after demonstrating Saitec’s SATH (Swinging Around Twin Hull) technology under real offshore conditions. The partners will use operational data from the prototype to study its structural and dynamic behaviour, improve monitoring and predictive modelling, and support the design of future commercial-scale floating wind farms.
DemoSATH consists of a 2 MW wind turbine mounted on a concrete twin-hull floating platform. Located around 3.2 kilometres off the Basque coast at the BiMEP open-sea test site near Armintza, the prototype sits in approximately 85 metres of water.
The platform was assembled at the Port of Bilbao and installed offshore in 2023. It began generating electricity and feeding it into Spain’s grid in September that year, marking the country’s first floating offshore wind turbine to deliver power to the grid. In September 2024, the platform received final prototype certification from Bureau Veritas.
During its operation, DemoSATH has collected data on the platform’s performance in the demanding conditions of the Cantabrian Sea, including waves of up to 13 metres and wind gusts of 144 kilometres per hour, according to the project partners.
The prototype has also served as a test platform for environmental monitoring and research into how floating wind installations can coexist with marine ecosystems, including potential applications related to aquaculture.
The extended programme will build on the experience gained during the initial demonstration phase, with the aim of transferring the results to larger floating wind projects in international markets.