Danish energy technology firm Stiesdal has started production of its new TetraSub floating wind foundation, designed to support the next generation of larger offshore wind turbines, the company announced on Monday.
The move comes four years after the installation of its TetraSpar floating wind demonstrator at the Marine Energy Test Centre off the coast of Norway. Installed in 2021 at a depth of 200 metres, the 4-megawatt (MW) TetraSpar prototype marked the first full-scale demonstration of an industrialised floating offshore wind foundation. Stiesdal said the demonstrator has since delivered “solid operational data.”
The TetraSpar project is a collaboration between Stiesdal Offshore, Shell, RWE, and Tepco Renewable Power.
The newly launched TetraSub is a semi-submersible variant of the Tetra design, intended for water depths between 50 and 200 metres—a range expected to dominate the floating offshore wind market through 2030.
Until 2030 it is expected that the largest part of the floating offshore market will be at relatively shallow water, with depths within the 50–200 metre range,” Stiesdal said in a statement. “The floating wind market is likely to evolve initially as an extension of the fixed-bottom market, which typically has a maximum depth of between 50 and 60 metres.
The company added that the Tetra platform is engineered to scale with the industry’s growing turbine sizes, noting that the design can accommodate turbines rated up to 20MW without requiring major design changes.
The launch of TetraSub reflects broader trends in offshore wind, where developers are increasingly exploring floating solutions to unlock deeper water sites and expand capacity beyond the limits of fixed-bottom foundations.
