Sif Group

Sif Holding secured a contract from Two Towers to manufacture the monopile foundations for the Borssele V demonstrator offshore wind farm in the Dutch North Sea. The contract covered fabrication of two monopiles for the 19 MW innovation site, which comprises two large offshore wind turbines and serves as a pilot platform for new foundation and installation technologies. The monopile scope incorporated two distinct innovation features aligned with the project’s objectives. For one foundation, Sif manufactured a monopile designed for a slip joint connection between monopile and transition piece, using conical end pieces on the interfacing sections to enable a faster offshore assembly compared with conventional flanged or grouted connections. Sif noted that while similar concepts had been applied successfully onshore, offshore use had previously been limited to test applications; Borssele V provided an opportunity to demonstrate the approach at full scale. For the other monopile, Sif applied an aluminium-sprayed coating (Thermally Sprayed Aluminium) over a major part of the surface to reduce corrosion risk and minimise maintenance requirements over the operating life. Sif positioned the award as participation in Two Towers’ innovation programme at Borssele V, supporting cost reduction, installation efficiency, and improved environmental performance through new foundation solutions.