With its 11 floating wind towers using concrete SPAR buoys, Hywind Tampen is a pilot project for the offshore wind power industry. This technology is based on post-tensioning to ensure optimal resistance and durability of the structure, in a harsh environment where the wind towers are subject to extreme loads imposed by the wind and the ocean (waves, currents, drifting ice blocks…). Installed west of the city of Bergen, the 88 MW floating wind farm will supply electrical power to the nearby oil and gas platforms.

VSL contributed to this world’s-first:  the teams have performed the post-tensioning works of the concrete structures, consisting of tendons up to 88m in vertical length, and installed offshore. The 660 post-tensioned tendons have been fully prefabricated by VSL and transported to site ready for installation. With no access along the vertical tendons, all the post-tensioning operations have been done from the top of the concrete structures. 

Combining an optimized construction process, with resistance, durability, and almost no need for maintenance, have allowed the SPAR buoy solution to emerge as an efficient solution for floating wind farms in deep waters, where the wind is faster and steadier.