Tapping deeper offshore wind resources through floating wind turbines

Why is this gap important?

The richest offshore wind resource is located in deep waters, where attaching turbines to the seabed is not practical. Floating offshore foundations, offer the potential for less foundation material, simplified installation and decommissioning, and additional wind resource at water depths exceeding 50 m to 60 m. Several regions (e.g. the US or Japan) have a low share of their resource in shallow waters. Floating foundations may also be attractive for mid-depth projects, where saturation of onshore or near-shore potential or the possibility of standardising floating foundation designs and do not need heavy-lift vessels to transport foundations.

Technology solutions

New tools will be required to capture the design criteria for floating platforms, which include the need to address weight and buoyancy requirements as well as the heaving and pitching moments created by wave action. Current floating concepts include the spar buoy, the tension leg platform and the buoyancy-stabilised semi-submersible platform.

Vertical axis turbines, which disappeared from land, may have a second chance at sea. Although they have a higher material need to cover same swept areas and have some dynamical structural issues, their lower centre of gravity and fewer parts may be suitable in offshore wind. 

Gravity-based foundations Readiness level:

Colored bars represent the Technology Readiness Level (TRL) of each technology. Learn more about TRLs

What are the leading initiatives?

Two demonstrations show good performance: Hywind, with 30 MW in place; and US/PT, a 2 MW prototype off the Portuguese coast

Vertimed, an EU-funded project led by EDF-Energies Nouvelles with Nenuphar and Technip, aims to install around 20 MW off Fos-sur-Mer in the French Mediterranean

The US National Offshore Wind R&D consortium allocates USD 41 million in total to offshore wind research, with the first request for proposals as of March 2019 including developing innovative mooring and anchoring technologies for floating wind 

Other initiatives include Macquarie/Ideol's first floating wind farm in Japan and the Glosten tension-leg platform and Principle Power semi-submersible concepts.