Development and demonstration of 'float and sink' gravity base foundation (FSF) for offshore wind turbines

Background
The industry to date has predominantly utilised monopile solutions with jackets and GBFs requiring specialist installation equipment. These foundation types, even if suitable for deeper waters, present a number of challenges to the development of the sector, for example: piling, piling noise, and the availability and cost of specialist installation vessels. While GBF have been used previously no FS GBF solution has been installed for an offshore wind turbine. It is widely accepted that this type of solution will be required to exploit the potential of offshore wind globally. Successful demonstration of an FS GBF project would prove the technical feasibility of the solution and enable further refinements of the design for mass manufacture and
deployment.

Objective
Potential benefits of using a FS GBF solution include:
• Lower installation costs by employing standard tugs and self-buoyancy rather than specialised vessels.
• Reduced costs deriving from the elimination of piling.
• Reduced environmental impacts through noise mitigation techniques.
• Lower costs in the mass-manufacturing phase, as personnel costs will be lower in this process.
• Lower costs during the operational phase as a result of reduced inspection and maintenance.
• The option to manufacture and deploy the FS GBF in physical proximity to the offshore site.
• Increased deployment of WTGs in sites where piling is not technically feasible.

Short description of activities
The FSFOUND project seeks to install 5 FS GBFs in the first array of BOD. FS GBFs for offshore wind turbines have been designed to a prototype stage but have not yet been deployed (TRL6). An objective of this project is to advance the technology such that at the end of the project the FS GBF system will be fully demonstrated and will be deployed in an operational environment.