DNV is calling for industry partners to collaborate in delivering a recommended practice that provides clear guidance on the expectations for projects adopting a holistic approach to improve ground characterization for offshore wind developments. This initiative will be part of the ambitious joint industry project (JIP) Ground Investigation for Floating Wind (GIFT)
With the global surge in floating wind projects on track to reach commercial scale, mid-range estimates by DNV's Energy Transition Outlook Report 2024, predict a little bit more than 7 GW installed by 2030 using 10-20 MW floating turbines. With 3-5 anchors per turbine, this translates into 1,000-3,500 anchors to be installed by the end of the decade.
Through the GIFT JIP, DNV and industry partners will work towards developing a recommended practice on Site Investigations (SI) that enables the safe derivation of design soil profiles for installation and in-place performance.
"It is of great importance to join the know-how as the industry begins to tackle new challenges in developing large-scale offshore floating. There is a need to optimize site soil characterization within project timelines to facilitate reliable designs, standardization, and installation of station-keeping systems. For this, clear guidelines, recommended practices, and minimum requirements are key to provide confidence for decision-makers and investors," said Alejandro Borobia, JIP project sponsor at DNV.
The new practice aims to move away from position-specific (anchor/foundation) in-situ testing by utilizing a more practical environmental class approach. This work will be conducted through a pragmatic approach for geophysical and geotechnical SI and state-of-the-art ground modeling, aligned with project timelines and ensuring adequate knowledge of the ground conditions to facilitate reliable anchor design, accommodate design flexibility, and de-risk installation.
"The potential of correlating geotechnical and geophysical data is often overlooked. I very much look forward to steering the collaboration between geophysical and geotechnical engineers. Their insights will be key for optimizing ground models for anchor design and installation," commented Amy Beeston, JIP technical lead at DNV.
The proposed approach for site investigations will also be applicable to fixed-bottom foundations or seabed cable developments. The JIP aims to establish an approach for defining a design soil profile without the need for position-specific data, thus creating a framework where the site investigation can be de-associated from the final wind farm layout. This has the potential to remove the site investigation from the critical path of project development for both floating and bottom-fixed WTG or cable corridors, allowing for late layout and/or design changes.
"The project idea might have been initiated from the necessity for addressing a critical issue for the floating wind foundations but is not limited to that. The JIP aims at establishing a procedure for site conditions assessment that enables developers to tailor site investigation to their project's needs and schedule," added Yiorgos Perikleous, JIP project manager and technical lead at DNV.
The JIP initiative was launched with an initial workshop in Q1 2024 following active discussions with more than 20 companies. The JIP is planned to take place over a period of 1.5-2 years, starting in Q4 2024. However, the call for additional interested partners remains open, and DNV welcomes companies spanning various interests (operators, designers, contractors, regulators) to join.
Partners in the JIP will participate in technical workshops, receive early access to the knowledge gained, and get insights into the resulting recommended practice. Currently, several parties, including developers, site investigation contractors, anchor manufacturers, and consultants, have expressed their interest in the JIP.
