The next phase for offshore wind

Jeonnam 1 OWF is the first commercial offshore wind farm in South Korea and is nearing completion with an expected delivery of first power set for later this year. The project is a 51-49 joint venture between SK E&S and Copenhagen Infrastructure Partners (CIP).

Situated off the coast of Shinan County in Jeonnam Province, the finished wind farm will add 99 MW of clean energy generation to the Korean grid, effectively doubling the country’s current installed capacity of 100 MW.¹ The wind farm is expected to produce green electricity equivalent to the consumption of approximately 60 000 households in South Korea.

The project encountered various technical challenges throughout the design phase. Most notably the engineers had to deal with significant seabed mobility – a challenging phenomenon where the entire seabed in the area is being exposed to either erosion or sedimentation over time. A considerable amount of engineering effort was dedicated to accurately incorporate this phenomenon into the design process. The approach resulted in a foundation design that balances the necessary conservatism with optimal efficiency. The site’s water depth ranges from 5 – 20 m with the selected solution of steel monopile foundations featuring an 8 m diameter. Scour protection measures around monopiles are essential at the site, yet they cannot counteract the potential global seabed lowering occurring beyond the protected area. Due to the combination of seabed mobility and environmental conditions, including shallow water depths at some of the locations, identifying a uniform design for scour protection proved challenging.

This situation required conducting physical model tests to develop tailored scour protection strategies that could effectively address these unique conditions. A joint effort between the project owners, the transport and installation contractor, COWI, and Deltares, a world-leading institute in the Netherlands, made it possible to find the optimal scour protection solution at Jeonnam 1 OWF, accounting for the challenging conditions at the positions investigated.

The process shows how digital tools can help when an offshore wind project is challenged by a complex environment. This is key for further scaling up the industry, since the power of digital models and big data sets this way can help realise offshore wind farms on sites that previously would have been deemed too expensive or risky to utilise.

COWI has come to rely on a number of digital platforms whenever it helps design the world’s large offshore wind farms. The company develops some of the software itself, and one of the more recent tools to be added to its kit is called COWIND Digital Toolchain. It is specifically designed for optimising the design of monopile foundations for offshore wind turbines. This platform takes into account thousands of parameters to determine optimised and consistent designs for each foundation. It operates in the cloud, allowing for scalability and adaptability to changing design requirements. COWIND Digital Toolchain is flexible and can be customised to meet project-specific needs while ensuring adherence with ISO 9001 requirements for traceability and standardisation.

Another example of a useful digital tool is COPILOD, which allows for the direct generation of design drawings and reports. It significantly speeds up the production of foundation designs, reducing costs and resources by up to 80%. Further, COWI de-ploys COSPIN and COWAL as support systems. COSPIN is used for geotechnical design checks, while COWAL generates wave loads. These systems automate processes and improve efficiency in the design phase.

Software platforms and tools like these have become indispensable in order to streamline the design process, reduce costs, and improve efficiency in offshore wind farm projects and the industry will undoubtedly move towards a more digitalised and data powered approach to design in the years to come. For both the Jeonnam 1 project and other recent offshore wind farm projects, the software has been essential to standardising the foundation design across the several foundation units found within any offshore wind farm. This standardisation process is saving costs, and it also simplifies the manufacturing process, and the installation phase for the offshore wind farm project.

Jeonnam 1 OWF’s foundation solution also comprises innovative installation solutions. The embedded part of the foundation being either composed of a monopile (MP) driven to target depth with an impact hammer or composed of several structural components: MP, insert pile (IP) and grout annulus, to form a rock socket. COWI’s extensive experience with drilled monopile foundations played a crucial role in this strategic decision, ensuring the foundation’s adaptability and resilience to the site’s conditions.

Enjoyed what you've read so far? Read the full article and the rest of the Summer issue of Energy Global by following the link or below, or why not register today for free!

For more news and technical articles from the global renewable industry, read the latest issue of Energy Global magazine.

Energy Global's Summer 2024 issue

The Summer 2024 issue of Energy Global starts with a guest comment from Terrawatt on the streamlining of the permitting process in Italy, before moving on to a regional report from Frost & Sullivan on the energy landscape in Asia Pacific. This issue looks at key topics such as wind installation vessels, offshore wind turbine foundations, weather analysis, solar maintenance, and more!

Read the article online at: https://www.energyglobal.com/special-reports/17062024/the-next-phase-for-offshore-wind/