Review and Cost Analysis of Anchored Foundation for Floating Offshore Wind Turbine

  Objective  Cost reduction is currently the primary task and target for floating offshore wind farms, and the anchored foundation, as a critical component of such a system, is subject to cost reduction accordingly.

  Method  The cost of anchored foundation could be reduced by selecting optimal type of anchored foundation, adopting shared anchored foundation and developing novel type of anchored foundation. By a review of the current application of anchored foundation in existing floating offshore wind projects, a comprehensive statistical analysis was conducted on the types of anchored foundation for prototype and demonstration projects both in and out of China. Then a further study was performed to evaluate the impacts of three distinct anchor types: drag embedment anchor, suction anchor, and pile anchor which were on the total cost of anchored foundations (inclusive of construction, installation, and recovery costs) under varying water depths (50 m and 100 m) at the same site with the same mooring tension. The research progress on shared mooring and innovative anchoring technologies was also outlined.

  Result  The statistics indicate that, except the Windfloat project whose anchored foundation employs the drag embedment anchor design, the anchored foundation of most constructed floating offshore wind prototype projects and demonstration projects predominantly employs the suction anchor design. The cost comparison analysis reveals that the total cost of the suction anchor design is lower than that of the pile anchor design, and the drag embedment anchor design is the most cost-effective type. However, drag embedment anchor is challenged by complex installation and positioning difficulties, and is not suitable for shared anchored foundation.

  Conclusion  The suction anchor design shows good adaptability in floating offshore wind farms and is poised to become increasingly competitive in deep-sea environments. The shared suction anchor design is anticipated to emerge as the predominant anchored foundation solution for future floating offshore wind farms.