Design and Installation of Leading Edge, Practical and Economic Mooring Systems for Commercial Scale Floating Offshore Wind Energy

Abstract

As Floating Offshore Wind moves from demonstration and pilot projects to full commercial scale, there is a need for mooring systems to be practical and economic while providing safe and efficient stationkeeping for floating wind turbines. Mooring systems for floating offshore wind must be designed to meet the needs to provide a reliable stationkeeping system, satisfy turbine motions criteria for maximum energy production, accommodate electrical power transmission cables, allow for other marine users (e.g., fishing vessels, service vessels for inspections and maintenance, etc.) and be environmentally friendly. To be commercially viable, this must be done with an understanding of the need to moor 30 or more turbines in close proximity to one another with hundreds of mooring lines. To accomplish this, there is no one perfect mooring system for all projects. This paper will investigate multiple mooring solutions including various configurations and material types and will reveal both the technical and commercial benefits of the various systems. Multiple mooring systems will be designed to accommodate a 15 MW floating wind turbine. An installation methodology will be developed, and the supply chain will be investigated to enable calculation of the total installed cost of each system. The stationkeeping performance of each system will be compared as well as the economics for a large scale commercial floating wind farm. While no one system will be the clear best for all projects, guidance will be given which can aid in the selection of practical and economic mooring systems. The paper will investigate multiple viable mooring systems from the design, procurement, and installation viewpoint to develop total installed cost estimates. This will be done while evaluating these mooring systems for a large commercial size floating wind farm while addressing the need for the supply chain to deliver industrialized solutions to deal with the large scale.