Innovative Single-Day Installation Vessel for Offshore Wind Turbines

Abstract

Transportation and installation of a wind turbine system is one of the main factors for business availability of offshore wind power due to its high cost and technical difficulty. The purpose of this study is to develop an innovative transportation and installation method for offshore wind turbines. We refer to this installation process as an All-In-One-Installation (A.I.O.I), and the special vessel used is referred to as a multipurpose mobile base (MMB). In this study, the short-range transportation and penetration and pull-out tests of the entire wind turbine system are performed before field demonstration. All the offshore wind turbine systems were transported and installed safely at one time. Field demonstration was conducted on the installation site approximately 15 km from the harbor in approximately 5 h using the suction method. In the actual A.I.O.I demonstration test, stable values were obtained. The respective changes in inclination at the center of the MMB and the tower were within 0.1° and 0.2° during operation, respectively, because of the reduction of longitudinal and transverse sway of the MMB induced by the self-weight assembly and ballast. The presented method constitutes an innovative transportation and installation method useful for the offshore wind power industry demonstrating single-day installation feasibility. This installation method can be used to configure the fleet in the development of large-scale offshore wind farms, but it is also possible to install turbines in individual units for research or small businesses. With minor A-Frame modifications, it can be applied as a multipurpose vessel to maintain the blades or heavy components, or can be used for pile driving, or for the lifting/installation of offshore structures.