The Role of Mooring Line Monitoring in an Effective Asset Integrity Management of Floating Wind Farm

Abstract

As offshore wind farm developments move into water depth above 60m, one of the greatest challenges is in designing cost-effective mooring systems capable of overcoming the added risks of more severe environments, complicated floating structure response, and turbine forces. The failure of a primary mooring component could lead to unacceptable consequences, including destruction or complete loss of assets, loss of continuous electricity generation, possible retrieval of destructed structure, and possible injury or loss of human life during maintenance. It is essential to ensure that mooring systems operate without failure. Operators have recognized the importance of installing instrumentation such as GPS to monitor floating wind structure location. However, motion monitoring instruments have seldom been deployed on mooring lines of floating wind farm structures to capture dynamic response, which will govern the integrity of the mooring system and subsequently the whole floating wind structure. Measured data from these instruments on mooring lines allow an operator to determine when the limits of acceptable response, predicted by design analysis or scale model tests, could be exceeded in terms of strength and fatigue. This paper describes the role of mooring line monitoring in an effective asset integrity management of floating wind farm and provide a typical procedure for the development of a fit-for-purpose mooring line monitoring program. Furthermore, this paper presents an advanced monitoring method to capture the dynamic response of the mooring line by a cost-effective and maintainable solution.