System reliability of floating offshore wind farms with multiline anchors

Abstract

This research assesses the reliability of floating offshore windfarms utilizing two different anchor configurations: a conventional single-line system in which each anchor is loaded by a single mooring line and a multiline system in which each anchor is loaded by three mooring lines. While there are advantages to adopting a multiline system for floating offshore wind farms, the interconnectedness of this concept introduces disadvantages, such as reduction of system reliability and the potential for cascading failures among multiple structures. The reduction in system reliability is investigated here by running Monte-Carlo simulations in which mooring line and anchor demands and capacities are sampled from probability distributions. Demand distributions are generated through dynamic simulations with environmental conditions corresponding to the 500-year storm. Failure of mooring lines or anchors are initiated when their capacity is exceeded by their demand. The results of this research show that the reliability of the multiline system degrades significantly when progressive failures are taken into consideration. This research also shows that design considerations, such as the sizing of mooring lines and anchors and designing for single-line or multiline loads, significantly influence the system reliability of a floating offshore wind farm.