Posters

Abstract

The current preferred method for major component replacement (MCR) for floating offshore wind is tow to port. A relevant subtopic is dynamic cable management, and the impact on lost production. For wind farms with daisy chain configurations, cable management strategies impact both marine operation cost and lost production for any turbines connected via the removed floater. The current state of the art solution is to cut and seal cables for wet storage, and pick up the cables when the floater returns. Other solutions, e.g. a splice box to ensure electrical continuity for the remainder of the string is under consideration but not yet commercially available. A market study revealed that two cable manufacturers planned to develop such splice boxes, a third company had spent time developing a solution without finalizing the product. More innovative solutions have been considered. One foundation supplier has a concept that address the issue, but details regarding its use are not publicly available, and it seems not to be in use on the foundations the supplier has delivered. Other ideas, such as a turret solution combining mooring and cable connection in a disconnectable unit has been proposed, but may be too costly. Other inter array layouts than daisy chain, e.g. hub solutions or daisy chains connected in a ring, will eliminate or reduce the impact of lost production when a floater is removed. This paper presents a methodology for capturing the costs and benefits for various dynamic cable management options during tow to port. It shows that the current state of the art solution is sub-optimal, and that a splice box is optimal to use for most tow to port operations. Furthermore, the avoided lost production during tow to port for ring and hub inter array layouts is substantial, and should be considered when selecting layouts.