Analysis of operation and maintenance strategies for floating offshore wind farms

Abstract

This report describes the computations that have been made to simulate the O&M cost for a generic floating offshore wind farm. The aim of this paper is to investigate if the floating foundation technology offers new approaches for the way offshore wind power plants are operated and maintained. The possibility to return the semisubmersible wind turbine to shore, allows that maintenance activities could be carried out near to shore (for example in a dry dock) with fewer restrictions and lower cost. The point of interest therefore is, to what extent it is technical and economical feasible to perform “offshore” maintenance in comparison with “onshore” maintenance for which the floating platform needs to be repositioned. This was studied by comparing the cost for each O&M strategy. Weather restrictions, distance to shore and the technology readiness level influence both concepts. In general, it can be concluded that with the current technology level, returning a semi-submersible floating wind turbine for scheduled maintenance campaigns on a regular basis is not an economical and technical feasible approach. Keeping in mind, that the floating wind turbine technology is still in the prototype and precommercial phase, this also concludes that there is still large potential for improvement.