Floating Offshore Wind Farm Maintenance Assessment Policies for Vessels Assignment

Floating offshore wind energy is expected to grow in the next years. The EU expects a great increase in the installed capacity of this incipient technology. Floating offshore wind farms can be located in deep water far from shore, reducing the visual impact and reaching a larger generation due to stronger winds. However, there are some challenges such as operation and maintenance (O&M). Maintenance's implementation of these floating systems is different from fixed offshore ones, resulting in new approaches like "towed to shore". Towing the turbines to shore or port must be done by adapted vessels according to maintenance actions. This work presents an assessment of a collection of scheduling maintenance policies for a floating wind farm assigning several vessels. A discrete state Markov chain is developed to model the deterioration process and to establish the different actions to take. Maintenance policies are based on time or based on the condition of turbines. Results show that, in general, Index policy keeps the farm in a lower state of deterioration, being the O&M cost of this policy similar to the cost incurred with the Naive policy. Both, Periodic and Threshold policies reach the worst results in terms of O&M costs and deterioration.