Opportunistic Maintenance in Offshore Wind Farms

Harvesting offshore wind energy will grow significantly in the future as investments in large scale wind farms will take place. Already in early 90’s wind energy industry has stepped offshore due to a number of interesting characteristics compared to onshore wind yield. In early cases the offshore farms were installed in low water depths and small distance to shore. Future wind farms will be installed further from shore where the wind speed is higher thus the energy production. This new approach will lead to higher Operations & maintenance costs are functioning under a harsh maritime environment and thus their accessibility for maintenance is influenced by sea-state (i.e. waves) and weather conditions(i.e. wind). What is more, visiting an offshore wind farm is more costly as their distance from shore creates problems in their accessibility. In this Master Thesis, a way to optimize maintenance strategies in an integrated manner will be attempted. For that reason, parameters such as environmental conditions which influence the accessibility of an offshore wind farms will be taken into account. The main cost savings are related to the production losses and logistic costs including fuel and mobilization costs. The proposed model is trying to minimize the maintenance costs by decreasing production losses and transportation costs. Wind speed and Wave heights of the period 1993 until 2012 are used to simulate the wind and wave pattern. A cost comparison is made for the different locations and for different weather scenarios in order to prove the importance of both elements. The results showed that savings can be achieved with the proposed model even in harsh weather conditions.