Spare Parts Planning for Offshore Wind Turbines Subject to Restrictive Maintenance Conditions

The use of offshore wind energy is supposed to play a significant role in future energy supply. Because offshore wind farms will be built in greater water depths and distances to shore according to other already realized offshore projects, maintenance is far more influenced by different restrictive factors. Limited availability of vessels, dependency on meteorological surrounding conditions, such as wind speed and weave height, as well as a complex logistical process chain require adjustment of up to now implemented maintenance concepts. In this context ensuring a reliable and cost-effective supply of spare parts is of great importance. This paper describes an approach for spare parts planning by considering restrictions that exist in the field of offshore maintenance. The model developed is used to show how restrictive factors influence maintenance and operation costs and how spare parts supply processes can be adopted. Scenario analysis will be used to estimate time of preventive maintenance activities and to investigate stock out costs caused by the restrictive accessibility.