Proactive maintenance of offshore wind turbine blades using knowledge-based force analysis

The operation and maintenance (O&M) costs of wind turbines constitute approximately 10-15% of the lifecycle cost in onshore installations and up to 30% in offshore installations. The O&M costs for offshore wind power plants are higher than the onshore ones due to greater logistical challenges of maintaining and servicing, and the less mature state of offshore wind energy technology. Wind turbine blades suffer from various faults, for example, blade angle asymmetry, icing, and bends. These faults may cause wind turbines to a standstill. Replacement of rotor blades will normally result in a long downtime since the replacement process involves heavy transportation (vessel, crane) and dependency on weather conditions. This downtime can be shortened and the cost can be reduced if the replacement is done before the break and the wind turbine blade inspection and maintenance is scheduled effectively. The strategy that allows achieving the goal is called proactive maintenance. This paper introduces an approach to optimizing proactive maintenance of offshore wind turbine blades. The approach uses knowledge-based methods for force analysis. The approach solves the semantic ambiguity of offshore wind information and provides the possibility to monitor the performance of wind turbine blades in real-time, leading to advanced alarms when needed. The approach can be adapted and applied for other wind turbine components.