Maximizing value through optimized annual selection of Pareto-optimal wind turbine operating strategies

Wind turbines as an investment aim at turning an initial expense into a profit. Naturally, the aim of developers and operators alike is to create an economic benefit that is as high as possible. Little changes to a wind turbine structure are possible once it is built, and wind as the ultimate power source cannot be influenced. The only available means to achieve a high economic benefit is through improved operations and maintenance. We developed a method for optimizing the operation of wind turbines that builds on condition-based adaptation of the power setpoint. It aims at balancing loads and power generation such that lifetime is increased, and the total economic value is improved over simpler operating schemes. In this contribution, we extend the method with an annually varying selection of different optimal operating strategies from an initial multiobjective optimization. We show three case studies that highlight the potential of annual variation and the margin with which it improves on operating at nominal power and over a fixed optimized operating strategy. In each case study, the net present value can be improved slightly over a lifetime-constant operating point that is selected once from the Pareto-front.