Economic analysis of condition monitoring systems for offshore wind turbine sub-systems

The use of condition monitoring systems on wind turbines has increased dramatically in recent times. However, their use is mostly restricted to vibration based monitoring systems for the gearbox, generator and drive train. There are many forms and types of condition monitoring systems now available for wind turbines. A survey of commercially available condition monitoring systems and their associated costs has been undertaken for the blades, drive train and tower. This paper considers what value can be obtained from these systems if they are used correctly. This is achieved by running simulations on an operations and maintenance model for a 20 year life cycle wind farm. The model uses Hidden Markov Models to represent both the actual system state and the observed state. The costs for system failures are derived, as are possible reductions in these costs due to early detection. Various scenarios are simulated including the addition of condition monitoring systems to the drive train and blade and tower monitoring. Finally, the efficacy of these systems is examined and its effect on operation costs.