Analysing failure statistics of wind turbines in Finland

The wind turbine statistics in Finland comprise data on monthly production and downtime from grid connected turbines. Production statistics have been compiled since 1992 and failure statistics since 1996. This analysis examines the failure statistics from 72 wind turbines between the years 1996-2008 and presents the disturbance time of different components as a function of the life time of turbines. The result is an estimate for the downtime of each component and can be used when developing systematic methodologies for preventive maintenance. Wind technology has developed rapidly during this period of time which has also had an effect on the type of failures occurring in wind turbines and the reasons for downtime