A model for assessing operation and maintenance cost adapted to wind farms in cold climate environment: based on Onshore and offshore case studies

The cumulative costs for O&M may represent as much as 65%-90% of a turbine's investment cost. The higher cost ratios are valid for offshore farms and for onshore farms located in cold, icy or remote areas. The ongoing studies conducted by wind energy in cold climates (IEA- Task 19) concluded that the increased O&M costs and extended downtime under icing conditions have to be taken into account. Therefore, in this study we developed a model for assessing the O&M cost of wind farms operated in cold climate. The model was verified using two methods: season-categorised method for downtime based on data reported by VTT and temperature-categorized method for production losses based on data collected from Aapua wind farm. Using the developed model gives a better understanding of the O&M cost of wind power systems taking into account relevant contextual factors. As well as, it helps the stakeholders to improve their decisions at different phases of the system's life cycle