Cost simulations for ancillary services

A probabilistic method has been developed with the aim of better understanding the factors that influence costs related to providing ancillary services from hydropower units. This study primarily focuses on costs related to factors influencing the probability of unplanned disturbances, failures and break-downs. It describes the implementation of the method and simulation tool. Some example cases are included and discussed. The results indicate that costs related to the provision of ancillary services from hydropower plants can be the same order of magnitude as the revenue from selling the services to the market.