The Effect of Large-Scale Wind Power on System Balancing in Northern Europe

The ongoing development in the electrical system and the transition from a mainly thermal dominated power system into a system widely affected by renewable production resources, requires a revision of future balancing strategies facilitating the secure integration of renewable energy. Especially the increasing wind power penetration with its uncertain production on all time scales will largely affect the system operation, requiring a higher flexibility and thus more reserve capacity providing balancing energy. Based on high resolution numerical weather prediction models and wind speed measurements, the actual and the forecasted wind power production is simulated for five scenarios covering the years 2010 and 2020. These scenarios are taken as an input to a Northern European regulating power market model, analyzing the procurement of reserve capacity and their activation. Further on, the potential benefit of integrating Northern European regulating power markets handling the varying wind power production is investigated. Due to remaining wind forecast errors, more reserve capacity is required in the electrical system. The simulations comprise frequency restoration reserves and replacement reserves. Based on the assumption of an integrated regulating power market, the determined results illustrate that the Nordic power system can provide such reserves at optimal cost. In 2020, an overall cost increase is recognized, concurrently displaying significant saving possibilities by a cross-border procurement of reserve capacity and the exchange of balancing energy.