The incorporation of renewable energy into large-scale systems exhibits technical problems due to power fluctuations. As an alternative solution to control these fluctuations, an implementation of energy storage systems can be considered. However, an oversizing of storage capacity may cause the project to be non-viable and inefficient. To determine accurately the storage capacity, a proposal for an optimization model, based on the wind speed information in the area, is being made in order to minimize the energy required to keep at the farm’s output the desired power reference. The power reference is calculated with the segmentation method and the differential evolution technique. The control strategy of the storage system is based on the control scheme established by the Electric Power Research Institute. The proposed method, power control, and the dynamic model of energy storage system offers a tool to make studies for the connection of wind power into power systems.