This paper presents a methodology to optimize the capacity of a Battery Energy Storage System (BESS) in a distributed configuration of wind power sources. A new semi-distributed BESS scheme is proposed and the strategy is analyzed as a way of improving the suppression of the fluctuations in the wind farm power output. The model is tested for a similar wind power profile where the turbines are located at close geographic locations with similar geographic conditions. This power profile is also assessed under a variety of hard system constraints for both the proposed and conventional BESS configurations. It was proved that the performance of the proposed semi-distributed BESS scheme is better than that of conventional approaches, based on the results validated with real-world wind farm data.