Renewable energy sources (RES) based distributed generation (DG) system results reduction of overall system inertia, which is likely to generate higher oscillations in the system during disturbance conditions. Therefore, DG penetration level has a significant impact on system stability and reliability. This study provides an in-depth analysis of battery energy storage system (BESS) impact in providing primary frequency control to support increased wind penetration level. The BESS is modeled as a storage system with DC/AC converter and other associated power electronics interfaces. The objective is to replace the existing synchronous generator in proportion with the increasing penetration level of wind units while maintaining power system stability and reliability. The BESS model is developed in DigSILENT/PowerFactory and the system performances are simulated and compared with and without the BESS considering different disturbances such as single-phase-to-ground fault, and temporary line outage and load demand increment with various DG penetration level. It is shown through simulation results that BESS exhibits the ability to reduce system oscillations following disturbances and supports the increment of DG penetration level in the existing power system. Therefore, BESS can be seen the most viable measure of stability enhancement with renewable oriented sustainable future electric grid.