The critical integration of renewable energy sources into power systems relies heavily on the Battery Energy Storage System (BESS). Parameters such as capital investment, discharge time, compatibility with the energy source type, and the size of the power system are crucial for selecting the most appropriate energy storage solution. This paper conducts a comparative analysis of various energy storage systems that can be utilized in conjunction with renewable energy resources. Additionally, the capacity estimation for an energy storage system is carried out using a 1 kW PV source as a test model. The results show promise, indicating that a similar approach could be applied to determine the capacity for various other energy storage systems. The author reviews cutting-edge methods available for storage systems in micro-grid and grid-scale applications.