This work presents a thorough study of mechanical energy storage systems. It examines the classification, development of output power equations, performance metrics, advantages and drawbacks of each of the mechanical energy storage types and their various applications in the. Hence, mechanical energy storage systems can be deployed as a solution to this problem by ensuring that electrical energy is stored during times of high generation and supplied in time of high demand. It examines the. Energy-storage technologies play a pivotal role in enabling the effective integration and utilization of intermittent renewable energy resources, particularly solar and wind power, by stabilizing supply–demand fluctuations and ensuring grid reliability. These technologies are widely deployed. A paradigm transition from centralized to decentralized energy systems has occurred, which has increased the deployment of renewable energy sources (RESs) in renewable energy communities (RECs), promoting energy independence, strengthening local resilience, increasing self-sufficiency, and moving. Mechanical energy storage methods are defined as those systems whose primary form of stored energy is kinetic or potential energy. The. Mechanical energy storage works in complex systems that use heat, water or air with compressors, turbines, and other machinery, providing robust alternatives to electro-chemical battery storage.