Energy Storage Systems (ESS) are technologies that store energy for later use, helping to balance supply and demand in power systems. They play a crucial role in integrating renewable energy sources like solar and wind, which can be intermittent. By storing excess energy generated during peak production times, ESS ensures a reliable energy supply when demand is high or generation is low. These systems come in various forms, including lithium-ion batteries, pumped hydro storage, and flywheels. Each type has its own advantages and applications, making ESS essential for enhancing grid stability, reducing energy costs, and supporting the transition to a more sustainable energy future.