One primary purpose of energy storage technology is its role in managing energy supply and demand, which significantly reduces energy costs. During periods of excess energy production—such as sunny afternoons for solar power—energy storage systems can capture surplus energy.
[pdf] Pumped storage plants can operate with seawater, although there are additional challenges compared to using fresh water, such as saltwater corrosion and barnacle growth. Inaugurated in 1966, the 240 MW in France can partially work as a pumped-storage station. When high tides occur at off-peak hours, the turbines can be used to pump more seawater into the reservoir than the high tide would have naturally brought in. It is the only large. Seawater-pumped storage is an innovative form of hydroelectric energy storage that harnesses the power of seawater as the lower reservoir in a two-tiered energy storage system. This approach offers a compelling solution for storing and regulating electrical energy.
[pdf] 
