Generolo Jono Žemaičio Lietuvos karo akademija

Energy security is conditioned by numerous factors, among which solutions and patterns of energy storage play important role. Electrical energy storage (EES) is the process by which energy is stored from the power network to a form which can be used later when converted back to electrical energy. There are various ways by which electrical energy can be stored for future purposes. Nowadays, the electrical energy is mainly stored in pumped hydroelectric energy storage (PHES) that comprises about 99% of EES worldwide and the battery energy storage (BES) that uses chemical energy with both methods yielding characteristic advantages and disadvantages. Electrical energy is mainly stored when there is low demand and when there is high generation of power at low costs. The energy is then used when there is high demand of power and the generation cost is high or when there are no other means of generating electrical energy. Electrical energy storage has many uses such as in the electrical devices, motor vehicles and stationery energy resources and is gaining special attention with the widespread usage of renewable energy sources (RES).