This is a list of energy storage power plants worldwide, other than pumped hydro storage. Many individual energy storage plants augment electrical grids by capturing excess electrical energy during periods of low demand and storing it in other forms until needed on an electrical grid. The energy is later converted back. • • • • • • • • Energy storage is the capture of produced at one time for use at a later time to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an or. Energy comes in multiple forms including radiation,,,, electricity, elevated temperature, and. Ene.