An energy storage system (ESS) for electricity generation uses electricity (or some other energy source, such as solar-thermal energy) to charge an energy storage system or device, which is discharged to supply (generate) electricity when needed at desired levels and. An energy storage system (ESS) for electricity generation uses electricity (or some other energy source, such as solar-thermal energy) to charge an energy storage system or device, which is discharged to supply (generate) electricity when needed at desired levels and. Sandia National Laboratories supports these national interests through advanced research in power systems, generation and integration, energy storage, microgrids, cyber security, and enabling technologies including power electronics and advanced materials. Sandia's vision for enabling electric grid. As America moves closer to a clean energy future, energy from intermittent sources like wind and solar must be stored for use when the wind isn't blowing and the sun isn't shining. Energy storage reduces energy waste, improves grid efficiency, limits costly energy imports, prevents and minimizes power outages, and allows the grid to use more. Energy storage is defined as the capture of intermittently produced energy for future use. In this way it can be made available for use 24 hours a day, and not just, for example, when the Sun is shining, and the wind is blowing.