NRG Spring has developed a proprietary technology that provides a storage system for a variety of applications, ranging from short-term grid stabilizers to long-term bulk energy storage to portable battery replacement. The companys system can store any type of energy in hydraulic batteries (accumulators). The energy is first converted into kinetic rotational energy which operates a hydraulic pump that stores the energy as pressurized oil. On demand, a managed release mechanism discharges the pressurized oil into an hydraulic motor that is connected to a generator, releasing the energy as electrical current.