The Department of Energy released a Grid Energy Storage report that identifies the benefits of grid energy storage, the challenges that must be addressed to enable broader use, and the efforts of DOE, in conjunction with industry and other government organizations, to meet those challenges.
At present, the US has about 24.6 GW (about 2.3 percent of total electric production capacity) of grid storage, 95 percent of which is pumped storage hydro, while Europe and Japan have notably higher fractions of grid storage. Pursuit of a clean energy future is motivating increased storage development efforts in Europe and Asia, as well as the US.
Energy storage technologies – such as pumped hydro, compressed air energy storage, various types of batteries, flywheels, electrochemical capacitors, etc., provide for multiple applications: energy management, backup power, load leveling, frequency regulation, voltage support, and grid stabilization. Importantly, not every type of storage is suitable for every type of application, motivating the need for a portfolio strategy for energy storage technology.
According to the report, there are four challenges related to the widespread deployment of energy storage: cost competitive energy storage technologies (including manufacturing and grid integration), validated reliability and safety, equitable regulatory environment, and industry acceptance.