What is an energy storage system?

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 quality. ESSs provide a variety of services to support electric power grids.

Are energy storage systems safe for commercial buildings?

For all of the technologies listed, as long as appropriate high voltage safety procedures are followed, energy storage systems can be a safe source of power in commercial buildings. For more information on specific technologies, please see the DOE/EPRI Electricity Storage Handbook available at:

What makes energy storage unique?

One attribute that makes energy storage unique is its scalability. It can be implemented as a large utility-scale project to help meet peak energy demand and stabilize the grid, or as a small system sited in a residence or commercial facility to manage electricity costs and provide backup power.

Will energy storage change the dynamics of a grid?

With widespread grid failures on this scale, energy storage would have to make up a much larger share of system capacity than it currently does to change the dynamics, although it can respond to sudden system fluctuations by providing ancillary services, like frequency and voltage regulation.

Are distributed energy storage systems a good option for emergency situations?

Distributed energy storage systems equipped for emergency scenarios, however, do have the potential to soften these types of hardships. These systems could help residents power critical loads, such as heaters during extreme cold or plug-in medical devices, while the power is out.

What is the power capacity of a battery energy storage system?

As of the end of 2022, the total nameplate power capacity of operational utility-scale battery energy storage systems (BESSs) in the United States was 8,842 MW and the total energy capacity was 11,105 MWh. Most of the BESS power capacity that was operational in 2022 was installed after 2014, and about 4,807 MW was installed in 2022 alone.