California Energy Storage System Survey

Energy Storage in CA by Type. Two batteries, left one shows current values, commercial: 540 MW; residential: 843 MW; Utility: 7100 MW. Right one is 2045 progress goal at 16%.

Energy storage is one of the most important tools in California's transition to a clean and reliable electric grid. By storing electricity produced during periods of abundant renewable energy generation and delivering it when demand remains high, battery storage allows clean energy to serve a larger share of California's electricity needs throughout the day and into the evening hours. 

California has built one of the largest battery storage fleets in the world. Battery storage capacity has grown from less than 700 megawatts (MW) at the beginning of 2019 to more than 21,000 MW by mid-2026. This rapid growth is helping transform how the grid operates by reducing reliance on fossil fuel generation, increasing grid flexibility and reliability, and supporting the integration of renewable energy resources. 

This dashboard presents statewide data on residential, commercial, and utility-scale energy storage installations. Residential and commercial installations are smaller behind-the-meter systems installed on homes and business throughout California. Utility-scale systems are grid-connected resources, most of which are located in California. The statewide total also includes utility-scale battery resources located in neighboring states that serve customers on the California Independent System Operator (CAISO) grid. Data was last updated June 15, 2026.  

The dashboard is best viewed from a computer.  Visit Tableau for the full page layout of dashboard or download data.

CAISO BESS: A Battery Energy Storage System (BESS) managed by the California Independent System Operator (CAISO). It stores and releases electricity to help balance supply and demand, stabilize the grid, and support renewable energy use in California.

CAISO Hybrid: A hybrid energy system managed by the CAISO that combines different types of energy resources, like batteries and renewable generation sources, to improve grid reliability and efficiency.

CAISO-OOS BESS: A CAISO BESS system located outside of the state of California.

CAISO-OOS Hybrid: A CAISO Hybrid system located outside of the state of California.

Energy Storage - a commercially available technology that is capable of absorbing energy, storing it for a period of time, and thereafter dispatching the energy.

Kilowatt - a measure of 1,000 watts of electrical power.

Megawatt - a unit of power equal to one million watts, especially as a measure of the output of a power station.

Other: A combination of energy storage resources from different public utilities that are not managed by the CAISO.

Planned CAISO: Energy storage resources that are identified in the CAISO interconnection queue that are scheduled to be added to the grid in the future but are not yet active.

Beginning with the June 2026 update, the statewide battery storage total displayed on the dashboard includes utility-scale battery resources located outside California that serve customers on the CAISO grid. These resources were previously included in the dashboard dataset and could be viewed through searches and filters; however, they were not included in the statewide total displayed on the landing page. This change provides a more complete accounting of battery storage resources supporting California's electric grid. 

Annual totals in this update differ somewhat from previous updates due to ongoing refinement of the data collection and verification process. 

Data in this dashboard is obtained through a survey of all utilities in California and is current as of June 15, 2026. The dataset will be updated semi-annually upon completion of each survey.

The use of the terms megawatts and kilowatts as descriptive of battery energy storage is to effectively convey the instantaneous power contribution of battery storage as comparable to the power produced by grid-level generators. We recognize that energy capacity in the context of energy storage typically refers to the total energy a battery can hold in watt-hours, kilowatt-hours, megawatt-hours, etc. However, for statewide planning and reliability purposes, understanding the peak power capability of battery energy storage systems allows for the integration of data with the nameplate capacity of traditional power generation units serving the grid. It is in this context that battery systems are able to be effectively compared for their ability to serve the grid over short periods of time, typically two to four hours per day depending upon system conditions.

Storage systems have capacities reported as low as five kilowatts, and some totals are reported to the nearest megawatt. This might cause some small rounding errors.

Utility data on installations of energy storage systems may not be available for all zip codes. Due to variations in local permitting regulations, not all utilities reported energy storage systems as separately identifiable from a co-located solar photovoltaic system.

California legislation under AB 2514 (Skinner, Chapter 469, Statutes of 2010) encourages utilities to incorporate energy storage into the electricity grid. Energy storage can provide a multitude of benefits to California, including supporting the integration of greater amounts of renewable energy into the electric grid, deferring the need for new fossil-fueled power plants and transmission and distribution infrastructure, and reducing dependence on fossil fuel generation to meet peak loads.

California legislation under SB 846 (Dodd, Chapter 239, Statutes of 2022) requires the CEC to expand the energy almanac report to include storage resources that serve wholesale load. SB 846 also requires the CEC to report on energy resources that serve load in the Independent Systems Operator system. This dashboard meets both of these requirements.

For more information:

Citing​
Please cite use of these data and images. California Energy Commission [Year]. California Energy Commission California Energy Storage System Survey. Data last updated [insert date last updated]. Retrieved [insert date retrieved] from https://tableau.cnra.ca.gov/t/CNRA_CEC_PUBLIC/views/EnergyStorageDashbo…

Contact​

Michael Nyberg, Energy Assessments Division, Data Integration Branch | qfergen@energy.ca.gov | 916-931-9477