Share of operating battery power capacity, by state
This interactive map and sortable table show every utility-scale battery energy storage system (BESS) in the United States, all 1,600 grid-connected storage facilities of 1 MW or larger, color-coded by configuration: standalone (857), solar-paired (671), wind-paired (17) and power-plant-site (55). Facilities are shown across all statuses: active (1,055), standby (19), in development (483) and decommissioned (43). Together the 1,055 active systems hold about 54,201 MW (~54 GW) of power capacity, while a further 72,739 MW sits in development, more than the entire operating fleet. Energy capacity in MWh is reported by EIA only for operating and retired units, so planned projects show power capacity alone. Battery storage is the fastest-growing resource on the US grid, with roughly 80% of new capacity in Texas, California and Arizona.
Storage is concentrated in three states, and most of it runs for four hours. Texas, California and Arizona hold 75.63% of US operating battery power capacity between them, and Texas has now passed California to lead the country, at 18,262 MW against 16,094 MW. Duration is the more revealing measure: 43.76% of the fleet’s power capacity sits in systems rated at about four hours, the configuration that California resource-adequacy rules effectively standardised and that developers have built to ever since. A further 30.20% is under two hours, mostly older systems built for frequency response rather than energy shifting. Only 3.46% runs beyond four hours, which is the gap that long-duration storage is meant to fill.
Sources, basis and how the totals reconcile
Source. Both charts are computed from this page’s own dataset, which is built directly from the U.S. Energy Information Administration’s Preliminary Monthly Electric Generator Inventory (Form EIA-860M), August 2026 release. Reconciled against that release: only Batteries generators are counted, so hybrid sites exclude their solar, wind and thermal units; energy capacity in MWh is reported by EIA only on the Operating and Retired sheets, so planned projects show power capacity alone; status follows the parenthesised EIA status code, so (SB), (OA) and (OS) are standby rather than active; and 134 projects appearing only on EIA’s Canceled or Postponed sheet, totalling about 14,900 MW, were removed because they were never built. A verification pass in August 2026 re-examined the largest projects EIA had moved to its Canceled or Postponed sheet. That sheet carries no status field, so EIA does not distinguish a cancelled project from a postponed one. Each was checked against developer statements, interconnection-queue positions and state siting records: those found to be postponed are carried here as in development, with the reason stated in the plant summary; those confirmed cancelled, and those whose status could not be established from the public record, are excluded. EIA marks monthly inventory capacities as preliminary and subject to revision.
Basis. Both charts cover the 1,022 operating systems only, and exclude the 444 in development, 19 on standby and 180 retired or cancelled. Shares are of nameplate power capacity in megawatts, which sums to 51,584 MW on both charts, so each reconciles exactly. Percentages use largest-remainder rounding at two decimal places so each chart adds to 100.00%.
Duration. Duration is each system’s reported energy capacity in megawatt-hours divided by its power capacity in megawatts, giving the hours it can sustain full output. EIA reports no energy capacity for a small number of sites totalling 333 MW, which are shown as a separate slice rather than dropped or assumed. The fleet holds 145,226 MWh against 51,584 MW, a weighted mean of 2.82 hours.
Why these two measures. Batteries shift electricity rather than producing it, so the generation mix shown on the other pages of this site has no equivalent here, and battery storage is deliberately excluded from those capacity charts for the same reason. Location and duration are the two properties that determine what a storage fleet can actually do for a grid: where the power can be delivered, and for how long.
Share of operating battery power capacity, by duration at full output
| # | Plant | Configuration | State | Nearest city | Operator / Developer | Status | Capacity | Online |
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US battery capacity has grown from almost nothing in 2020 to tens of gigawatts today, with more than 40 GW added in five years. EIA expects roughly 24 GW more in 2026 alone, more than any other resource except solar.
About 80% of new 2026 battery capacity is concentrated in three states: Texas (roughly 12.9 GW), California (3.4 GW) and Arizona (3.2 GW). Both ERCOT and CAISO now operate well over 14 GW of storage each.
Batteries do not produce energy; they shift it, charging when power is cheap or plentiful and discharging at peak. That makes capacity (MW) only half the story; duration (MWh) matters just as much, and most US systems store two to four hours.
Grid-connected battery energy storage systems (BESS) of 1 MW or larger, matching the EIA reporting threshold used across this site. Behind-the-meter home and small commercial batteries are excluded, as are pumped-storage hydro plants, which are hydroelectric facilities and appear on the Hydroelectric page. Flywheel storage is also excluded: EIA files six flywheel plants, about 50 MW in total including Beacon Power’s 20 MW sites at Stephentown, New York and Hazle, Pennsylvania, under the same energy source code as batteries, but they store energy mechanically rather than electrochemically.
Standalone BESS is a merchant or utility battery on its own site. Solar + Storage and Wind + Storage are batteries co-located with, and usually sharing an interconnection with, a renewable plant. Power Plant Site covers batteries installed at an existing or retired thermal generating station, often reusing its grid connection.
Both are shown. MW is the power a battery can deliver at once and MWh is how much energy it holds; the ratio of the two gives its duration. The map, table and capacity column use MW for consistency with the other pages on this site, and each facility’s profile gives its energy capacity in MWh and the resulting duration where EIA reports one. Across the operating fleet that works out at roughly 144,500 MWh against 52,800 MW, just under three hours at full output, though individual systems range from under an hour to eight hours or more.
Yes, though it is rare. The clearest example is Vistra’s Moss Landing site in California, where the January 2025 fire destroyed the 300 MW array; Vistra moved both the 300 MW and 100 MW units to its Asset Closure segment and confirmed neither will return to service.
It is complete for the source. Every battery facility of 1 MW or larger appears here, 1,659 plants across all 50 states, covering the operating, planned, retired and cancelled inventories, plus a small number of announced projects that developers have made public but which have not yet been filed with EIA. Because EIA aggregates to the plant level, a site with several battery units appears as one entry with its units combined.
It reflects EIA Form EIA-860M (Preliminary Monthly Electric Generator Inventory) through August 2026, supplemented by company announcements for a few projects not yet filed with EIA. EIA notes that preliminary monthly capacities are estimates and may be revised.
Battery storage is the newest layer on the US grid and the fastest growing. Where the other maps on this website show where fuel is burned or where wind and sun are strongest, this one shows where the grid needs timing, the ability to move power by a few hours. That is why the dots cluster so tightly in Texas, California and Arizona: all three added enormous amounts of solar and wind, and all three discovered that surplus midday power is worth far more if it can be held until evening.
The configuration split tells the rest of the story. Early storage was mostly bolted onto solar farms, sharing their land and interconnection. The centre of gravity has since moved to standalone merchant batteries that sit on their own sites and earn revenue purely by arbitraging price and selling grid services. A third pattern is quietly reusing the fossil fleet: batteries built at existing or retired thermal plants, inheriting a grid connection that once carried coal, oil or gas power, using the same substations, now moving stored electrons. As batteries take over the reserve role, some of the standby capacity described in The Power Plants That Almost Never Run is being displaced.