Battery Storage by State 2026
By Axis Intelligence Research
Co-author: Aidan Jad | Last updated: August 14, 2026 | License: CC BY 4.0
Four states hold 87.1% of America’s utility-scale battery storage. Twenty-five hold 112 megawatts between them — less than a single Texas project coming online this year. According to Axis Intelligence Research, the state that leads the country on storage as a share of its own generating fleet is not California or Texas. It is Hawaii.
Quick Answer
California leads all states with 11,717 MW of utility-scale battery storage net summer capacity, followed by Texas at 7,905 MW, Arizona at 2,121 MW and Nevada at 1,109 MW, according to the U.S. Energy Information Administration’s State Energy Data System for 2024. Those four states are the only ones above 1 GW. Nationally, operational capacity reached 43.6 GW at the end of 2025 and roughly 52 GW by June 2026. Axis Intelligence Research calculates that batteries account for 2.20% of total U.S. generating capacity — but 12.85% of Hawaii’s.
Key Findings
- California holds 11,717 MW of utility-scale battery storage net summer capacity, 43.4% of the U.S. total, according to the EIA’s State Energy Data System 2024.
- According to Axis Intelligence Research, Hawaii ranks first among all states on the Axis Storage Penetration Index at 12.85%, ahead of California at 12.11%, despite holding just 1.6% of national battery capacity.
- U.S. utility-scale battery storage capacity grew at an average annual rate of 70% over the last three years, reaching roughly 52 GW by June 2026, according to the EIA.
- According to Axis Intelligence Research, Texas plans to add 1.63 times its entire installed battery fleet in a single year, based on 12,900 MW planned for 2026 against 7,905 MW installed at the end of 2024.
- Roughly 2,000 MW of the battery capacity serving California sits physically in Nevada and Arizona, which Axis Intelligence Research calculates as 9.5% of the state’s fleet counted outside its own borders, according to California Energy Commission data.
Source: Axis Intelligence Research — CC BY 4.0
Which States Have the Most Battery Storage?
The concentration is extreme and it is getting more extreme, not less.
The most complete state-level accounting available from a single primary table is the EIA’s State Energy Data System, Table F52, which reports electric net summer capacity by energy source for every state at the end of 2024. It puts national battery storage at 27,020 MW against 1,228,843 MW of total generating capacity. Four states clear 1,000 MW. Thirty-five states and the District of Columbia sit below 100 MW. Nine report zero.
Battery storage net summer capacity by state, top 15
| Rank | State | Battery capacity (MW) | Share of U.S. total | Total state capacity (MW) | Source |
|---|---|---|---|---|---|
| 1 | California | 11,717 | 43.36% | 96,773 | EIA SEDS 2024 |
| 2 | Texas | 7,905 | 29.26% | 168,317 | EIA SEDS 2024 |
| 3 | Arizona | 2,121 | 7.85% | 32,877 | EIA SEDS 2024 |
| 4 | Nevada | 1,109 | 4.10% | 16,725 | EIA SEDS 2024 |
| 5 | New Mexico | 689 | 2.55% | 11,887 | EIA SEDS 2024 |
| 6 | Florida | 576 | 2.13% | 72,012 | EIA SEDS 2024 |
| 7 | Hawaii | 433 | 1.60% | 3,369 | EIA SEDS 2024 |
| 8 | Colorado | 346 | 1.28% | 19,817 | EIA SEDS 2024 |
| 9 | Oregon | 322 | 1.19% | 17,692 | EIA SEDS 2024 |
| 10 | Massachusetts | 306 | 1.13% | 11,505 | EIA SEDS 2024 |
| 11 | New York | 218 | 0.81% | 41,286 | EIA SEDS 2024 |
| 12 | Georgia | 146 | 0.54% | 39,746 | EIA SEDS 2024 |
| 13 | North Carolina | 140 | 0.52% | 36,337 | EIA SEDS 2024 |
| 14 | Alaska | 132 | 0.49% | 2,853 | EIA SEDS 2024 |
| 15 | New Jersey | 110 | 0.41% | 16,606 | EIA SEDS 2024 |
| — | United States | 27,020 | 100% | 1,228,843 | EIA SEDS 2024 |
Shares are calculated by Axis Intelligence Research from EIA state figures. The full 51-row table, including every state at zero, ships in the accompanying CSV.
Capacity concentration, end of 2024
| Grouping | Combined capacity (MW) | Share of U.S. total | Source |
|---|---|---|---|
| Top 2 states (CA, TX) | 19,622 | 72.6% | Axis Intelligence Research from EIA SEDS 2024 |
| Top 3 states | 21,743 | 80.5% | Axis Intelligence Research from EIA SEDS 2024 |
| Top 5 states | 23,541 | 87.1% | Axis Intelligence Research from EIA SEDS 2024 |
| Top 10 states | 25,524 | 94.5% | Axis Intelligence Research from EIA SEDS 2024 |
| Bottom 25 states and DC | 112 | 0.4% | Axis Intelligence Research from EIA SEDS 2024 |
That last row is the one worth sitting with. The 25 lowest-ranked jurisdictions in the country hold 112 MW of battery storage between them — less than the 418 MW attached to a single solar project scheduled to energize in Navarro County, Texas this year.
Aidan Jad: Two states holding 72.6% of a national fleet is not a policy map, it is an interconnection map with a land-cost overlay. ERCOT and CAISO are the two large markets where a developer can get a study result, a network upgrade estimate and a signed agreement inside something resembling a financing window. Everywhere else, the queue position is the project risk. When people describe storage as politically polarized, they are reading the outcome backwards: the states that build are the states where the process terminates.
Which State Leads on Battery Storage Penetration?
Raw megawatts answer a question nobody in grid operations actually asks. A gigawatt of storage on a 168 GW system does something structurally different from a gigawatt on a 3 GW island system. What matters operationally is how much of a state’s generating fleet is storage.
Nobody publishes that ranking. So we built it.
Axis original metric: the Storage Penetration Index (SPI)
SPI — Storage Penetration Index. The share of a state’s total electric generating capacity that is battery storage.
Formula: SPI = state battery storage net summer capacity (MW) ÷ state total net summer generating capacity (MW) × 100
Inputs: Both values come from a single primary table — EIA, State Energy Data System 2024, Table F52, electric net summer capacity by state, total across all sectors, at end of 2024. Using one table for numerator and denominator means the survey boundary, the vintage and the capacity definition are identical on both sides of the ratio.
Baseline reading, United States: 2.20% (27,020 MW ÷ 1,228,843 MW).
Interpretation. SPI measures structural storage intensity, not ambition or size. A high reading means storage has become a material share of what a state can dispatch. A low reading on a large fleet means the state has generation but has not built the shifting layer that variable generation needs.
Axis Storage Penetration Index, top 12 states
| SPI rank | State | SPI (%) | Battery (MW) | Rank by raw MW | Source |
|---|---|---|---|---|---|
| 1 | Hawaii | 12.85 | 433 | 7 | Axis Intelligence Research from EIA SEDS 2024 |
| 2 | California | 12.11 | 11,717 | 1 | Axis Intelligence Research from EIA SEDS 2024 |
| 3 | Nevada | 6.63 | 1,109 | 4 | Axis Intelligence Research from EIA SEDS 2024 |
| 4 | Arizona | 6.45 | 2,121 | 3 | Axis Intelligence Research from EIA SEDS 2024 |
| 5 | New Mexico | 5.80 | 689 | 5 | Axis Intelligence Research from EIA SEDS 2024 |
| 6 | Texas | 4.70 | 7,905 | 2 | Axis Intelligence Research from EIA SEDS 2024 |
| 7 | Alaska | 4.63 | 132 | 14 | Axis Intelligence Research from EIA SEDS 2024 |
| 8 | Massachusetts | 2.66 | 306 | 10 | Axis Intelligence Research from EIA SEDS 2024 |
| 9 | Vermont | 2.43 | 21 | 28 | Axis Intelligence Research from EIA SEDS 2024 |
| 10 | Oregon | 1.82 | 322 | 9 | Axis Intelligence Research from EIA SEDS 2024 |
| 11 | Colorado | 1.75 | 346 | 8 | Axis Intelligence Research from EIA SEDS 2024 |
| 12 | Maine | 1.11 | 62 | 20 | Axis Intelligence Research from EIA SEDS 2024 |
The reordering is the finding. Hawaii holds 3.7% of California’s battery megawatts and outranks it. Texas drops from second on raw capacity to sixth on penetration, because 7,905 MW sits on the largest generating fleet in the country — 168,317 MW, more than any other state by a wide margin. Alaska, with 132 MW, outranks every state east of the Rockies.
Three states change character entirely under this lens. Vermont, at 21 MW, ranks ninth. Massachusetts, eighth. Neither appears in any conventional storage ranking, and both have built storage that is material relative to what they operate.
Scope of the index. SPI counts utility-scale units of 1 MW and above as captured in EIA’s generator surveys, so behind-the-meter residential and commercial systems fall outside it — a real omission in states such as California and Hawaii where distributed storage is substantial. It measures power capacity, not energy capacity, so a four-hour fleet and a one-hour fleet of the same nameplate read identically. And it is a capacity ratio, not a reliability measure: it does not tell you whether a state’s storage is sited where the grid is constrained. Read it as a structural indicator of how far storage has penetrated a state’s dispatchable mix, and pair it with the duration data below before drawing operational conclusions.
Aidan Jad: Hawaii at the top is not a curiosity, it is the clearest case in the dataset of storage doing the job it exists to do. An island system has no neighbouring balancing area to lean on, imports nothing across a tie line, and burns expensive liquid fuel when the sun goes down. That combination makes the arithmetic on a battery work at a penetration level the mainland will not reach for a decade. Texas at 4.70 is the mirror image: enormous absolute build, sitting on a fleet so large that the ratio stays modest even after the biggest storage construction program in the country.
How Fast Is U.S. Battery Storage Growing?
Fast enough that any state ranking carries a shelf life measured in months.
Utility-scale battery capacity grew at an average annual rate of 70% over the last three years, according to the EIA’s August 2026 analysis of its Preliminary Monthly Electric Generator Inventory. The fleet closed 2025 at 43.6 GW. Operators added another 8.3 GW in the first six months of 2026, taking nameplate capacity to roughly 52 GW by June.
U.S. utility-scale battery storage, operational and planned
| Period | Capacity or additions | Status | Source |
|---|---|---|---|
| End of 2024 | 27,020 MW | Operational (net summer) | EIA SEDS 2024 |
| End of 2025 | 43,600 MW | Operational | EIA (Aug 2026) |
| Jan–Jun 2026 | +8,300 MW | Added | EIA (Aug 2026) |
| June 2026 | ~52,000 MW | Operational (nameplate) | EIA (Aug 2026) |
| Jul–Dec 2026 | +14,000 MW | Planned | EIA (Aug 2026) |
| 2027 | +26,000 MW | Planned | EIA (Aug 2026) |
| 2028 | +14,000 MW | Planned | EIA (Aug 2026) |
Note that the end-2024 and end-2025 figures use net summer capacity and nameplate capacity respectively, which are not identical measures; the growth direction is unambiguous, the precise increment between those two rows is not.
Two years of that trajectory nearly doubles the base. The fleet at June 2026 is 1.92 times what it was 18 months earlier.
Which States Are Adding the Most Battery Storage in 2026?
The build is even more concentrated than the installed base.
Developers plan 24 GW of utility-scale battery storage for 2026, up from a record 15 GW added in 2025, according to the EIA’s February 2026 analysis of planned capacity additions. Battery storage makes up 28% of the 86 GW of total planned utility-scale additions. Three states account for about 80% of the storage: Texas at 12.9 GW, California at 3.4 GW, Arizona at 3.2 GW.
Planned 2026 additions against installed base
| State | Planned 2026 (MW) | Share of U.S. 2026 additions | Installed end-2024 (MW) | Build-to-base ratio | Source |
|---|---|---|---|---|---|
| Texas | 12,900 | 53% | 7,905 | 1.63× | Axis Intelligence Research from EIA |
| Arizona | 3,200 | 13% | 2,121 | 1.51× | Axis Intelligence Research from EIA |
| California | 3,400 | 14% | 11,717 | 0.29× | Axis Intelligence Research from EIA |
Formula: build-to-base ratio = planned 2026 utility-scale battery additions ÷ installed battery net summer capacity at end-2024. Inputs: EIA Preliminary Monthly Electric Generator Inventory, December 2025 data, published February 2026; EIA SEDS 2024 Table F52.
According to Axis Intelligence Research, Texas is scheduled to add 1.63 times its entire existing battery fleet inside twelve months, and Arizona 1.51 times. California, working from a much larger base, adds 0.29 times its fleet.
That ratio is the single best predictor of which state tops the raw-capacity ranking next. Texas at 7,905 MW plus 12,900 MW planned overtakes California at 11,717 MW plus 3,400 MW, if both build to plan. Developer-reported plans slip routinely, so treat the crossover as conditional rather than scheduled.
Largest battery projects due online in 2026
| Project | Location | Battery capacity (MW) | Source |
|---|---|---|---|
| Lunis Creek BESS | Jackson, Texas | 621 | EIA (Feb 2026) |
| Clear Fork Creek Solar and BESS SLF | Wilson, Texas | 600 | EIA (Feb 2026) |
| Bellefield 2 Solar & Energy Storage Farm | Kern County, California | 500 | EIA (Feb 2026) |
| Tehuacana Creek 1 Solar and BESS | Navarro County, Texas | 418 | EIA (Feb 2026) |
Aidan Jad: The build-to-base ratio deserves more attention than the megawatt league table, because it tells you where the operating experience is about to change faster than the operators can absorb it. A market adding 1.63 times its fleet in a year is commissioning assets faster than it can accumulate cycling history on the ones already running. Arizona is in the same position at 1.51. California at 0.29 is doing something categorically different — refining a fleet it has already learned to dispatch. Those are different engineering problems wearing the same headline.
Why Do State Battery Storage Numbers Disagree?
Because state lines and grid boundaries are not the same thing, and storage is the technology where that gap is widest.
The California Energy Commission reported on August 7, 2026 that battery resources serving the state now exceed 21,000 MW, at 21,112 MW total. The EIA’s state table puts California at 11,717 MW. Both are correct. They count different things.
California battery capacity by counting basis
| Component | Capacity (MW) | Physically located in California | Source |
|---|---|---|---|
| Utility-scale systems in California (310 systems) | ~16,000 | Yes | CEC (Aug 2026) |
| Utility-scale systems in Nevada and Arizona | ~2,000 | No | CEC (Aug 2026) |
| Distributed systems (300,000+ installations) | ~3,000 | Yes | CEC (Aug 2026) |
| Total serving Californians | 21,112 | — | CEC (Aug 2026) |
Three things separate the two figures. The CEC count is 20 months more recent. It includes roughly 3,000 MW of behind-the-meter systems that EIA’s utility-scale survey does not capture. And it includes about 2,000 MW of utility-scale batteries that are physically in Nevada and Arizona but serve the CAISO grid, which covers about 80% of Californians.
According to Axis Intelligence Research, 9.5% of the battery capacity serving California sits outside California’s borders.
Formula: out-of-state siting share = out-of-state utility-scale battery capacity serving the state ÷ total battery capacity serving the state × 100. Inputs: 2,000 MW ÷ 21,112 MW, both from the California Energy Commission, August 7, 2026.
This is not a rounding issue. It means every by-state storage table in circulation — including ours — assigns capacity to the state hosting the concrete pad rather than the load it firms. Nevada’s SPI of 6.63 and Arizona’s 6.45 are partly a Californian procurement decision expressed in another state’s statistics. Any analyst comparing storage-to-load ratios across the Desert Southwest needs to know that before drawing a conclusion, and almost none of the published comparisons say so.
Duration compounds the problem. The CEC notes that while Texas has a similar amount of total installed capacity, Texas systems are typically designed for two hours or less, whereas the California fleet is dominated by four-hour systems and can therefore deliver stored energy for roughly twice as long. Two fleets of matched nameplate power are not matched assets, and Axis Intelligence Research does not merge them into a single national duration figure, because averaging a two-hour arbitrage fleet with a four-hour resource-adequacy fleet produces a number that describes neither.
Aidan Jad: This is the part that gets lost every time a storage ranking goes around. A megawatt in ERCOT earns on energy and ancillaries and is sized to catch the price spike, so it comes in short. A megawatt in CAISO is sized against a four-hour resource adequacy requirement, so it comes in long. Same nameplate, different machine, different cost per unit of energy delivered. Rank states on power capacity and you have ranked their procurement rules, not their storage.
Which States Have Battery Storage Targets?
The gap between statutory targets and installed steel is the most decision-relevant number on this page for anyone siting a project outside the Southwest.
New York is the clearest case. The Public Service Commission’s June 2024 order set a state energy storage target of 6,000 MW by 2030, per NYSERDA’s 2024 Energy Storage Order Overview, expanding on the existing 3 GW Climate Act goal. The Department of Public Service describes that target as approximately 20% of the state’s peak electricity load.
New York 2030 storage target by segment
| Segment | Target (MW) | Source |
|---|---|---|
| Bulk (wholesale, NYISO-interconnected) | 3,000 | NYSERDA (2024 Order) |
| Retail distributed (commercial, community) | 1,500 | NYSERDA (2024 Order) |
| Residential | 200 | NYSERDA (2024 Order) |
| Incremental procurement authorized | 4,700 | NYSERDA (2024 Order) |
| Total 2030 target | 6,000 | NYSERDA (2024 Order) |
New York held 218 MW of utility-scale battery storage at the end of 2024. According to Axis Intelligence Research, that is 3.6% of the 6,000 MW target, with roughly six years to close it.
The comparison is not apples to apples and we will say so rather than bury it: the 6,000 MW target spans bulk, retail and residential segments, while the 218 MW numerator counts only utility-scale units of 1 MW and above. The bulk segment alone is 3,000 MW, and against that narrower denominator New York’s utility-scale fleet stands at 7.3%. Either way the required build rate is steep, and it runs through NYISO zones G–K, where the order directs at least 35% of procured capacity and where siting is hardest.
California’s target arithmetic runs the other direction. The CEC estimates more than 52,000 MW of battery and long-duration storage will be needed by 2045 and reports the state 41% of the way there. A state that has built 21,112 MW needs roughly 31,000 MW more over nineteen years. New York needs 5,782 MW over six.
What Does the State Data Mean for Data Center Siting?
Storage and load growth have started arriving in the same counties, and the state distribution above is why that matters.
The states where a developer can pair generation with multi-hour storage and reach commercial operation quickly are the same states carrying the storage fleet: Texas, Arizona, Nevada, New Mexico. Those four hold 11,824 MW between them, and Texas and Arizona are together adding 16,100 MW more this year. That is not a coincidence of climate. It is the same permitting-and-interconnection profile that makes a large flexible load buildable, expressed twice.
California illustrates the constraint from the other side. It has the deepest fleet, the longest durations and the accelerated permitting pathway — the CEC’s Opt-In Certification Program approved 1,850 MW of battery storage in the past year with more than 3,000 MW in the queue — and it still exported roughly 2,000 MW of its own utility-scale siting to Nevada and Arizona.
The demand side of this convergence is documented in our AI data center energy consumption statistics, and the capital flows behind it in our AI data center statistics. For national capacity, cost and interconnection-queue figures, our battery storage statistics report is the pillar this page sits under. The competing firm-capacity option is covered in our nuclear energy statistics report, and the electricity demand trajectory in our data center electricity demand tracker.
Aidan Jad: A siting team reading this table should not read it as “go where the batteries are.” Installed storage is a lagging indicator of a permitting regime. What it actually marks is where the interconnection process resolves, where land is permittable next to existing transmission, and where a co-located generation-plus-storage package can reach commercial operation before the load is contracted. Storage shows up first because it is the fastest thing to build. The load follows the same map for the same reasons.
Methodology
Collection. Every figure in this report was retrieved from a primary source document during production on August 14, 2026. No statistic originates from model memory or from a secondary aggregator. Six source documents were fetched and read:
- U.S. Energy Information Administration, State Energy Data System 2024, Table F52: Electric net summer capacity, total (all sectors), 2024
- U.S. Energy Information Administration, Today in Energy: Battery storage capacity averaged 70% growth over the last three years, August 7, 2026, based on the Preliminary Monthly Electric Generator Inventory
- U.S. Energy Information Administration, Today in Energy: New U.S. electric generating capacity expected to reach a record high in 2026, February 20, 2026, based on the Preliminary Monthly Electric Generator Inventory, December 2025 data
- California Energy Commission, California surpasses 21,000 megawatts of battery resources supporting the state’s electric grid, August 7, 2026
- New York State Energy Research and Development Authority, 2024 Energy Storage Order Overview
- New York State Department of Public Service, PSC Approves Bulk Energy Storage Plan
Validation. The 51 state battery values and the 51 state total-capacity values were summed independently and reconciled against EIA’s published national totals. Our sums returned 27,022 MW and 1,228,847 MW against EIA’s published 27,020 MW and 1,228,843 MW, differences of 2 MW and 4 MW attributable to independent rounding in the source table. All ratios were computed twice in separate passes.
Axis-calculated figures. Four metric families in this report are calculated by Axis Intelligence Research, each with formula and inputs disclosed inline at the point of use: the Storage Penetration Index (SPI), state shares of national capacity, the build-to-base ratio for 2026 additions, and California’s out-of-state siting share. Every calculated row is flagged axis_calculated = yes in the accompanying CSV with a method note.
Source reconciliation. The EIA and the California Energy Commission report materially different figures for California battery capacity — 11,717 MW and 21,112 MW. We publish both and explain the boundary difference rather than averaging them, because the CEC figure includes behind-the-meter systems and out-of-state facilities that EIA’s utility-scale state table by construction excludes, and because the two carry vintages twenty months apart. Readers modelling state capacity should choose one basis and stay with it.
Units. Battery capacity is reported in megawatts of power capacity throughout. Energy capacity in megawatt-hours is a different measure and the two are not interchangeable; where duration matters we say so rather than converting. EIA SEDS values are net summer capacity; the June 2026 national figure is nameplate capacity, and the two definitions differ.
Scope. State-level values are end-2024, the most recent complete year in EIA’s state series; national values run to June 2026, and the two vintages should not be mixed within a single calculation. Utility-scale coverage captures units of 1 MW and above reported through EIA generator surveys, so distributed storage is excluded from all state rows. Planned 2026 additions are developer-reported intentions rather than commitments, and historical slippage between planned and realized additions is material. Capacity is assigned to the state hosting the equipment, which the California case shows can diverge from the load it serves.
About This Dataset
File: battery-storage-by-state-2026.csv
Contents: 281 observations covering battery storage net summer capacity and total generating capacity for all 50 states and the District of Columbia, the Axis Storage Penetration Index for every state, state shares of national capacity, national fleet trajectory 2024–2028, planned 2026 additions by state, project-level capacity, California capacity by counting basis, and New York’s 2030 target by segment.
Temporal coverage: 2019–2045 (observations 2019–2026; planned additions to 2028; policy targets to 2045)
Spatial coverage: United States, with all 50 states and the District of Columbia
Provenance columns: every row carries source organization, source document, source URL, retrieval date, primary-source flag, Axis-calculated flag, and a method note for calculated rows.
License: CC BY 4.0
Citation: Axis Intelligence Research, Battery Storage by State 2026, 2026, axis-intelligence.com/battery-storage-by-state/
How to Cite This Report
APA Axis Intelligence Research. (2026). Battery storage by state 2026: Capacity, rankings and the penetration gap. https://axis-intelligence.com/battery-storage-by-state/
MLA Axis Intelligence Research. “Battery Storage by State 2026: Capacity, Rankings and the Penetration Gap.” Axis Intelligence, 14 Aug. 2026, axis-intelligence.com/battery-storage-by-state/.
Chicago Axis Intelligence Research. “Battery Storage by State 2026: Capacity, Rankings and the Penetration Gap.” Axis Intelligence, August 14, 2026. https://axis-intelligence.com/battery-storage-by-state/.
Frequently Asked Questions
Which state has the most battery storage capacity?
California, with 11,717 MW of utility-scale battery storage net summer capacity at the end of 2024, or 43.4% of the U.S. total, according to the EIA’s State Energy Data System. Texas is second at 7,905 MW. On a more recent and broader basis, the California Energy Commission reported 21,112 MW of battery resources serving the state as of August 2026, a figure that includes behind-the-meter systems and out-of-state facilities.
How many states have more than 1 GW of battery storage?
Four: California, Texas, Arizona and Nevada, based on EIA end-2024 state data. Thirty-five states and the District of Columbia hold under 100 MW, and nine report none at all. The count above 1 GW rises as the 2026 build completes, with New Mexico at 689 MW the nearest to crossing.
What is the Storage Penetration Index?
The Storage Penetration Index (SPI) is a metric built by Axis Intelligence Research that expresses a state’s battery storage capacity as a percentage of its total electric generating capacity, using EIA State Energy Data System figures for both the numerator and the denominator. The U.S. baseline reading is 2.20%. Hawaii leads all states at 12.85%, ahead of California at 12.11%.
Why does Texas rank second on capacity but sixth on penetration?
Because Texas operates the largest generating fleet in the country at 168,317 MW. Its 7,905 MW of storage is a large absolute build sitting on a very large base, producing an SPI of 4.70%. California’s 11,717 MW sits on 96,773 MW, producing 12.11%. The ranking difference reflects fleet size, not storage ambition.
Which states are building the most battery storage in 2026?
Texas, California and Arizona account for about 80% of the 24 GW planned nationally, at 12.9 GW, 3.4 GW and 3.2 GW respectively, according to EIA. Measured against their existing fleets, Texas is adding 1.63 times its installed capacity and Arizona 1.51 times, while California adds 0.29 times.
Does California’s battery storage all sit inside California?
No. Roughly 2,000 MW of the 21,112 MW serving Californians is located at utility-scale facilities in Nevada and Arizona connected to the CAISO grid, according to the California Energy Commission. Axis Intelligence Research calculates that as 9.5% of the state’s fleet, which means by-state tables understate California and overstate its neighbours.
Why do California battery numbers differ between EIA and the CEC?
The two agencies count different things. EIA’s state table reports utility-scale units of 1 MW and above physically located in the state at end-2024. The CEC reports all battery resources serving Californians as of August 2026, including roughly 3,000 MW of distributed systems and about 2,000 MW sited in Nevada and Arizona. Neither figure is wrong; they answer different questions.
How much storage does New York need to hit its 2030 target?
New York’s Public Service Commission set a 6,000 MW target for 2030, split into 3,000 MW bulk, 1,500 MW retail distributed and 200 MW residential, with 4,700 MW of incremental procurement authorized. The state held 218 MW of utility-scale battery capacity at end-2024, which Axis Intelligence Research calculates at 3.6% of the full target and 7.3% of the bulk segment alone.
Are Texas and California batteries comparable on capacity alone?
Not directly. The California Energy Commission notes that Texas systems are typically designed for two hours of discharge or less, while California’s fleet is dominated by four-hour systems delivering stored energy for roughly twice as long. Comparing nameplate power capacity across the two states compares procurement rules as much as it compares hardware.
How fast is U.S. battery storage capacity growing?
At an average annual rate of 70% over the last three years, according to EIA. The fleet closed 2025 at 43.6 GW, added 8.3 GW in the first half of 2026 to reach roughly 52 GW, and operators report plans for a further 14 GW in the second half of 2026, 26 GW in 2027 and 14 GW in 2028.
Which small states punch above their weight on storage?
Hawaii ranks first nationally on SPI at 12.85% with just 433 MW, and Alaska seventh at 4.63% with 132 MW — both isolated systems with no neighbouring balancing area to lean on and expensive fuel to displace. Vermont ranks ninth at 2.43% with 21 MW, and Massachusetts eighth at 2.66%, the highest reading of any state in the eastern interconnection.