Contents
- Residential battery storage installations statistics: U.S. residential battery system counts and capacity
- Residential battery storage installations statistics: annual solar-plus-storage attachment rates
- Residential battery storage installations statistics: California’s installed base and capacity
- Residential battery storage installations statistics: California add-on storage and interconnection
- Residential battery storage installations statistics: battery system sizing and power
- Sources
Residential battery storage installations statistics: U.S. residential battery system counts and capacity
At the end of 2023, the United States had 215,005 cumulative residential battery storage systems, according to an NREL slide compiling data from EIA sources. The same slide gives a broader national snapshot: residential applications accounted for 98% of U.S. battery systems but 9% of installed battery energy storage capacity. Those percentages describe different measures—system count and energy capacity—so they should not be read as equivalent shares of one total. Source: NREL, Spring 2024: Solar Industry Update, slide 48
| U.S. residential battery measure | Reported value | Period and unit |
|---|---|---|
| Cumulative residential systems | 215,005 | December 2023, systems |
| Share of U.S. battery system count | 98% | End of 2023 |
| Share of installed U.S. battery energy storage capacity | 9% | End of 2023 |
| Cumulative residential power capacity | 1,488 MW | December 2023 |
| Residential energy capacity shown alongside power | 1,671 MWh | December 2023 |
The capacity figures distinguish power from stored energy: 1,488 MW is power capacity, while 1,671 MWh is energy capacity. NREL’s figure reports the count and both capacity measures in its end-of-2023 breakdown. These are cumulative installations, not the number installed during 2023 alone. The cited NREL slide is a secondary compilation that references EIA’s Electric Power Monthly and EIA forms 023, 826, 860, and 861; it is not a direct extraction from an EIA spreadsheet. Source: NREL, Spring 2024: Solar Industry Update, slide 48
Residential battery storage installations statistics: annual solar-plus-storage attachment rates
An attachment rate measures the share of new photovoltaic (PV) systems paired with storage. Berkeley Lab reports that the U.S. residential rate rose from 25% of installs in 2024 to 37% in 2025. This measure applies to new residential PV systems in each year. It does not include standalone battery installations or storage added later to an existing PV system. Source: Berkeley Lab, U.S. Distributed Solar and Storage: 2026 Data Update, p. 5
| Residential PV-plus-storage attachment measure | Rate | Scope |
|---|---|---|
| United States, 2024 installs | 25% | New residential PV systems paired with storage |
| United States, 2025 installs | 37% | New residential PV systems paired with storage |
| Hawaii, 2024 installs | 85% | New residential PV systems paired with storage |
| California, 2023 installs | 14% | New residential PV systems paired with storage |
| California, 2024 installs | 57% | New residential PV systems paired with storage |
| States other than California combined, 2024 | 8% | Residential PV systems; states combined |
| Outside Hawaii and California, 2024 | 6% | Average for new residential PV installs |
The state figures show different patterns within the same general measure. Hawaii had an 85% residential attachment rate in 2024, and Berkeley Lab’s 2025 update says that Hawaii’s rate had remained about 85% since 2021. California’s rate increased from 14% in 2023 to 57% in 2024. Across all states other than California combined, the rate rose from 5% in 2023 to 8% in 2024; a separate Berkeley Lab summary reports an average of 6% for states outside both Hawaii and California in 2024. These groupings have different geographic scopes and are reported as such. Sources: Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, pp. 6 and 28; Berkeley Lab, U.S. Distributed Solar and Storage: 2026 Data Update, p. 5
Residential battery storage installations statistics: California’s installed base and capacity
The California Energy Commission’s (CEC) 2024 cumulative behind-the-meter (BTM) storage table reports 246,000 residential systems, 1,900 MW of power capacity, and 4,100 MWh of energy capacity. BTM refers to systems on the customer side of the electricity meter. The count, power, and energy figures describe separate dimensions of the cumulative residential installed base; they are not interchangeable measures. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, p. 10
| California residential BTM storage, cumulative in 2024 | Reported value |
|---|---|
| Systems | 246,000 |
| Power capacity | 1,900 MW |
| Energy capacity | 4,100 MWh |
CEC staff also reported 800 MW of residential storage additions statewide during 2024. That is an annual addition measured in power capacity; it is distinct from the cumulative 1,900 MW total in the table. The cumulative table and annual-additions statement therefore describe different time frames and should be kept separate. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, p. 10
Residential battery storage installations statistics: California add-on storage and interconnection
California’s BTM totals include more than storage paired with newly installed PV. CEC staff’s 2024 observations include additions to existing standalone PV systems in investor-owned utility (IOU) service territory. The presentation says data suggested 12,000 storage additions to standalone PV systems in IOU territory during 2024. A related callout reports 115 MW of storage capacity added to existing standalone PV in 2024. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, pp. 9 and 14
For the CEC’s IOU residential series of storage additions to existing standalone PV, the median storage addition was 10 kW and the median PV expansion was 4 kW. The presentation says 57% of storage additions also expanded the PV system. These are characteristics of the identified retrofit series, not statewide averages for every residential battery installation. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, p. 14
Interconnection application data for PG&E and SCE service territories show a change in the paired share over the reported quarters: paired residential applications were 11% in Q1 2023 and 77% in Q4 2024. The corresponding standalone shares shown in the chart were 89% and 23%. These are quarterly shares of residential applications in the CEC analysis, rather than cumulative installed-system shares. Separately, the CEC presentation reports an 80% residential attachment rate in December 2024 in its NBT context. These measures have different labels and scopes, so the December figure should not be substituted for the quarterly interconnection series. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, pp. 9 and 12
Residential battery storage installations statistics: battery system sizing and power
Berkeley Lab reports a median energy capacity of 13.5 kWh for residential PV-paired battery systems in its 2024 sizing sample, with most systems ranging from 10 to 20 kWh. The report notes that California accounts for about 90% of the sizing data, so the sample is disproportionately Californian. For 2025, Berkeley Lab again reports a 13.5 kWh residential median. That sizing sample is based on storage paired with PV and is primarily California, at about 80%. These medians describe the respective samples and years; they do not establish that every residential installation has that capacity. Sources: Berkeley Lab, U.S. Distributed Solar and Storage: 2025 Data Update, p. 7; Berkeley Lab, U.S. Distributed Solar and Storage: 2026 Data Update, p. 6
CEC’s model reference table illustrates why energy capacity and power rating should be reported separately. It lists the Tesla Powerwall 2 at 5.0 kW and 13.5 kWh, and the Tesla Powerwall 3 at 11.5 kW and 13.5 kWh. In these reference values, kW describes power and kWh describes energy capacity. They are model reference figures in the CEC presentation, not measured averages of California installations. Source: California Energy Commission, Historical Behind-the-Meter Distributed Generation Insights, p. 9
The available figures therefore cover several distinct views of residential storage: a U.S. cumulative system snapshot at the end of 2023, annual PV-plus-storage attachment rates, California’s cumulative BTM base and additions, retrofit and interconnection observations, and sampled system sizing. Each answers a different question, with its own geography, period, denominator, and unit.