Battery storage on 37% of new U.S. residential solar in 2025

Estimated reading time: 4 minutes · Last updated: 4 October 2026

Battery storage was paired with 37% of new U.S. residential solar installations in 2025, up from 25% in 2024, Lawrence Berkeley National Laboratory reports. The lab’s annual U.S. Distributed Solar and Storage Data update covers roughly 5.3 million distributed systems installed through the end of 2025 and counts about 450,000 systems added during 2025, an amount the lab estimates represents 93% of that year’s U.S. distributed solar market. The shift reflects both a near-universal uptake in California and faster growth outside the state as changes in export compensation and time-of-use rates raise the value of storing daytime generation.

How Berkeley Lab measures attachment and what the numbers mean

Lawrence Berkeley National Laboratory’s U.S. Distributed Solar and Storage Data update counts how often installers add batteries to new solar projects; it excludes batteries installed later and standalone systems. Using that narrower measure, the lab reports a rise in the residential storage attachment rate to 37% in 2025 from 25% in 2024. The underlying dataset includes roughly 5.3 million distributed solar and solar-plus-storage systems installed through the end of 2025 and about 450,000 installations recorded in 2025, which the lab says captures an estimated 93% of the U.S. distributed solar market for the year.

Because the figure tracks batteries paired at the time of solar install, it directly reflects installer behaviour and sales packaging rather than total household battery deployment. That caveat matters when comparing attachment rates with broader measures of residential storage adoption that include retrofit and standalone batteries.

Why California led the change and why other states caught up

California accounted for much of the national increase: 74% of new residential solar systems in the state included storage in 2025, up from 58% in 2024. The state’s shift to a Net Billing Tariff, commonly called NEM 3.0, in April 2023 reduced the value of exported solar for many hours and made storing excess generation more economically attractive to new rooftop solar customers.

Outside California the residential attachment rate rose sharply from 7% to 17% in one year. Berkeley Lab does not ascribe that jump to a single cause, but installers in multiple states are responding to similar commercial signals — weaker export compensation, growing deployment of time-of-use and demand charges, and customer interest in resilience — all of which raise the economics of pairing batteries with new arrays. The dataset highlights large increases in Arizona and Texas and continued high rates in Hawaii.

What’s changing on systems themselves and the limits of the data

While the median amount of stored energy per residential battery held at 13.5 kWh in both 2024 and 2025, the typical power those batteries can deliver rose sharply. Berkeley Lab reports median discharge capability moved from 6 kW in 2024 to 11.4 kW in 2025, a change the lab links in part to higher-discharge models such as Tesla’s Powerwall 3. That trend shifts what batteries can do for homes, enabling larger on-demand loads and faster backup performance.

The lab also notes that non-residential attachment rates remain much lower: batteries accompanied 11% of U.S. non-residential solar installs in 2025, up from 7% in 2024. And, because the dataset omits batteries added after initial solar install and standalone deployments, it understates total residential battery capacity growth measured across all installation types.

Arguments for and against continued rapid uptake

The bottom line

The Lawrence Berkeley National Laboratory data show solar-plus-storage moving from niche to mainstream in the new-install market: installers attached batteries to more than one in three new residential solar systems in 2025. California remains the single largest driver, but the doubling of attachment rates outside the state signals a broader market transition driven by rate design and consumer demand for resilience. Because the dataset measures pairing at time of install, it understates retrofit and standalone battery deployments; nonetheless, the rise in system discharge capability suggests the market is not just adding capacity but is changing what batteries can deliver to customers.

What to watch

• Watch for Lawrence Berkeley National Laboratory’s next U.S. Distributed Solar and Storage Data update; no publication date has been set.
• Watch for state utility commission rulemakings or tariff filings that alter export compensation or time-of-use rates in major rooftop markets; no specific dates have been set.