U.S. Small-Scale Solar Generation Quadrupled

Estimated reading time: 5 minutes · Last updated: 19 October 2026

U.S. generation from small-scale solar photovoltaic systems — systems smaller than 1 megawatt — rose sharply over the last decade, from 18,812 gigawatthours (GWh) to 92,979 GWh, the U.S. Energy Information Administration reported on October 16, 2026, as first reported by the U.S. Energy Information Administration. That increase represents roughly a 395% rise in output and concentrated growth in four states: California, Arizona, Texas and Florida. California alone produced 34,411 GWh in 2025, about 37% of U.S. small-scale solar generation, while state incentives, legacy net‑metering rules and capacity additions explain much of the regional pattern.

How much rooftop solar the U.S. now generates

EIA estimates put U.S. small-scale solar generation at 92,979 GWh in 2025, up from 18,812 GWh about ten years earlier. That increase is the result of both new capacity and, in some states, policy designs that rewarded early installations. Using the timeframe EIA analysed, the national year‑over‑year change peaked in 2022 when total generation rose 25% compared with 2021; since 2022 the annual growth rate has slowed. The agency defines small-scale systems as those smaller than 1 megawatt of capacity, a threshold used in its utility surveys and modelling inputs.

Those national totals mask concentration: California produced 34,411 GWh in 2025, or 37% of small-scale output. Arizona, Texas and Florida each contributed materially to the national total: Arizona supplied 5,795 GWh in 2025 (just over 6% of the U.S. total), while Texas and Florida reached 5,408 GWh and 5,198 GWh, respectively.

State patterns and the role of incentives and policy

Regional differences in solar resource quality combine with incentives and rules to shape where rooftop solar expanded fastest. California’s legacy net‑metering framework helped concentrate installations before later rate designs took effect: Net Energy Metering 2.0 was available through April 2023 and systems built under it were grandfathered when the state moved to the Net Billing Tariff, often called NEM 3.0. Between 2024 and 2025 California’s small-scale capacity rose from 18 gigawatts to 20 gigawatts, and rooftop generation grew 8% over that year.

Arizona’s growth has been supported by a 25% state income‑tax credit and other incentives; the state’s small-scale generation grew 22% between 2022 and 2023 and 6% between 2024 and 2025. Texas and Florida rely more on property tax exemptions and varied utility programs, explaining how Texas moved from 391 GWh in 2016 to 5,408 GWh in 2025 and Florida from 205 GWh in 2016 to 5,198 GWh in 2025. New York ranks fifth in rooftop generation largely because state incentives and capacity additions offset lower solar irradiance.

How EIA estimates rooftop generation and its limits

EIA derives generation estimates from utility surveys of customers and aggregated capacity, then models output because utilities often do not measure on‑site generation directly. The agency uses modelling tools from the National Renewable Energy Laboratory, including the System Advisor Model (SAM) and PVWatts, and it applies representative tilt angles and orientations for small-scale arrays when calculating likely generation.

That method produces a consistent national time series but carries model uncertainty: inputs such as typical tilt, orientation and system performance determine the results, and EIA notes those assumptions explicitly. Where state programs change compensation or accelerate installations, the combination of capacity counts and modelling can show sharp year‑to‑year swings, as seen in 2022 when record capacity additions translated into the 25% jump in estimated generation.

What the changing growth rate means for grid planning

The slowdown in growth since 2022 suggests the market is shifting from a phase of rapid capacity expansion to one shaped more by policy adjustments, interconnection processes and incremental deployment. Even with a lower growth rate, small-scale solar added materially to supply: California’s 20 gigawatts of small-scale capacity in 2025 produced 34,411 GWh that year. Planners and utilities must therefore account for distributed generation when forecasting peak demand and distribution system flows.

Because EIA’s estimates depend on capacity tallies and modelled generation, near-term policy moves — changes to net‑metering rules, incentive sunsets or new tax credits — can alter both the amount of rooftop capacity installed and its measured generation. The data to date show rapid increases in several Sun Belt states and strong policy-driven uptake in states with lower irradiance, such as New York, New Jersey, Massachusetts and Illinois.

Outlook — forces that could raise or slow small-scale generation

The bottom line

EIA’s numbers make clear that U.S. small‑scale solar moved from a niche to a substantial contributor to distributed generation over the past decade: 18,812 GWh became 92,979 GWh, concentrated in a handful of states led by California’s 34,411 GWh in 2025. The 2022 capacity surge and subsequent moderation show how incentives, net‑metering designs and interconnection processes drive year‑to‑year swings. For planners and policymakers, the central task is translating these distributed resources into predictable flows on distribution systems while recognising how state policy choices — tax credits, net‑metering and property tax treatments — continue to shape where rooftop solar grows next.

What to watch

• Watch for EIA’s next small‑scale solar update; no date has been set.
• Watch for state-level adjustments to compensation or incentive programmes in California; no date has been set.
• Watch for changes to property- or income‑tax incentives in Arizona, Texas or Florida that could alter installation economics; no date has been set.