U.S. small-scale solar output rose to 92,979 GWh in a decade

California produced 34,411 GWh of small-scale solar power in 2025, 37% of the national total, and it is far from the only place where rooftop panels are doing real work. Across the United States, generation from systems smaller than 1 megawatt rose from 18,812 GWh to 92,979 GWh over the last decade, according to estimates from the U.S. Energy Information Administration.

The agency cannot simply read these numbers from meters. Utilities generally do not know how much electricity the panels on their customers' roofs produce, so the EIA surveys them for the number of systems and their combined capacity, then estimates output with tools from the National Renewable Energy Laboratory, the System Advisor Model and PVWatts. Those estimates assume tilt angles and orientations typical of California systems, applied to the other states as well. The totals are therefore a careful reconstruction, not a count of every kilowatt-hour.

Sun explains part of the map, and policy explains the rest. Texas grew from 391 GWh in 2016 to 5,408 GWh last year, and Florida from 205 GWh in 2016 to 5,198 GWh in 2025, both helped by property tax exemptions and utility programs. New York gets less sun than the leaders, yet ranks fifth thanks to capacity growth supported by technology improvements and state incentives. Arizona customers can claim a 25% state income-tax credit on rooftop systems, and the state's generation reached 5,795 GWh.

The sharpest jump came in 2022. California's Net Energy Metering 2.0 program, which paid higher compensation for power exported to the grid than its successor, the Net Billing Tariff, was available until April 2023, and every system built under it was grandfathered in. Households had a strong reason to install before the switch, and the data show it. Growth has been slower since, though still positive, with California's rooftop generation rising 8% between 2024 and 2025 mainly because capacity increased.

For a homeowner, the lesson is practical: the return on a rooftop system depends on the incentives and the export terms on offer, and the states that combine good sun with clear rules have moved the furthest. The slowdown since 2022 is the number to watch, because it shows that the growth of the last decade was not automatic. Whether the next decade matches it depends on whether programs keep making rooftop panels worth installing.