Renewables
US rooftop solar generation quadruples over ten years
Small-scale photovoltaic systems across the United States experienced rapid growth over the past decade, driven by state-level incentives and policy shifts.
Key points
- Small-scale solar output expanded from 18,812 gigawatthours to 92,979 gigawatthours over the decade.
- California, Arizona, Texas, and Florida lead the nation in rooftop solar generation.
- New York ranks fifth despite lower regional solar irradiance due to supportive state programs.
What happened
According to CleanTechnica, electricity generation from small-scale solar photovoltaic systems with capacities under 1 megawatt quadrupled over the past ten years. Output expanded from 18,812 gigawatthours to 92,979 gigawatthours. The most substantial year-over-year jump occurred in 2022, when generation climbed by 25 percent alongside record capacity additions.
California remained the largest producer, generating 34,411 gigawatthours in 2025, which represented 37 percent of the national total. Capacity in the state rose from 18 gigawatts in 2024 to 20 gigawatts the following year. Policy frameworks influenced this expansion, including the transition from the Net Energy Metering 2.0 program to the Net Billing Tariff, known as NEM 3.0.
Why it matters
Geographic distribution shows that states with high solar irradiance capture the largest shares of generation. Arizona, Texas, and Florida follow California in output volume, bolstered by regional policies such as property tax exemptions and state income-tax credits.
At the same time, regions with lower solar resources have increased their adoption. New York emerged as the fifth-largest producer nationwide, supported by technology advancements and local initiatives. Similar growth patterns appeared in New Jersey, Massachusetts, and Illinois.
What comes next
While small-scale solar output continues to rise annually, the overall rate of expansion has moderated since the peak growth observed in 2022. Because electric utilities do not directly track actual rooftop electricity production on their distribution networks, official figures rely on estimation methodologies. Agencies utilize modeling tools, including the National Renewable Energy Laboratory's System Advisor Model and PVWatts, combined with standardized tilt and orientation assumptions, to calculate aggregate generation statistics.
Original reporting
This article draws on the following reports. Read them in full on the publishers’ sites.
Context from CEII
Renewables are the fastest-growing part of the world’s energy system. The COP28 goal is to triple capacity by 2030, and solar mini-grids are the fastest route to power for millions of people without electricity.
27.8% of electricity in the world was renewable in 2021Countries in this story
Written by the CEII Desk, the Centre’s automated newsroom, from the reporting credited above and CEII’s own data. Facts are attributed to their sources; the publishers have not reviewed this article. Spotted an error? Tell our editors.
