California Reduces Natural Gas Use As Solar Generation Surges In 2025 – EIA

Electricity generation from natural gas in California has declined in recent years as solar power generation continues to rise. While natural gas still provides more electricity than any other source in the state, its share has steadily decreased, reflecting the growing contribution of solar energy. Data from the Electric Power Monthly shows that from January through August 2025, California generated 140.9 billion kilowatthours (BkWh) of electricity, which is 8 percent higher than the same period in 2020.

The growth in electricity generation in recent years has been largely driven by solar energy. Utility-scale solar power plants produced 40.3 BkWh in the first eight months of 2025, nearly double the 22.0 BkWh produced during the same period in 2020. Compared with 2024, solar generation rose 17 percent, or 5.9 BkWh, demonstrating steady annual growth. This increase in solar output is reducing reliance on natural gas, especially during the daytime when solar generation peaks.

Natural gas generation between January and August 2025 was 45.5 BkWh, which is 18 percent less than the same period in 2020. Although output had temporarily increased in 2021 due to reduced hydroelectric production caused by drought conditions, natural gas generation has declined since then. The largest year-over-year drop occurred in 2025, when natural gas output fell by 9.5 BkWh, or 17 percent, compared with 2024. In contrast, during low-water years, such as 2021, hydroelectric output fell to 10.3 BkWh, causing natural gas generation to spike to 63.5 BkWh.

The reduction in natural gas use is most noticeable during midday hours when solar generation is highest. Data from the California Independent System Operator shows that solar generation during May and June increased from 10.2 gigawatts (GW) in 2020 to 18.8 GW in 2025. In addition, energy storage is helping displace natural gas during peak evening hours. Batteries charged with excess midday solar power generated an average of 4.9 GW between 5:00 p.m. and 9:00 p.m. in 2025, up from less than 1 GW in 2022. These changes indicate that solar energy and storage are increasingly reducing California’s dependence on natural gas for electricity.