Utility-Scale Solar Generation Surpasses Natural Gas In California

2 minute(s) Read

June 17, 2026

Staff

By Kimberly Peterson, Katherine Antonio, and Lori Aniti

In the first five months of 2026, utility-scale solar generation surpassed natural gas generation in the California Independent System Operator (CAISO), according to data from the Energy Information Administration (EIA). Solar electricity generation in the CAISO over the first five months of 2026 increased 21% compared with the same period in 2024, and natural gas generation decreased by 60%, according to EIA Hourly Electric Grid Monitor data.

Graphic courtesy of the US Energy Information Administration (EIA) with data by the EIA’s Preliminary Monthly Electric Generator Inventory.

In CAISO, utility-scale solar generated more electricity than natural gas on a daily basis on 82% of days in the first five months of 2026, up from 21% in 2024 and 2025.

Both solar generating capacity and battery storage capacity have grown in CAISO over the past two years, while natural gas generation capacity has remained flat, according to our Preliminary Monthly Electric Generator Inventory. From April 2024 to April 2026, utility-scale solar capacity increased 19% to 25 GW, and net battery storage capacity increased 79% to 16 GW. Natural gas capacity remained nearly unchanged at 29 GW. Total net capacity increased by 14%, 11 GW, over this period.

Graphic courtesy of the US Energy Information Administration (EIA) with data by the EIA, Today’s Outlook five-minute power supply data.

Battery storage, often co-located with solar, charges when solar generation exceeds grid needs during the day and supplies power to the grid in the evening and early morning when there is less sun. In the first five months of 2026, battery storage discharge tripled compared with the same period in 2024.

Despite increasing generation from solar and batteries and a 7% increase in demand over this period, net generation decreased by 19% as electricity imports from nearby systems doubled in CAISO. The increase in imports was driven by relatively inexpensive electricity generation coming online and available for import.

Hydroelectric power imports from the Pacific Northwest increased as the drought there subsided, and CAISO began importing from the new SunZia wind project in New Mexico starting in April of this year. In addition, generator retirements in CAISO between May 2024 and May 2025 totaled 550 MW and included a 300 MW battery installation that caught fire in January of 2025.

About The Authors

Kimberly Peterson is an economist and Today in Energy editor at the US Energy Information Administration.

Katherine Antonio is currently contributing to the US Energy Information Administration as an economist.

Lori Aniti is an economist at the US Department of Energy.