July 17, 2025
Global Renewable News

CALIFORNIA INDEPENDENT SYSTEM OPERATOR CORPORATION
California ISO records banner year for renewables integration
2019 saw historic amounts of solar, wind resources in the electric grid

February 5, 2020

The electric grid managed by the California Independent System Operator (ISO) delivered record-breaking amounts of solar and wind energy in 2019, according to the company's 2019 Statistics fact sheet posted today (2/3).

The ISO published the document to help the public easily access key data about its power grid and wholesale energy market, part of a continuing commitment to transparency and raising awareness about the high-voltage electric system during its transition from fossil fuels.

The data is an especially valuable technical resource as the ISO manages growing amounts of renewable energy onto its grid, on its way to supporting the state's carbon reduction goals. The statistics also illustrate the benefits of regional collaboration through its Western Energy Imbalance Market (EIM), and emerging technology and market policies geared to decarbonizing the system.

Some highlights of the fact sheet include:

  • A historical peak of 80.3% of renewables serving demand on May 15.
  • A peak demand for electricity of 44,301 megawatts (MW) on Aug. 15.
  • Historic solar generation peak of 11,473 MW on July 2.
  • Historic wind generation peak of 5,309 MW on May 8.

The data also showed the highest amount of wind and solar resources, 223,195 MWh, were curtailed in May 2019, an important historic peak to track as the ISO contends with potential capacity shortfalls and intensified evening ramps due to rising renewable resource integration.

To view ISO's energy peaks and historical data by month, view Monthly Stats on the News webpage. Follow the ISO's real-time supply and demand, along with other key energy data points, at the ISO's Today's Outlook. Download the ISO Today mobile app on your device, and follow us on Twitter at @California_ISO.

The California ISO provides open and non-discriminatory access to one of the largest power grids in the world. The vast network of high-voltage transmission power lines is supported by a competitive energy market and comprehensive grid planning. Partnering with about a hundred clients, the nonprofit public benefit corporation is dedicated to the continual development and reliable operation of a modern grid that operates for the benefit of consumers. Recognizing the importance of the global climate challenge, the ISO is at the forefront of integrating renewable power and advanced technologies that will help meet a sustainable energy future efficiently and cleanly.

Contact:
Anne Gonzales | agonzales@caiso.com
Vonette Fontaine | vfontaine@caiso.com

For more information

California Independent System Operator Corporation

www.caiso.com