2021 Total System Electric Generation

Total System Electric Generation and Methodology

Total system electric generation is the sum of all utility-scale, in-state generation, plus net electricity imports. Items of note for 2021:

• Total generation for California was 277,764 gigawatt-hours (GWh), up 2 percent, or 5,188 GWh, from 2020.
• Renewable energy generation increased 3.5 percent in 2021, up 3,125 GWh to 93,333 GWh from 90,208 GWh in 2020.  However, as total system electric generation also increased in 2021, renewable energy accounted for 33.6 percent of the total system mix – a 0.51 percent increase from 2020.
• California’s non-CO2 emitting electric generation categories (nuclear, large hydroelectric, and renewables) accounted for 49 percent of its in-state generation, compared to 51 percent in 2020. The change is attributable to the continued impacts from California’s ongoing drought.
• In-state hydroelectric generation was significantly reduced, some 32 percent lower than 2020 generation levels, about 6,848 GWh lower.
• Net imports increased by about 2.4 percent (1,973 GWh) in 2021 to 83,636 GWh, partially offsetting the decreased output from California’s hydroelectric power plants.

In 2021, California once again experienced above average temperatures, as did nearly all of the Western U.S. Long-term weather stations reported record warmth in Nevada, Oregon, California, and New Mexico. All western states had stations reporting in the top ten warmest years on record. California experienced the fourth hottest year since year since 1895, as drought conditions continued in the state. As a result, annual in-state hydroelectric generation fell by 32 percent from 2020 levels to 14,566 GWh. Total hydroelectric generation, including imports, fell by 23 percent to 28,490 GWh from 37,023 GWh in 2020.

Imports

Electricity imports account for approximately 30 percent of total system electric generation each year. As part of the Western Electricity Coordinating Council (WECC), California is served by balancing authorities in other western states and Canadian provinces. Imports are grouped based on state or province of origin. The Northwest is made up of Alberta, British Columbia, Idaho, Montana, Oregon, South Dakota, Washington, and Wyoming. The Southwest category includes Arizona, Baja California, Colorado, Mexico, Nevada, New Mexico, Texas, and Utah.

Electricity imports, as shown in Chart 1, increased by 2.5 percent due primarily to increased imports from the Southwest. While the Pacific Northwest had above-average snowpack in early 2021, warmer temperatures in April resulted in record-breaking snowmelt, reducing hydroelectric availability in the summer when California would normally import energy to meet air conditioning loads. This fast snowmelt was also exacerbated by a record-breaking heatwave in June, resulting in 2021 being tied with 1936 as the warmest summer on record in the Pacific Northwest. Ultimately, a shift of energy imports to the Southwest helped maintain overall imports into California at similar levels as those observed in 2020.