Extended drought conditions could cut summer electricity generation from hydropower in California nearly in half compared with normal precipitation conditions, according to the U.S. Energy Information Administration (EIA).

Projections indicate that hydropower would produce 8% of California’s electricity generation in a drought year, compared with 15% under normal precipitation conditions. The agency expects that level of decrease in hydropower generation would lead to an 8% increase in California’s electricity generation from natural gas, a 6% increase in energy-related carbon dioxide emissions in the state, and an average 5% increase in wholesale electricity prices throughout the western U.S. The forecast is based on analyses of six of California’s hydropower facilities, representing 22% of the state’s hydropower capacity,

California power generation mix forecast for the summer of 2022. Source: EIA

Hydropower is typically the third-largest source of electricity in California, but electricity generation from this source is highly reliant on snowpack that forms in the winter season. Snowpack in the state was above normal as of December 2021, but it was 40% below normal levels by the start of April 2022. The replacement power to make up for the reduced hydroelectric generation is about evenly divided between an increase in out-of-state market purchases and in-state natural gas generation.