The extended drought in California could cut the state’s summer electricity generation from hydropower nearly in half compared with normal precipitation conditions, according to an analysis by the US Energy Information Administration (EIA). EIA’s analysis indicates that hydropower would produce 8% of California’s electricity generation in a drought year, compared with 15% under normal precipitation conditions.

EIA 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 (CO₂) emissions in the state, and an average 5% increase in wholesale electricity prices throughout the West given the current system configuration.

Figure 1 data source: US Drought Monitor, jointly produced by the National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. Graph courtesy of NDMC.
Figure 2 data source: US Energy Information Administration, Electric Power Monthly

California has a diverse electricity fuel mix and is highly interconnected with the regional electric grid, but our study shows that a significant decrease in hydropower generation this summer could lead to higher electricity prices, among other effects.

—EIA Administrator Joe DeCarolis

Hydropower is typically the third-largest source of electricity in California, but electricity generation from hydropower is highly reliant on snowpack that forms in the winter season. California’s snowpack was above normal as of December 2021, but it was 40% below normal levels by 1 April of this year.

EIA analyzed six of California’s hydropower facilities, representing 22% of the state’s hydropower capacity, to develop its supplemental outlook.