California expects lower hydro, more gas in power mix

California expects to see the share of hydro power in its electricity mix fall to nearly half normal levels this summer, with an expected increase in natural gas power generation, the US Energy Information Administration (EIA) said June 1.

In a supplement to its May Short-Term Energy Outlook (STEO), the federal agency said an ongoing drought – now in its third year – would push hydroelectric generation in the state this summer down by 48%, compared to a normal water year.

“During the 2022 water year, which began October 1, 2021, snowpack reached above-normal levels in December, but dry conditions then persisted through March,” the EIA said. By April, when California’s snowpack normally peaks, the snowpack was about 40% below the median value between 1991 and 2020.

As a result of the reduced snowpack, the EIA expects hydro’s share in the California power generation mix will fall to just 8% this summer, compared to a 15% share in normal water years.

New solar capacity – about 8.8 GW has been added since 2015 – will pick up some of the slack, but the EIA expected California would need to import power from other jurisdictions and draw more heavily on in-state natural gas generating capacity, about 6.5 GW of which has been retired since 2015, pushing both prices and carbon emissions higher.

“As a result of more natural gas use in the drought case, we expect wholesale electricity prices in western US electricity markets would be 5% higher and energy-related carbon dioxide emissions in California would be 6% higher than the case with normal water supply conditions,” the EIA said.