With 58% of California now in exceptional drought conditions, the state's source of hydroelectric power is down sharply, while reliance on natural gas-fired generation and renewables increased steadily during a dry period stretching back to 2011.
On average, hydroelectric sources accounted for 20% of California's in-state power supplies during the first six months of each year between 2004 and 2013, according to a report released Monday by the U.S. Energy Information Administration (EIA). But hydropower accounted for only 10% of in-state electricity during the first half of 2014, the third consecutive drought year the state has experienced.
"Monthly hydropower generation in 2014 has fallen well below the 10-year range for each individual month [in 2014]," EIA said. "The dry conditions limit hydropower generation, requiring generation from other sources to make up for the shortfall."
When hydro supplies drop, gas-fired generation usually jumps above its 10-year average, and that is what EIA reported for the first half of this year. Natural gas-fired generation for the first six months of 2014 was 16% higher than the 10-year average, and 3% higher than in the first half of 2013.
Generally, natural gas-fired generation accounts for more than 40% of the state power supplies, according to the California Energy Commission (CEC), which tracks gas-fired generation statistics, along with other sources of power generation for its Integrated Energy Policy Report.
EIA said wind and solar generation also are playing bigger roles in California's in-state electricity mix, and for the first time, wind generation surpassed hydro as an electricity source for the state. Wind topped hydro in both February and March this year, the federal agency report said.
Another offshoot of the drought is a proposal now undergoing environmental and state coastal commission review involving construction of a desalination plant at Virginia-based AES Corp.'s Huntington Beach, CA, multi-unit gas-fired generation complex, where several units are idle. A water-producing plant would have to be coordinated with efforts to repower many of the gas-fired plants located along the coast to comply with a phased-in statewide ban on the use of seawater to cool power plants.