California Faces Blackout Risks Through Labor Day Holiday

The state’s grid operator is urging residents to cut back on energy use during the hottest parts of the day, when thermostats in some parts of the Central Valley are forecast to hit highs of 115 degrees Fahrenheit (46 degrees Celsius) into the middle of next week. The searing heat will push electricity demand to the highest levels in years. Demand on Thursday hit a peak of 47,357 megawatts, the highest since September 2017, grid officials said.

“We want everyone to know that the hottest weather in this extended heat wave is still ahead of us,” Elliot Mainzer, chief executive officer of the California Independent System Operator, said Friday in a video. “Electricity conservation is going to be essential to keeping the power flowing to California without interruption.”

Shortly after posting Mainzer’s video statement, Caiso issued an grid emergency watch for 6 p.m. to 8 p.m. on Saturday, when energy shortages are expected.  The grid operator is also calling for homes and businesses to reduce power Saturday afternoon and early evening.

The threat of outages underscores the power grid’s increasing vulnerability as climate change disrupts weather patterns amid the push to transition from fossil fuels to renewable energy. California is enduring its worst drought in 1,200 years, sapping hydropower production.

At the same time, older gas-burning plants have been closing faster than solar, wind and battery facilities can replace them. Earlier this week, California lawmakers nearly unanimously approved a bill to extend the life of the state’s only remaining nuclear power plant by five years as a protection against blackouts.

The extreme heat already has taken down a number of power generators this week, Caiso said in a statement Friday. Grid operators said they are also concerned about two major wildfires threatening transmission lines and power plants near Los Angeles and San Diego.

“The challenge continues until this heat wave dissipates,” Mainzer said.