LOS ANGELES — As an unprecedented heat wave continues to strain California's power grid, officials have issued a ninth straight "flex alert" — this one slated to last two hours longer than the previous daily statewide announcements to limit energy consumption.
Thursday's flex alert will begin at 3 p.m. and last till 10 p.m. Pacific time because of changing conditions that power grid officials say could stunt solar energy supplies. The flex alert hours for the last eight days have been from 4 to 9 p.m., during which the state has narrowly avoided widespread rolling blackouts on multiple days.
"The principle reason we've extended (the alert is) largely due to some uncertainty about how much production we will have from our renewable resources, primarily the solar, during the heart of the afternoon," said Elliot Mainzer, president and chief executive of the California Independent System Operator, which runs the state's power grid.
Smoke and cloud cover in Northern California are expected to affect solar power supplies, Mainzer said. A wildfire burning west of Lake Tahoe was sending smoke billowing into the atmosphere.
He said California is expecting even higher power demands Thursday evening compared with Wednesday, as temperatures across the state are forecast to be a bit higher. On Tuesday, California set an all-time energy record, with peak demand at 52,061 megawatts.
Cal ISO also issued the first step of its Energy Emergency Alert for Thursday afternoon, which means "energy deficiencies are expected."
Officials are urging residents to pre-cool homes before 3 p.m., charge devices and draw window shades to block sunlight.
During the seven hours of the Flex Alert, Cal ISO officials are asking consumers to set thermostats to 78 degrees or higher, unplug unused devices, turn off unnecessary lights and not use major appliances.
"This last week has been really very, very, very challenging, and I've just been so appreciative and so impressed with the way California electricity consumers have come together," Mainzer said. "They've really rallied ... and really helped us work through what has been an extraordinarily challenging time."
Mainzer said that he's hopeful the state is "close to turning the corner" on the record-setting heat wave, and that the stress on the power grid will soon be alleviated.
The National Weather Service has predicted most of the extreme heat warnings across the state will expire by Saturday.