As an unprecedented heatwave continued to strain California’s power grid, officials on Thursday issued a ninth straight Flex Alert — lasting two hours longer than previous daily statewide energy-limit announcements.
The last Flex Alert began at 3pm and will last until 10pm due to changing conditions which grid officials said could affect solar power supplies. Flex alert times for the past eight days have been from 4 p.m. to 9 p.m., during which the state narrowly avoided widespread power outages for several days.
“The main reason we extended [the alert is] primarily due to some uncertainty about how much production we will have from our renewable resources, primarily the sun, in the heart of the afternoon,” said Elliot Mainzer, president and chief executive officer of the California independent system operator that 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 sent smoke into the atmosphere.
As of Thursday evening, Cal ISO’s chart, which plots the supply of solar energy to the grid throughout the day – which usually resembles a smooth bell curve in clear conditions – showed a series of peaks and valleys as the amount of solar energy rose and fell with passing clouds jumped or smoke coverage, making it difficult for the network operator to forecast net demand.
As temperatures remained elevated across the state on Thursday, forecast peak energy demand was just under 50,000 megawatts, where demand peaked on Wednesday. On Tuesday, California set an all-time energy record with peak demand of 52,061 megawatts.
The ISO has also raised its energy emergency alert to Level 2 by 9pm Thursday, meaning “energy shortages are expected” and the grid operator is requesting emergency power from all resources.
Officials urged residents to charge devices and pull blinds to block sunlight.
During the seven hours of Flex Alert, ISO officials urged consumers to set thermostats to 78 degrees or higher, unplug unused appliances, turn off unnecessary lights and refrain from using larger appliances.
“This past week has been really, really, really challenging and I’ve just been so grateful and so impressed with the way California’s power consumers have come together,” Mainzer said. “They really recovered … and really helped us get through this extraordinarily challenging time.”
Mainzer said he hoped the state was “close to the tipping point” of the record-breaking heatwave and that the load on the power grid would ease soon.
The National Weather Service has predicted that most extreme heat warnings statewide will expire by Saturday.
https://www.latimes.com/california/story/2022-09-08/california-flex-alert-to-last-longer-on-9th-straight-day California Flex Alert to last even longer in ongoing heat wave