California Blackouts Update as Residents Told to Conserve Electricity During Extreme Heat

California residents were advised to conserve energy to prevent further strain on the state's power system amid the ongoing heat wave across California and other parts of the country. No rolling blackouts are expected at this time, the California Independent System Operator (ISO), which manages the state's power grid, said late Thursday.

The ISO extended its Flex Alert through Friday, "asking consumers to again conserve electricity during the evening as California and states across the country work to relieve stress on electric grids due to extreme heat," according to a statement on Thursday.

A Flex Alert advises customers to save electricity by adjusting thermostats, turning off all unnecessary lights and avoiding the use of major appliances. Residents are also encouraged to use fans for cooling and to unplug any unused electrical items.

The Flex Alert, which was also in place Thursday from 5 p.m. to 10 p.m. local time, is scheduled for Friday 6 p.m. to 9 p.m. local time.

In a tweet late Thursday, the energy manager said the state's power grid is "stable" and "no rotating power outages are anticipated."

A Flex Alert is issued "when the electricity grid is under stress because of generation or transmission outages, or from persistent hot temperatures," the ISO says.

It is typically issued in the summer "when extremely hot weather pushes up energy demand as it reaches available capacity. This usually happens in the evening hours when solar generation is going offline and consumers are returning home and switching on air conditioners, lights, and appliances," the ISO explains.

Before the Flex Alert hours begin, residents can take the following steps during the day, as outlined by the ISO:

  • Pre-cool your home by lowering the thermostat
  • Use major appliances, like your dishwasher, and clothes washer and dryer
  • Close window coverings to keep your home or apartment cool
  • Charge electronic devices
  • Charge electric vehicles

The power grid manager said: "The ISO is continuing to monitor weather and grid conditions and will have additional announcements as information becomes available.

"Precise hours for a Flex Alert depend on hourly demand and supply forecasts and can change as conditions warrant," the ISO added.

The latest Flex Alert was issued following record-breaking temperatures this week. The highest temperatures ranged from 92°F to 115°F in parts of the western and central U.S., according to the National Weather Service.

The NWS tweeted Thursday: "Many other records have been set and more are likely today through the beginning of the weekend across the Central Plains and Southwest."

The NWS noted Wednesday that a total of 46.5 million people were reported to be "under a heat advisory (orange) or excessive heat warning (hot pink/magenta)."

"For those in these areas, stay hydrated and in an air conditioned place for as long as possible this afternoon and evening," the NWS tweeted Wednesday.

Power lines seen near Irvine, California.
Workers repairing power lines damaged in Orange County in December 2020 near Irvine, California. Residents across the state have been asked to conserve energy through Friday to prevent further strain on California's power grid amid the ongoing heat wave across the country. Mario Tama/Getty Images