California grid operator issues flex alert ahead of high heat expected Wednesday

The sun sets amid clouds over the ocean.
With temperatures expected to climb in inland areas, California’s electrical system operator has issued a statewide flex alert.
(Gary Robbins / The San Diego Union-Tribune )

California’s electrical system operator is issuing a statewide flex alert for Wednesday, citing high temperatures expected across the region and spikes in power demand.

The flex alert will run from 4 to 9 p.m. Wednesday, officials with the California Independent System Operator said.

“With above-normal temperatures in the forecast for much of California and the West, the power grid operator is predicting an increase in electricity demand, primarily from air conditioning use,” said the nonprofit group, which manages the flow of electricity on high-voltage power lines and operates the state’s wholesale energy market.


Although temperatures along and near the coast were not of concern to officials, the National Weather Service’s Los Angeles office said inland and mountain portions of Southern California would see potentially dangerous levels of heat.

An excessive heat warning is in effect for the Antelope Valley through Wednesday, the Weather Service said. A heat advisory is in place until Friday for several areas, including the mountainous portions of Los Angeles, Ventura, Santa Barbara and San Luis Obispo counties.

Residents can expect temperatures to be five to 15 degrees above normal all week, the Weather Service said.

While the alert’s active, California residents are asked to set their thermostats to 78 degrees or higher, if health permits, and to avoid using major appliances and turning on unnecessary lights.


“Conserving electricity during the late afternoon and early evening is crucial because that is when the grid is most stressed due to higher demand and declining solar energy production,” the grid operator said.

The cooperation of residents during previous flex alerts has helped keep the power grid stable during periods of high demand, and prevented other emergency measures, including rolling blackouts, the grid operator said.

Here are some ideas for reducing power usage and cooling down while California’s flex alert is in effect.

Aug. 17, 2020

What to do during a flex alert:

  • Adjust your thermostat to 78 degrees or higher during the alert hours, unless medically necessary. Turn it off if you will not be home.
  • Use a fan instead of air conditioning when possible.
  • Draw drapes and turn off unnecessary lighting.
  • Keep the main refrigerator full (with bottles of water if nothing else) and unplug additional refrigerators.
  • Avoid using electrical appliances and devices. Put off tasks such as vacuuming, laundry, running the dishwasher and computer time until after 9 p.m. or do so earlier in the day.
  • Set your pool pump to run overnight instead of during the day.
  • Saving water saves energy.
  • Pre-cool your home by lowering the thermostat.
  • Find more tips at

Staff writer Hayley Smith contributed to this report.