California ISO Issues a Flex Alert for Friday, July 9 due to extreme heat, high demand

July 8, 2021


California-ISO

Consumers asked to conserve energy tomorrow from 4 to 9 p.m.

FOLSOM, Calif. – The California Independent System Operator (ISO) issued a statewide Flex Alert for Friday, July 9, citing extreme temperatures across much of California and a potential capacity shortfall on the state’s electric grid.

As a result of higher load, and supply forecasted to be tighter than expected on Friday, consumers are asked to voluntarily conserve electricity from 4 p.m. to 9 p.m. Such conservation would help ease the strain on the grid during the crucial evening hours when solar energy is diminished or no longer available.

When Flex Alerts were called in mid-June and during last summer’s regional heat wave in August and September, consumers answered the call and collectively made a significant reduction in their energy use. That allowed grid operators to avoid or limit possible rotating power outages that can become necessary when demand for electricity outstrips capacity.

While the Flex Alert is in effect on Friday from 4 p.m. to 9 p.m., consumers are asked to:

  • Set thermostats to 78 degrees or higher, if health permits
  • Avoid using major appliances
  • Turn off all unnecessary lights

To be as comfortable as possible during the Flex Alert hours, consumers are also strongly encouraged to take these steps earlier in the day:

  • Pre-cool your home by lowering the thermostat
  • Close window coverings to keep your home or apartment cool
  • If you need to use major appliances like your dishwasher, clothes washer and dryer, do so before the Flex Alert takes effect
  • Pre-charge electronic devices Close window coverings to keep your home or apartment cool
  • Pre-charge electric vehicles

For information on Flex Alerts, to get more electricity conservation tips, and to sign up for conservation alerts, visit the ISO's Flex Alert website. Visit the ISO's News page for more information on the heat wave's impacts on grid operations, and to learn more about alerts, warnings and emergency notices.

For updates on grid operations, follow us on Twitter at @California_ISO or @FlexAlert, or monitor system conditions in real time at ISO's Today's Outlook.

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A Flex Alert is issued by the ISO when the electricity grid is under stress because of generation or transmission outages, or from persistent hot temperatures. Glossary of terms and acronyms

Click here to learn more about System Alerts, Warnings and Emergencies. Follow grid conditions in real time at ISO’s Today’s Outlook, or download the free ISO Today mobile app.

This advisory is based on the best data available at the time of its release. Grid conditions can change rapidly and are subject to change without warning. This forecast is accepted by the recipient on the condition that errors, omissions and/or changes to the contents shall not be made the basis for any claim, demand or cause of action against the California ISO.