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Flex Alert issued for Wednesday, July 28th, due to heat and tight supply

Posted on July 28, 2021


Flex Alert 07-28

Consumers urged to reduce energy use from 4-9 p.m. to protect grid reliability

FOLSOM, Calif. – The California Independent System Operator (ISO) has issued a statewide Flex Alert, a call for voluntary electricity conservation, for today, Wednesday, July 28 from 4 p.m. to 9 p.m., due to predicted high energy demand and tight supplies across the West.

With higher than normal temperatures in the forecast for parts of interior Northern California, the power grid operator is predicting an increase in electricity demand, primarily from air conditioning use. The increase can make electricity supplies tight and cause strain on our power grid.

Consumers are urged to conserve electricity, especially during the late afternoon and early evening, when the grid is most stressed due to higher demand and solar energy production falling. Consumers are also asked to turn off unnecessary lights, delay using major appliances until after 9 p.m., and set air conditioner thermostats to 78 degrees or higher, if health permits.

The conservation measures can help stabilize the power grid during a time of tight demand and supply, and avoid power interruptions. Reduced electricity use during a Flex Alert can prevent further emergency measures, including rotating power outages.

Tips before a Flex Alert:

  • Pre-cool home by setting the thermostat to as low as 72 degrees
  • Use major appliances:
  • washer and dryer – do laundry
  • oven and stove – pre-cook and prep meals
  • run the dishwasher
  • Adjust blinds and drapes to cover windows

Tips during a Flex Alert from 4 p.m. to 9 p.m.:

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

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.

Follow developing grid conditions at the ISO’s News webpage, under the System Conditions Bulletin, or follow us on Twitter at @California_ISO.

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.

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