What is a Flex Alert?

thermostat-adjustmentA Flex Alert is a call for consumers to conserve electricity during heat waves when power use outstrips electricity supply and other challenging grid conditions, such as when power plants or power lines are unexpectedly unavailable making electricity deliveries difficult.

Who issues a Flex Alert?

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A Flex Alert is issued by the California Independent System Operator (ISO), a  nonprofit, public benefit corporation that operates the high voltage grid in California and in parts of eight western states.  The ISO does not own transmission lines or power plants, but does tell power plants when to generate electricity, how much to generate and where the electricity will be delivered. The ISO is regulated by the Federal Energy Regulatory Commission in Washington, D.C. Read more about the ISO here.

How is a Flex Alert communicated?

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Receive Flex Alerts on your phone by downloading our mobile app ISO Today. You can also see what the grid conditions are on a minute by minute basis.

Sign up to receive Flex Alerts by entering your information in the green box above. If you are part of a business or organization, consider forwarding emergency notifications to your staff, members or email list(s).

Flex Alerts are posted on the ISO website, sent in direct emails and texts to consumers who sign up for notifications, and posted to Twitter and other social media. The ISO notifies  media when it issues a Flex Alert as well.

WHAT can trigger Flex Alerts?

Reasons may include the following:

  • high peak demand
  • unplanned power plant outages
  • fires that cause transmission line overloads, losses, or limitations
  • humid, hot weather and heat storms.

When is a Flex Alert issued?

A Flex Alert is most effective when issued a day in advance of when conservation is needed so consumers can adjust their electricity usage ahead of time such as turning thermostats off before leaving for work.

However, grid emergencies can happen suddenly, so if conservation is needed, the ISO will issue a Flex Alert with little or no advance notification. When possible, Flex Alerts are targeted to the local areas where the system is stressed.