heat wave

Cal ISO Extends a Statewide Flex Alert Into Friday as Heat Grips California

A Flex Alert is a call for Californians to voluntarily reduce power use, typically during extreme heat.

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What to Know

  • A statewide Flex Alert is one of the steps the operator of the state's power grid can take to avoid unplanned power outages in extreme heat.
  • A Flex Alert is a call for resident to voluntarily conserve power, usually during peak times of day.
  • Cal ISO also may issue three levels of alerts to avoid emergency outages with Stage 3 being the most serious.

A statewide Flex Alert issued for Thursday afternoon was extended into Friday as late-spring temperatures soar across California.

The request to voluntarily reduce power use by California's power grid manager is the first of several steps that Cal ISO might take to avoid power interruptions in the nation's most populous state. The Flex Alert will be in effect Friday fro 6 p.m. to 9 p.m.

Parts of California have faced days of extreme heat that reached triple-digits in some areas.

Here’s what to know.

When the California ISO calls for a Flex Alert it means all Californians can jump in to help prevent power interruptions. Here's what you can do.

What can I do?

CalISO offers the following power conservation tips.

  • Turning off unnecessary lights.
  • Using major appliances before 3 p.m. and after 10 p.m.
  • Setting air conditioner thermostats to 78 degrees or higher.
  • Use fans and keep drapes drawn.

How will I know when there’s an urgent need to conserve?

Cal ISO has a notifications page where you can sign up to receive updates. Check you local utility's page for other alerts.

Didn't we do this last summer?

Cal ISO issued a Stage 3 power emergency alert in August 2020. The operator had earlier issued a Flex Alert, urging Californians to conserve power in anticipation of high demand. Eventually, the grid stabilized and utilities began restoring electricity that had been taken out of service. Stage 3 alerts mean the ISO is unable to meet minimum reserve requirements and load interruptions are imminent. 

What has to happen before a Flex Alert?

Temperatures around the state usually hit triple digits in many areas, and air conditioning use increases. In addition, cloudy weather from the remnants of tropical weather system last summer reduced power generation from solar plants.

What if things get worse?

Californians are familiar with Flex Alerts — a call for power conservation issued by Cal ISO in anticipation of high power demand. They usually happen during widespread extreme heat.

The system operator also may issue the following alerts.

  • Stage 1: Contingency power reserve shortfalls are happening or expected. There’s a strong need for power conservation. 
  • Stage 2: Cal ISO has taken all mitigating actions and is no longer able to provide its expected energy requirements. 
  • Stage 3: Cal ISO is unable to meet minimum contingency reserve requirements, and load interruption is imminent or in progress. Notice is issued to utilities of potential electricity interruptions.

When are rolling blackouts are ordered?

The California Independent System Operator, manager of the state’s power grid, declares a Stage 3 power emergency and directs utilities around the state to shed their power loads. If your local utility determines a need to shut off power, the blackouts typically last about an hour.

Do the Stage 1, 2, and 3 alerts affect everyone?

After CalISO issues the power outages alert, it's up to local utilities to manage load. In Southern California last summer, SoCal Edison announced that it had been instructed to begin rotating, one-hour service interruptions. Pasadena Water and Power also warned residents about the one-hour outages, while Anaheim officials said their outages would not last more than 15 minutes. But LADWP said its system was not affected.

When was the last time we had rolling outages?

The last time the state ordered rolling outages was during an energy crisis in 2001. Blackouts occurred several times from January to May, including one that affected more than 1.5 million customers in March. The cause was a combination of energy shortages and market manipulation by energy wholesalers, infamously including Enron Corp., that drove up prices by withholding supplies.

What can I do to prepare for an outage?

Below, you’ll find a few tips to get you through a power outage.

  • Update your contact information with your local energy company.
  • Have a back-up charging method for your phone and other devices.
  • Keep hard copies of emergency numbers and other important information.
  • Stock your emergency kit with flashlights, batteries, cash and first-aid supplies.
  • Do you know how to manually open your garage door? Try it out. 
  • Save operation of power-heavy appliances, such as dishwashers, washing machines and dryers, for early-morning and late-evening hours. 
  • Limit the opening and reopening of refrigerators.
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