heat wave

FAQ: What to Know About Flex Alerts and Power Emergencies in California

Rotating power outages, typically ordered in California during sweltering summer heat waves, when power demand reaches levels that strain the state's electrical grid, are possible over the next few days.

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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.
  • The operator of California's power grid declared a flex alert Thursday, warning of rotating outages due to high demand.
  • The last time a Stage 3 alert was issued in 2001 during the energy crisis.

A statewide Flex Alert, a 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 call for residents to voluntarily conserve power across California will be in effect during Thursday amid a fall heat wave.

The California Independent System Operator issued the statewide Flex Alert from 3 p.m. to 10 p.m.

Here’s what to know.

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.

What happened Aug. 14?

Cal ISO issued a Stage 3 power emergency alert at 6:36 p.m. The operator had earlier issued a Flex Alert, urging Californians to conserve power in anticipation of Friday’s high demand. By 7:51 p.m., the grid stabilized and utilities began restoring electricity that had been taken out of service. The emergency declaration was lifted at 8:54 p.m. Stage 3 alerts mean the ISO is unable to meet minimum reserve requirements and load interruptions are imminent. 

What led to the Stage 3 emergency?

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

Why shut off power on a rotating basis?

A Stage 3 Emergency is declared when demand outpaces available supply. The August order was declared after extreme heat drove up electricity demand, causing the ISO to dip into operating reserves.

"Although a Stage Emergency is a significant inconvenience to those affected by rotating power interruptions, it is preferable to manage an emergency with controlled measures rather than let it cause widespread and more prolonged disruption,'' Cal-ISO said.

What happens when 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.

Was everyone affected?

After CalISO issues the power outages alert, it's up to local utilities to manage load. In Southern California on Friday, SoCal Edison announced at 7:45 p.m. 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.

What about LADWP?

The Los Angeles Department of Water and Power said the rolling blackouts did not affect residents of the city.

"LADWP is a municipally owned utility and owns its own generation, but has the ability to buy and sell power back and forth to the rest of the grid as needed and as available," said LADWP public relations specialist Paola Adler. "Our own generation and transmission are the reasons we aren’t 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.

Will there be more rotating blackouts during the heat wave?

Possibly. Temperatures throughout California are expected to remain high, increasing demand for power as air conditioning use soars. The power grid operator will decide whether to continue the rolling outages on a day-to-day basis, according to Cal ISO.

What happens before we reach Stage 3?

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.

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.
Copyright AP - Associated Press
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