What to Know
- California is facing its most likely chance of blackouts this year as a heat wave grips the state.
- A Flex Alert was extended for a seventh day in a request from power grid operators to voluntarily limit power use during peak times.
- If the voluntary effort and other measures aren't enough to balance demand and supply, the state's power grid operator may issue alerts in stages before calling for rotating power outages.
Cal-ISO has declared an Energy Emergency Alert 3 Tuesday afternoon with rotating power outages very possible. This alert comes as an unrelenting nearly week-long heat wave pushes the state's demand for electricity to unprecedented levels.
The demand for power Tuesday is expected to reach an all-time high, power officials said.
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"As the state faces the hottest day in this prolonged, record- breaking heat wave, grid conditions are expected to worsen,'' according to the power-grid manager. "If needed, ISO could order utilities to begin rotating power outages to maintain stability of the electric grid. If that occurs, consumers should expect communications -- either phone, text or email -- from their utilities notifying them of outage areas and likely durations."
The announcement marked the most urgent in a series of calls from Cal ISO and others to conserve power during the heat wave.
"This is an extraordinary heat event we are experiencing, and the efforts by consumers to lean in and reduce their energy use after 4 p.m. are absolutely essential,'' said Elliot Mainzer, the California ISO's president and CEO.
The California Independent System Operator extended a statewide Flex Alert -- a call for voluntary power conservation -- again for Tuesday afternoon and into the evening. Residents are asked to take all possible measures to conserve electricity during the peak hours of 4 p.m. to 9 p.m. for the seventh consecutive day.
"We are now heading into the worst part of it," Gov. Gavin Newsom said in a tweet Tuesday.
After Flex Alerts, grid managers have several options before rotating power outages, such as tapping backup generators, buying more power from other states and using so-called demand response programs, where people are paid to use less energy.
The agency also declared a Energy Emergency Alert 2 on Monday. The alerts are part of the demand-supply balancing act that Cal ISO performs to avoid power interruptions in the nation's most populous state.
If power demand-supply conditions continue to deteriorate, the ISO would instruct utilities in its service area to manage rotating power outages. Utilities make the determination of how best to spread and rotate the outages across their service territory, with the goal of keeping them as short as possible.
"We never want to get to that point, of course, but we want everyone to be prepared and understand what is at stake," Manzier said. "We can't control the weather, but we really can bend the demand curve and get through this successfully if everyone doubles down and reduces their energy use as much as possible."
If rotating power outages are declared, residents should check timing with their local utility company.
Current forecasts predict peak demand at 51,145 megawatts on Tuesday, which would break the record of 50,270 MW in 2006, according to the ISO. Wednesday's load is forecast at 50,002 MW. The ISO is projecting supply deficiencies of 400 to 3,400 MW between 5 p.m. and 9 p.m. Tuesday.
Consumer and commercial demand response, including Flex Alerts, has been helping to extend tight resources over the past week, with a load reduction of around 1000 MW for each of the past several days.
Here's what to know about rotating power outages and how they're managed.
What can I do to help prevent rotating power outages?
CalISO offers the following power conservation tips when a Flex Alert is issued.
- 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 power?
What happens if Flex Alerts aren't enough?
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 if the voluntary calls to conserve do not appear to be working.
- Energy Emergency Alert 1: Real-time analysis shows all resources are in use or committed for use, and energy deficiencies are expected. Market participants are encouraged to offer supplemental energy and ancillary service bids. Consumers are encouraged to conserve energy.
- Energy Emergency Alert 2: Cal ISO requests emergency energy from all resources and has activated its emergency demand response program. Consumers are urged to conserve energy to help preserve grid reliability.
- Energy Emergency Alert 3: ISO is unable to meet minimum Contingency Reserve requirements and controlled power curtailments are imminent or in progress according to each utility’s emergency plan. Maximum conservation by consumers requested.
How likely are rolling power outages in California?
Very likely, judging by Tuesday's power demand forecasts.
On Saturday night, the state used about 44,000 megawatts of electricity, according to Cal ISO. By Tuesday, that's supposed to ramp up to more than 50,000 megawatts, nearing record levels of energy use set in 2006. But the state would rather curb demand to avoid that number than test the power grid's capability to respond.
“Our goal is to make sure that we do not reach that number," said Mainzer.
In August 2020, Cal ISO issued a Flex Alert followed by its first Stage 3 Alert since 2001. Eventually, the grid stabilized and utilities began restoring electricity that had been taken out of service. 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?
Rotating outages can be a significant inconvenience, but they are a controlled measure used to manage emergencies. Without them, a widespread and more prolonged power disruption might result.
When was the last time California had rolling power outages?
Several hundred thousand Californians lost power in rolling blackouts in August 2020 amid hot weather. The state avoided a similar scenario last summer. Previously, the state ordered rolling outages 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 happens when rolling blackouts are ordered?
The California Independent System Operator 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.
After Cal ISO issues the power outages alert, it's up to local utilities to manage load. In Southern California during the summer of 2020, 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. The Los Angeles Department of Water and Power said the rolling blackouts did not affect residents of the city during the 2020 heat wave.
"The investor-owned utilities are responsible for determining the location and duration of the rotating outage within their service areas," according to Cal ISO. "Because the utilities are responsible for managing the rotating outages, consumers experiencing a power outage need to contact their electric power provider to learn when power will be restored."
How can I prepare for a power 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.