What to Know
- California was on the verge of widespread rotating blackouts Tuesday afternoon when demand for electricity reached an all-time high.
- Gov. Newsom credited 27 million alert messages sent to phones statewide calling with helping to stave off power outages.
- As of early Wednesday afternoon, forecasted peak demand was expected to hit 51,329 MW later Wednesday afternoon.
California has so far weathered a heat wave that pushed electricity demand to an all-time high without the need for widespread rotating power outages.
The nation's most populous state was on the verge of planned outages when CAISO, the agency that manages the power grid, issued an Energy Emergency Alert 3 Tuesday afternoon. The ISO alert means demand, much of it from air conditioners, might pass supply and rotating blackouts might be ordered to ease strain on the grid.
CAISO announced Wednesday night that it would be extending the statewide flex alert through Thursday. This will be the ninth straight day of a flex alert as the high temperatures continue to linger. The flex alert issued will be in effect from 3 p.m. to 10 p.m.
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CAISO said the peak electricity demand on Tuesday hit 52,061 megawatts, far above the previous high of 50,270 megawatts set on July 24, 2006. There were no rotating outages over large areas, but some outages were reported in the San Francisco Bay Area cities of Palo Alto and Alameda for about an hour.
Demand dropped later in the evening as businesses closed, and CAISO ended the Energy Emergency Alert 3 at about 8 p.m. CAISO tweeted that "consumer conservation played a big part in protecting electric grid reliability."
Alert messages were sent to millions of cell phones, urging Californians to cut power use. Gov. Gavin Newsom said the messages worked well, but expressed concern about over-using the message system.
Newsom, speaking to reporters in Beverly Hills, said 27 million messages were sent statewide calling for immediate power conservation.
"Within minutes, we saw a roughly 2,600-megawatt reduction in usage," Newsom said. "Had that not happened, we would have had some episodic load reduction. That was extraordinary.''
As of early Wednesday afternoon, forecasted peak demand was expected to hit 51,329 MW later Wednesday afternoon, according to the CAISO web site. Current capacity was at 58,675 MW.
Thursday's peak forecast was 51,318 MW.
Excessive heat warnings remain in effect throughout Southern California. Relief, but not much, is expected this weekend when temperatures take a slight dip.
California and other Western states are still struggling through one of the hottest and longest September heat waves on record. Temperatures began soaring last week and the National Weather Service warned that dangerous heat could continue through Friday, despite some slight moderation.
Sacramento hit an all-time high Tuesday of 116 degrees breaking a 97-year-old record.
Scientists say climate change has made the West warmer and drier over the last three decades and will continue to make weather more extreme and wildfires more frequent and destructive. In the last five years, California has experienced the largest and most destructive fires in state history.
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?
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 Elliot Mainzer, president and chief executive officer of the California Independent System Operator.
At a Monday news conference, officials said the voluntary calls for conservation appear to be working, so far. Grid managers said they are closely monitoring supply-demand balance as extreme heat continues this week for most of California.
On Tuesday, the state was on the verge of planned outages as demand reached all-time highs in the afternoon.
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."
When rotating power outages are declared, residents should check timing with their local utility company.
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.