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Cal-ISO: Possible rolling blackouts for San Diego Wednesday amid scorching heat wave

Cal-ISO reported that the power grid peak demand hit 52,061 MW on Tuesday, a new all-time record.

SAN DIEGO — With electricity demand reaching record levels due to a drawn-out heat wave, Southern California and the whole state avoided rolling power blackouts as the manager of the power grid called for maximum conservation efforts by residents.

The California Independent System Operator extended a Flex Alert until Wednesday, urging residents to take all possible measures to conserve electricity during the peak hours of 4-9 p.m. for the eighth consecutive day.

Just after 8 p.m. Tuesday, California ISO tweeted that "the grid operator ended its Energy Emergency Alert (EEA) 3 with no load sheds for the night. Consumer conservation played a big part in protecting electric grid reliability. Thank you, California!"

Less than an hour prior, around 7 p.m., California ISO reported that the power grid peak demand hit 52,061 MW, a  new all-time record. The previous high was in July of 2006 with a demand of 50, 270 MW according to the tracking of peak load history from 1998-2022 on Cal ISO's website. 

Wednesday's load is forecast at 49,868 MW which could trigger similar alerts.

The operator of the state's power grid had warned of an increased likelihood of power shortages Tuesday unless consumers were to reduce their energy use even more than they have so far, as California continued to bake under an unusually long heat wave that has produced record high temperatures.

The California Independent System Operator extended a Flex Alert Tuesday, urging residents to take all possible measures to conserve electricity during the peak hours of 4-9 p.m.

On Tuesday, The California Independent System Operator issued an Energy Emergency Alert 2, in effect from 4 to 9 p.m. The alert means the state's power grid manager is requesting emergency supplies from all resources to meet what is expected to be a historic demand for electricity. Cal-ISO declared an Energy Emergency Alert 3 by about 5:30 p.m., which meant that rolling blackouts are imminent. 

SDG&E has a list of all potential circuits that could be affected if rolling outages go into effect in San Diego County. Circuit numbers are listed on your SDG&E bill in the section titled "Detail of Current Charges" under "Electric Service."  

The alert also heightens the call for residents to conserve power whenever possible to avoid rolling blackouts.

"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.

"Over the last several days we have seen a positive impact on lowering demand because of everyone's help, but now we need a reduction in energy use that is two or three times greater than what we've seen so far as this historic heat wave continues to intensify," he added.

If energy reserves are exhausted, the ISO would instruct utilities in its service area to manage rolling blackouts. 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," Mainzer said. "But we want everyone to be prepared and understand what is at stake. 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."

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.

During the Flex Alerts, residents are urged to take the following power-saving steps:

  • setting thermostats to 78 degrees or higher;
  • avoiding use of major appliances;
  • turning off unnecessary lights; and
  • avoid charging electric vehicles.

How to prepare for power outages

Utility officials also recommend you follow these suggestions to help you prepare for blackouts.

  • When it comes to food, make your own ice ahead of time, freeze containers of water to keep food cold while your power is off.
  • Before the outage begins, try to grab what you need from the refrigerator and limit opening its doors. Food can be kept cold for up to four hours in refrigerators and up to 48 hours in freezers. 
  • Make sure to turn off unplug electrical appliances or any equipment.
  • Keep flashlights in reach, but avoid candles as they can cause fires.
  • Most importantly stock up on food supplies for you and your pet.
  • Residents are also advised to pre-cool their homes as much as possible and close blinds and drapes to keep interiors cool.

After a power outage 

Officials also recommend that you throw away any food that has developed an unusual odor.

You should also restock your emergency kit with fresh batteries, canned foods and other supplies. 

Southern California has seen temperatures soar above 100 degrees every day since last Wednesday, with little relief in sight until at least Friday.

Overnight lows are not offering much relief either, staying in the 70s and even in the low 80s in some of the hotter areas.

The National Weather Service extended the excessive heat warning that has been in effect all weekend, which is now set to expire at 8 p.m. Friday.

"Strong high pressure to the north will continue the heat wave through Thursday for inland areas, with the heat continuing through Friday for the coast and valleys," according to the NWS. "For next weekend, a weakening tropical system will bring increasing moisture, breezy conditions, and a chance of more widespread showers and isolated thunderstorms. Showers and higher humidity will linger through early next week."

Health officials advise residents to stay indoors with air conditioning whenever possible, drink plenty of fluids and avoid hiking or other strenuous activity in extreme heat.

Children and pets should never be left in unattended vehicles for even one minute.

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