Texas power grid survives another close call; CPS Energy thanks San Antonians for conserving

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This story was updated on 8/24/23 at 10:30pm CDT:

The Texas power grid survived another close call Thursday evening. While record energy demand came dangerously close to the available supply, a need for rolling blackouts did not arise — as San Antonio officials had warned.

CPS Energy, the municipally owned utility, thanked San Antonio residents on social media for "doing their part to conserve today."

ERCOT, the state’s grid operator, issued a conservation appeal Thursday until 10 p.m. due to tight power conditions and continued near-record demand.

Average hourly demand hit over 84,200 megawatts at around 5 p.m. Thursday, approaching the last demand record set on August 10th at just over 85,400 megawatts.

An ERCOT weather watch remains in effect until Sunday.

San Antonio Mayor Ron Nirenberg asked residents to conserve power on Thursday. He said there was a possibility of power outages between 6:00 p.m. and 9:00 p.m. in 15 minute increments.

"Number one, remain calm, follow instructions from officials and local authorities, and help us again by conserving energy," he said. "Two, find an alternative power source plan for batteries and alternative power sources to meet your needs. When power goes out, such as a portable charger or power bank and have flashlights ready. Remember never use a generator indoors."

He added: "Number three, know your medical needs. If you rely on electricity for medical needs, make certain a power outage plan for your medical devices or refrigerated medicines is trained for."

Nirenberg asked residents to unplug all devices to avoid damage from electrical surges and keep refrigerators and freezers closed to preserve food.

BREAKING: San Antonio’s Office of Emergency Management just sent a wireless alerts to warn of potential power outages this evening. pic.twitter.com/Iw5DJhMqD8

He added that there were several locations throughout the city for people to cool off if needed.

"The City of San Antonio libraries are available for residents who need a cool place to stay," Nirenberg explained. "They will remain open until 9 p.m. tonight. At all parks, and that goes for parks and community centers for residents who need a cool place to stay. ... We will have a list of libraries, senior centers and county facilities that will remain open until 9 p.m., and VIA will provide no cost transportation to those facilities."

There was more information on city resources at saoemprepare.com.

CPS Energy CEO Rudy Garza said it would be up to ERCOT to call for rolling outages.

"When ERCOT makes that call, the entire state — based on its load share of the system — had to respond with that amount of load so that we balance the system out while we’re in that condition. Maybe we get there today, maybe we don’t,” Garza said.

Earlier on Thursday, Pablo Vargas, the CEO of the Electric Reliability Council of Texas (ERCOT), said electricity supplies in Texas will be tighter than ever on Thursday, just as triple digit temperatures returned to San Antonio. He called on customers to conserve energy.

BREAKING NEWS: San Antonio Mayor Ron Nirenberg says there is “very strong probability” for power outages tonight due to energy demand on the ERCOT power grid. If it happens, the rolling blackouts would be called by ERCOT and last about 15 minutes. pic.twitter.com/rXqkA1HFVf

ERCOT issued an appeal to conserve energy until 10:00 p.m.

It requested that all government agencies, including city and county offices, to implement all programs to reduce energy use at their facilities.

There have been calls for voluntary energy conservation this summer, including two in the past week, but this was more urgent.

Joshua Rhodes, an energy analyst at UT Austin, offered some tips on how people can reduce energy use and help protect grid stability.

"Maybe don't start that load of laundry until 10 o'clock or so. And if it's safe to do, maybe have it at just a degree or two warmer. One of the tricks people can do is actually pre-cool their home. So cool it down a little further earlier in the day and then let the thermostat go up a few degrees so that the temperature stays comfortable.”

ERCOT also called for conservation on the part of large electric customers that have volunteered to lower their energy use in this kind of situation.

The advisories triggered concerns that began with 2021's winter storm, when the power grid collapsed and left much of the city and state in freezing — and in some cases, fatal — darkness.

Jerry Clayton, Fernando Ortiz Jr., Marian Navarro, and KUT's Trey Shaar contributed to this report.