Days after North Texans began losing electricity, public officials say it is still difficult to determine how Oncor managed this week’s power outages. Oncor says it avoided cutting power to critical infrastructure like hospitals, prioritizing its outages on equipment that powered homes and businesses across its service area. It had to move so quickly that its messaging was broadened to tell the entire city it was at risk, leaving neighborhoods guessing at whether their power would shut off and for how long.
Mayor Eric Johnson said he was unaware of which parts of the city were losing power and when. Johnson, who is serving as the city’s emergency management coordinator during the standing disaster declaration, said he was told by Oncor CEO Allen Nye on Saturday that outages would roll through the city and not extend beyond 45 minutes.
“That obviously did not occur,” he said.
During a press conference Thursday morning, Johnson described challenging communication with the region’s largest electricity provider at a time when hundreds of thousands of North Texans were losing power during a historic winter storm. The mayor said it was unclear if the outages “were in fact decisions at all,” saying he had no such insight as to how power was distributed to residences and businesses throughout Dallas.
Oncor says many of those decisions were out of their hands. The Electric Reliability Council of Texas manages the state’s electric grid; providers like Oncor deliver the electricity. ERCOT ordered transmission companies to curb power to conserve enough to meet demand, so they did. Connie Piloto, a spokeswoman for Oncor, says the provider initially really did only expect rolling outages. And then ERCOT asked for more and more.
“What typically happens is ERCOT tells us to shed load, then it typically happens in 15- to 45-minute increments, but not this time, right?” Piloto says. “We had to shed so much that we couldn’t rotate. You could not get back up enough.”
Piloto tells D Magazine that the mayor and City Council knew what Oncor knew, which wasn’t different from the messaging it was delivering to the public and the media. But frustrated elected officials characterized this as poor communication since they didn’t know how Oncor was managing the outages, making it difficult to answer questions from constituents. Oncor says that, given the severity of the situation, it had to move quickly, and it wasn’t able to detail with any nuance the duration or geography of the outages.
Oncor says the “widespread power emergency” required it to “drop all available, non-critical load,” which means massive outages targeting lines serving residential and commercial customers, while saving critical infrastructure like hospitals. City officials say they were not provided details about where these were occurring, leading to questions and concerns about how equitably the outages were distributed. Oncor says equity had nothing to do with its decisions.
“These are diverse geographical areas across the grid, based solely on the mathematic and engineering needs of the electric system,” the company said in a statement.
Piloto says this was unprecedented for the energy provider. In 2011, when ice layered on roads following days of temperatures in the teens, ERCOT ordered Oncor to drop 4,000 megawatts over about seven and a half hours. This event lasted from Monday morning around 1:30 a.m. through Thursday. At the peak of the storm, ERCOT ordered Oncor to shed 20,000 megawatts across its service area, which includes most of North Texas and parts of Central and East Texas. According to ERCOT, 1,000 megawatts is enough to power 200,000 homes. At the peak of the outages, 1.3 million Oncor customers had no power.
“ERCOT is saying, ‘Oncor, you need to drop this amount of load,’ and we’re looking to determine how much of that load we can drop safely in order to protect the grid,” Piloto says. “There’s a playbook. You do this; you have to do it quickly; it’s happening in real time.”
“Safely” in that context means keeping the power flowing to critical infrastructure like hospitals, airports, and gas compression stations that feed power plants. If your home or business is connected to a line that also powers a hospital, you got lucky. That “playbook” she references is an automated plan for rotating outages. But at a certain point, rotating those outages won’t shed enough energy to save the grid. Oncor then targets service areas where it can shed the most power, which Piloto says is why there was a disparity in duration.
“Oncor is probably going to look at this and see if there was any way they could give more notice, but they may not be able to,” says Bruce Bullock, the director of SMU’s Maguire Energy Institute. “They were trying to rotate it equitably and found out that was very difficult to do. I suspect that’s going to be looked at as one of the things they may be able to do if that happens again.”
Piloto says the area north of Interstate 30 has 75 percent more feeders than its service area south of the highway. Feeders are the transmitters that provide energy to Oncor’s customers, meaning points north had more power to shed than those further south. But a majority of critical infrastructure is also above Interstate 30, leaving residents in older homes in southern Dallas vulnerable to outages.
On Monday, as more than 200,000 customers in Dallas County lost power, Mayor Johnson said he was assured by Oncor COO Jim Greer that “there was no inequitable intent” as to how the outages were occurring. The mayor said in his press conference that he will push for an investigation after the city digs itself out from an unprecedented array of burst water pipes, ice, and snow.
“I was assured,” he said of his conversation with Greer, “there was no plan that involved taking people off of the power grid in any way that would create an inequitable outcome, but I think we’re going to have to wait and see what was happening and what did occur and whether there was any intentional or unintentional inequity in whose power was turned off.”
Oncor maintains an outage map that allows residents to filter by ZIP code. It is updated every 20 minutes, intended to be a reflection of current conditions. But there is no way to see this information historically, making it difficult to draw conclusions outside of anecdotes.
Social media lit up about communities like Preston Hollow and the Park Cities having power while others languished, but Oncor’s ZIP code data didn’t at any point suggest that those parts of town were hit less hard. Considering how many people in the city couldn’t turn on their lights, we’ll need to see more detailed outage data to draw conclusions.
Most Dallas ZIP codes saw patterns that were difficult to parse. In southern Dallas, Councilman Casey Thomas said he never lost power but knew others nearby who didn’t have it for days. Near White Rock Lake, Councilwoman Paula Blackmon reported the opposite situation; she lost power, but her neighbors didn’t. Mayor Johnson said his home was out of power at various points from Monday through Wednesday.
Oncor’s online data aren’t specific enough to draw conclusions. When asked for a spreadsheet that would show outages by ZIP code and duration throughout the entire winter event, Oncor spokeswoman Kerri Dunn said this wasn’t immediately available because the agency’s top concern remains restoring power. On Thursday afternoon, about 33,000 Oncor customers in Dallas County still had no power.
By Friday, that number was down to about 13,000, the majority of which had no power because of mechanical problems that must be repaired. Transformers can blow after being powered back on after spending time off.
On Thursday, ZIP codes with more than 1,000 affected customers included 75061 in Irving and Las Colinas; 75254 in Far North Dallas; 75217 in southeast Dallas; 75104 in Cedar Hill; and 75052 southwest of Mountain Creek. On Friday, 75104, 75052, and 75039 in Irving were the only ZIPs with more than 1,000 outages.
It remains difficult to parse the distribution of the outages along lines that didn’t carry hospitals or other similar infrastructure. Rocky Vaz, the city’s director of the Office of Emergency Management, confirmed reports from Dallas council members that warming stations could not be arranged at recreation centers and libraries because Oncor could not guarantee they would have power. Instead, 19 coach buses are parked outside of public buildings throughout the city to serve as warming shelters. Vaz said some residents spent the night in those buses.
“Now we are moving into restoration of power and no blackouts,” Vaz said at the mayor’s Thursday press conference. “We are working through the process today to see if we can open up some of our rec centers and libraries and move people inside versus being on the buses. We’ll have our mobile warming stations until we can stand up our rec centers and libraries.”
The Kay Bailey Hutchison warming center remains open. It is also currently housing 750 unsheltered Dallasites.
As for the postmortem, Mayor Johnson is promising a robust investigation. But first, he said, we must get through the current crisis.
“Oncor is going to have to explain to us at the city and to everyone else, and ERCOT is going to have to explain to us and everyone else, exactly what was going on,” Johnson said. “Folks will have to wait until we can get through this situation before we get the ultimate clarity.”