In the most detailed explanation yet, Electric Reliability Council of Texas CEO Bill Magness provided a timeline of what went wrong during last week’s winter storm, when millions of Texans were left without power for days as freezing temperatures persisted.
Magness gave the presentation Wednesday during the first ERCOT board of directors meeting since the winter storm passed through the Lone Star State. Shortly before the meeting, up to six board members submitted their resignations due to the widespread outages.
“I want to emphasize what ERCOT wants to do today, what ERCOT wants to do at the legislative hearings tomorrow and going forward is provide an explanation, not excuses,” Magness said.
Leading up the winter storm, ERCOT took a number of steps to prepare for the potential of outages, including asking the Department of Energy for a waiver to allow for increased emissions due to increased output.
But very quickly into the storm, between Feb. 14 and Feb. 15, outages began piling up.
As the generation started to plummet, ERCOT had to order local utility companies to shed load — meaning instituting outages to keep the grid stable.
In all, Magness said the state grid lost 48.6% of power generation at the peak of outages. Because the load-shed demand was so high — reaching a peak of 20,000 megawatts — local utilities were severely limited in their ability to rotate the outages as they had planned, Magness said.
The most critical moments came before 2 a.m., where the graph above is shaded in red.
If the supply and demand for power remained that out-of-balance long enough, it could have led to uncontrolled blackouts that would have left Texans out of power indefinitely, Magness said.
“We may still be here talking about when is the power going to come back on if we let the system get into that condition,” Magness said.
Magness’ presentations also included comparisons to Texas’ last severe winter storm in 2011.
The Dallas-Fort Worth area had been at or below freezing temperatures for 140 consecutive hours, compared to 101 hours in 2011′s winter storm. In Austin, the city was at freezing temperatures for 162 consecutive hours, compared to 69 hours in 2011.
The duration of those freezing temperatures affected the state grid’s ability to recover its generation, elongating the extent of the controlled outages.
One of the board members, Austin Energy General Manager Jacqueline Sargent, lamented over ERCOT officials’ behavior during a Feb. 9 meeting before the storm, where they spent less than 40 seconds talking about the winter storm.
“The concerns with regard to the upcoming weather event should have been communicated more specifically, and I feel as a board member very frustrated that did not occur,” Sargent said.
“I’m sorry that we did not cover that in more depth,” Magness responded.
ERCOT officials will testify about the winter storm outages in front of the Texas Legislature on Thursday.
You can read more about Magness’ presentation below: