Electric Reliability Council Of Texas Inc. representatives said Feb. 17 that the grid operator is still shedding about 13,000 MW of load as workers race to restore power to more than 3 million customers amid below-freezing temperatures.
Based on the current weather forecast and information from power generators, a full restoration of power is unlikely before the next day's morning peak in demand, Dan Woodfin, ERCOT's senior director of system operations, said on a press call.
As of 12 p.m. ET, ERCOT was reporting that a total of 46,000 MW of total generating capacity, or nearly 45% of available capacity originally forecast for this winter, had been forced offline by what has been described as a "once-in-a-generation" prolonged and a widespread burst of frigid Arctic air.
ERCOT said approximately 28,000 MW of the offline generation is thermal capacity and another 18,000 is renewable capacity. A total of 185 generating units have gone offline since ERCOT first began shedding load in the early morning hours of Feb. 15. Some of those units have tripped offline multiple times as operators struggle with frozen thermal generating units and wind turbines alike.
ERCOT CEO Bill Magness said on the press call that service will be fully restored as soon as enough generators can come back online. "Getting those resources back on the grid is the central solution to getting people their power back," Magness said.
With gas-fired generators hobbled by pipeline supply shortfalls and frozen instrumentation, Magness added that efforts to bring those units back online will get easier as the weather forecast improves. "The work that needs to be done to get those resources back in place is going to be easier to do as the weather warms," Magness said.
Woodfin noted the grid operator's numbers have been "bouncing around" since the cold snap began because control room operators are utilizing generators "to the maximum amount possible" as soon as they become available.
Capacity, winterization concerns
Magness was also asked to respond to comments made by Texas Gov. Greg Abbott to a Houston TV station suggesting that ERCOT leadership should resign over the state's widespread outages.
"I will say that the fundamental decision that was made in the middle of the night at 1 a.m. on Monday to have outages imposed was a wise decision by the operators that we have here," Magness said.
If ERCOT had not ordered load shedding at that time, Texas may have faced a statewide blackout lasting "months," Magness said.
Magness also pushed back on the idea that the current outages could have been avoided if ERCOT switched from an energy-only market with high scarcity pricing to a design featuring a mandatory capacity market like those operated by the ISO New England, New York ISO, and PJM Interconnection.
"I don't think a capacity market would have changed the weather," Magness said. "I don't think there was a capacity shortage, it was a problem with that capacity being knocked out by an extraordinary event."
Woodfin was also asked if ERCOT could have done more to ensure generators were sufficiently weatherized after a similar cold snap in February 2011 knocked out power for millions of customers in Texas and Arizona. Following that event, the Federal Energy Regulatory Commission and North American Electric Reliability Corp. issued a set of best practice guidelines for winterizing generators located in southern states.
In Texas, Woodfin said, winterization plans are filed with the state Public Utility Commission and then ERCOT performs annual spot checks for about 100 generators out of the roughly 600 generating facilities on its system.
Those best practices proved successful during another winter storm in 2018, Woodfin said, "but apparently were not sufficient" to keep generators online during even more extreme cold experienced over the last few days.
"I guess the other piece of the question was that those were not mandatory," Woodfin said. "They were voluntary guidelines for individual generation companies."