Texas may have come closer to rolling blackouts earlier this month than was previously thought, according to a briefing by Electric Reliability Council of Texas officials at the Texas Public Utilities Commission on Thursday.
On September 6, the Electric Reliability Council of Texas (ERCOT) issued an appeal urging electricity users to voluntarily conserve power from 6-9 p.m. However, at 7:25 p.m., ERCOT announced that it had moved into Energy Emergency Alert Level 2 (EEA2) operations, indicating that conservation had become critical to maintaining the grid. The EEA2 lasted about an hour before ERCOT returned to normal operations.
The emergency alert was initiated due to a drop in the grid’s energy reserves and frequency, which “must be maintained between 60.1hz and 59.9hz at all times,” according to an ERCOT press release. The frequency is an important indicator of the grid’s health. The grid operator issues an EEA2 when operating reserves are below 1,750 megawatts with no expected recovery within 30 minutes.
“There was no headroom left, and so in order to find some headroom, we went into EEA2,” ERCOT COO Woody Rickerson told commissioners at the September 14 meeting, per Fox 4 KDFW.
The emergency declaration allows ERCOT to access “additional power sources only available during emergency conditions to protect the reliability of the electric system,” the organization explained in the press release. ERCOT attributed the deficit in energy reserves to a combination of factors, including elevated temperatures, high demand, and low solar and wind power reserves.
In addition, officials revealed at the Public Utilities Commission (PUC) meeting that a transmission problem prevented wind-generated electricity from southern Texas from reaching portions of the grid in the northern part of the state, Fox 4 reported.
With the benefit of hindsight and further review of the situation, ERCOT officials said they believe the available reserves during the emergency alert were even less than they had initially assessed.
“We are looking for why it might not have been accurate,” Rickerson told the commissioners, according to Fox 4. “There are several possible reasons, but we’re waiting to see what that report says before we speculate what caused that.”
PUC Commissioner Jimmy Glotfelty commented on his belief that gas and coal outages in the northern part of the state contributed to the emergency situation.
“I think there is a big discussion that’s missing on the thermal outages in the north,” said Glotfelty, per Fox 4. “…[F]rom conversations I’ve had with you all at ERCOT, that was one of the reasons this transmission line became overloaded.”
During August and September, ERCOT issued voluntary conservation requests 10 times, and Rickerson advised PUC members that such requests could become the norm.
He explained that conditions such as solar power deficits and tight reserves during evening hours will likely be observed in the future. He said tight conditions can also be expected during morning hours this winter.