...the companies didn’t have flexibility to roll power from one area to another to spread out the pain.
The emergency procedures are designed to avoid overwhelming the entire Texas grid. If that had occurred, even as power generators recovered from the cold, ERCOT would have been unable to quickly reconnect them back to the grid, Johnson said.
Grid operators would have needed to slowly and carefully bring generators and customers back online, all the while taking care to not to cause more damage to the grid. It’s a delicate process, Johnson explained, because each part of the puzzle---the generators producing power, the transmission lines that move the power and the customers that use it---must be carefully managed.
“It has to balance constantly,” she said. “Once a grid goes down, it’s hard to bring it back online. If you bring on too many customers, then you have another outage.”
ERCOT officials have repeatedly said the winter storm that swept the state caught power generators off guard, and it previously appeared there was more than enough supply to meet demand. But the storm far exceeded what ERCOT projected in the fall to prepare for winter.
“The operators who took those actions to prevent a catastrophic blackout and much worse damage to our system, that was, I would say, the most difficult decision that had to be made throughout this whole event," Magness said.
Nine grid operators are working at any given time who make these sorts of decisions, said Leslie Sopko, a spokesperson for ERCOT.
“At the end of the day, our operators are highly trained and have the authority to make decisions that protect the reliability of the electric system,” she said in a statement.
ERCOT made “significant progress” overnight Feb. 17 to restore customer power to many Texans, and remaining power outages are likely due to ice storm damage to the distribution system. Some areas that were taken offline will also need to be restored manually, according to ERCOT.
ERCOT warned that emergency conditions remain, and that “some level of rotating outages” may be necessary over the coming days to keep the grid stable.