A problem with the power grid itself knocked about 1.26 gigawatts of generation offline at the peak of the crisis, potentially exacerbating the energy woes. About 2% of outages that week were caused by an unexpected dip in frequency — or the flow of electricity on the grid — according to a survey of power suppliers released Tuesday by the Electric Reliability Council of Texas, which manages most of the state’s power system.
The finding is significant because the grid operator, known as Ercot, has continued to assert that the dip didn’t compound the outages by forcing plants offline. Maintaining frequency at around 60 hertz is critical to keeping the system stable, and is one of Ercot’s key responsibilities. The frequency fell as low as 59.3 hertz on Feb. 14, the first day of the blackouts, according to Bloomberg data. Ercot operating protocols say a deviation of 0.2 hertz “for a long period” could cause damage to generators and customer equipment.
Power providers Vistra Corp., Calpine Corp. and NRG Energy Inc. have all said they lost generation due to the frequency plunge, with NRG President Mauricio Gutierrez telling Texas lawmakers in February that the dip “threatened the majority of the fleet.”
Ercot didn’t immediately respond to a request seeking comment.