Just under half of Texas’ power generation, or 53.3 out of more than 100 gigawatts, was forced offline at one point during the cold snap that swept through Texas this month, the head of the state’s power grid operator said during a meeting of its board on Wednesday.
The statistic was one of several eye-popping figures to emerge from an initial post-mortem of the Texas fiasco delivered by Bill Magness, the chief executive of the Electricity Reliability Council of Texas (ERCOT), the grid operator.
ERCOT has come under pressure in recent days over the rapid-fire actions it took to preserve the grid. The parents of an 11-year-old who died of hypothermia have filed a lawsuit targeting the agency. And many smaller power and gas companies, as well as a number of households, are furious that they were forced to pay exorbitantly high prices to continue accessing energy during the worst of the storm.
But Magness stressed in the meeting that the consequences would have been far worse if ERCOT had not taken rapid emergency actions, which included deliberately cutting power demand from the grid to avoid causing a blackout that might have lasted weeks or longer.
“It would be a much more devastating situation for Texans,” said Magness. “We might still be here today talking about when is the power going to come back on.”
As the Arctic blast pummeled the typically warm-weather state during the night of February 14th and early in the morning of February 15th, pipelines froze, natural gas couldn’t flow to gas power plants, and ice clung to wind turbine blades.
As growing numbers of power plants failed in the middle of the night, ERCOT staff called up facilities around the state to ask them to “shed” load — or disconnect electricity demand from the grid — in order to help preserve the grid’s integrity. If demand on the grid significantly exceeds supply for even a few minutes, key infrastructure can fail entirely, a far more serious situation even than the one that actually occurred.
The maximum amount of load ERCOT requested to be shed at any given time was 20 gigawatts, or five times the amount that it requested offline in a less severe episode a decade ago in 2011. That amount was “dramatically larger than anything we’ve ever seen at ERCOT,” said Magness.
The largest single source of power outages came from gas turbines, although wind turbines, coal plants and even one nuclear power plant failed at various points as well. Magness estimated that, of the natural gas capacity that failed, around half may have been caused by instrumentation issues and around half from issues related to the failure to procure natural gas fuel.
The scale of the power outages far surpassed that of an earlier cold weather power crisis from 2011, which has drawn some comparisons. Back then a cumulative 193 generators went offline, dwarfed by this month’s total of 356 generators forced offline.
The earlier 2011 cold weather episode prompted the Public Utility Commission of Texas, which oversees the grid operator, to review the preparedness of the grid in the face of extreme cold weather events. Although it now recommends that power plants weatherize their infrastructure, there is no requirement to do so. Magness said that ERCOT performs weatherization checks of some generating facilities, but it does not have the ability penalize units that aren’t taking measures to guard against the cold.