Major storm poses biggest test for Texas grid since Uri killed 246
by Breanne Deppisch, Energy and Environment Reporter
December 22, 2022 05:00 AM
A powerful winter storm is unleashing dangerous weather across much of the United States this week, including Texas, where the single-digit temperatures and below-zero wind chill are expected to pose the biggest test of the state's power grid since the deadly 2021 Winter Storm Uri.
The National Weather Service has warned anyone in the storm’s path to be on high alert, describing it as a “once in a generation type event” expected to extend through the Lower 48.
Texas, it said, should be prepared for an “aggressive” arctic blast, which forecasters expect to bring frigid conditions and “dangerously low wind chills” as low as negative 15 degrees in parts of the state.
The warnings have left many wondering if Texas’s grid is prepared to endure this type of freeze. The state’s grid operator, the Electric Reliability Council of Texas, has been under intense scrutiny in the wake of Uri in February 2021, which caused 4.5 million Texans to lose power, some for as long as four days, and resulted in 246 deaths.
During the storm, ERCOT was forced to cut off consumers from the grid to help prevent a complete collapse. At the storm’s peak, ERCOT slashed 20,000 megawatts of load demand — the largest and longest controlled load shed event in U.S. history. (For context, just 1 MW of electricity is enough to power roughly 200 homes during peak demand.)
ERCOT insists it has taken the necessary steps to withstand demand during the freeze.
Regulators have remained cautiously optimistic, pointing to improvements such as the winterization of power plants and ensuring firm fuel supply services by generators in case of emergency. Texas also added 12 gigawatts of power to the grid — including 9 GW of solar and wind capacity, more than 1.9 GW of battery storage, and additional natural gas-fired generation.
“As we monitor weather conditions, we want to assure Texans that the grid is resilient and reliable,” ERCOT President and CEO Pablo Vegas said in a statement. “We will keep the public informed as weather conditions change.”
During a committee meeting Monday, ERCOT officials said 95% of facilities required to weatherize had sent in required “declarations of preparedness” before the storm. Officials were also actively inspecting facilities for compliance.
"We are better prepared than ever," Peter Lake, chairman of the Texas Public Utility Commission, which oversees ERCOT, told reporters last month. He also shot down the suggestion of power outages, telling reporters, "Absolutely, I expect the lights will stay on [this winter].”
Others aren’t so sure.
One major problem contributing to Texas’s grid shortfalls in 2021 was the failure of natural gas production, storage, and distribution facilities — in large part because the natural gas itself was frozen.
“You can have the nicest power plant out there, but if you can't get either coal or natural gas [on the generation side], it's just not going to run,” Travis Cooke, a managing director at the Dallas-based energy consulting company Alden Energy, said in an interview.
Another factor will be how long the storm lasts.
While the additional grid capacity and emergency gas supplies have put the grid in a slightly better position than in 2021, the emergency supplies can only last so long, Cooke said — roughly 36 hours in extreme winter conditions.
“Anything less than 36 hours, we should be in good shape,” he said. “But anything longer than that, I think, would be a concern.”
Though the actions ERCOT has taken since then are a step in the right direction, federal officials and analysts alike say they have only marginally improved the grid’s ability to withstand extreme winter events.
A Federal Energy Regulatory Commission assessment published in late October found that the Texas grid remains nearly as vulnerable to extreme winter conditions as it was last winter despite more than a year of work by Texas regulators.
In fact, the report found, consumer demand could exceed supply by 18,100 MW under a similar weather scenario to Uri — requiring a load shed just 2,000 MW shy of what was needed last winter to prevent the grid from collapsing.
"Basically, what [the federal energy commission] is saying is if we get weather conditions like in February '21, we would have close to a repeat of what happened," Doug Lewin, president of energy consulting company Stoic Energy, told the Austin Statesman.