Winter Storm Elliott, which swept through most of the United States during the Christmas holidays, exposed the vulnerability of the energy system as natural gas and power supplies were strained, wells froze off, and utilities vastly underestimated the power demand during the huge storm.
Despite the fact that it wasn’t as prolonged as the Winter Storm Uri of February 2021, when millions in Texas lost power for days, the latest storm showed—once again—that energy providers couldn’t accurately predict the power demand surge, and some had to resort to rotating outages to maintain grid stability. Moreover, well freeze-offs led to a plunge in natural gas production in the key gas-producing basin, the Appalachia, sending lower volumes via pipelines to gas-fired power generation units and sending regional natural gas prices soaring along with it.
Less than two years after the February 2021 storm, the latest deadly storm highlighted the fact that the gas systems and grids need to be better prepared for extreme weather events.
Winter Storm Elliott cut off the power supply to millions of households and disrupted Christmas travel plans for millions more as thousands of flights were canceled. Just ahead of the Christmas holiday weekend, almost 250 million U.S. and Canadian residents were affected by the storm in one way or another, and dozens of people have died.
While the Texas power grid managed to avoid catastrophic failures during the storm, the Electric Reliability Council of Texas (ERCOT) underestimated power demand.
“ERCOT is keeping up with demand, but it looks like ERCOT way underestimated how much power Texans would use in the freeze. They were off by about 10,000 megawatts tonight – enough electricity to power 2 million homes,” Houston Chronicle’s Shelby Webb said on December 23.
ERCOT also received approval from the U.S. Department of Energy to pollute more than typically allowed if grid conditions worsen and the system had to rely more on dirtier fuel oil burning instead of natural gas. In the letter asking for emergency approval to bypass emissions standards, cited by Houston Chronicle, ERCOT’s chief executive Pablo Vegas wrote that there were about 11,000 megawatts (MW) of outages among generators using coal and natural gas as fuel, 4,000 MW from wind generators and 1,700 MW of solar capacity.
Texas managed to avoid rolling blackouts, but power providers in other states implemented planned interruptions to manage the surge in power demand during the storm.
The Tennessee Valley Authority said early on December 24 that the rolling blackouts were “needed to maintain grid stability for 10 million people across seven states.”
In the Carolinas, Duke Energy concluded emergency rotating outages on the 24th of December and asked consumers to continue to conserve energy without sacrificing safety.
North Carolina Governor Roy Cooper said on Monday, December 26, that “Duke Energy assures me NC is in the clear now.”
“But I’m deeply concerned about people who lost power and who didn’t get notice about rotating outages. Grateful for those who conserved energy. I’ve asked Duke for a complete report on what went wrong and for changes to be made,” Governor Cooper added.
PJM Interconnection, which operates the massive grid from Illinois to New Jersey, declared a rare system-wide emergency. At the Stage 2 emergency, the grid operator told customers who had agreed to curb power use in extreme events to do so during the Christmas weekend.
Commenting on the vulnerability of the energy systems in the U.S., Michael Webber, an energy resources professor at the University of Texas in Austin, told Bloomberg, “Though the variability of wind and solar are well known and discussed a lot, these freezes also show the flimsiness of the gas system.”
