U.S. grid operators performed reliably through arctic cold weather this winter, implementing lessons learned from recent extreme weather events, according to a new joint report from both the Federal Energy Regulatory Commission and the North American Electric Reliability Corporation.
The report, January 2025 Arctic Events: A System Performance Review, compared January’s uninterrupted grid operations to system performance during prior extreme events. Those include Winter Storm Uri in 2021, which caused rotating outages in the Electric Reliability Council of Texas (ERCOT), and Winter Storm Elliott in 2022, which resulted in rotating outages in the Midcontinent Independent System Operator (MISO).
The report recounts considerably improved performance across the industry in the face of challenging sub-freezing conditions. The week of Jan. 19 to Jan. 25 this year, for example, was the third coldest winter week across the U.S. since 2000, although temperatures did not drop as abruptly as during previous events, such as Winter Storm Elliott.
Key takeaways from the report include:
- Improved performance by generators in winter conditions
- Increased communication and coordination for expanded situational awareness among all sectors
- Implementation of lessons learned from prior extreme weather
- Adequate fuel supplies provided by the natural gas system despite some production limits
Uninterrupted Service Despite Record Demand
Unit commitment practices ahead of severe weather have become common since Winter Storm Uri for grid operators and load serving entities, such as the Southwest Power Pool (SPP), ERCOT, PJM and the Tennessee Valley Authority (TVA), the report noted.
In a similar vein, operators also continued their practice of postponing maintenance on equipment to bring more units into service. Ahead of severe weather this past winter, PJM anticipated limited natural gas supplies over the Martin Luther King Jr. Day holiday weekend and prescheduled certain natural gas units to encourage secure fuel supplies in advance of approaching Winter Storm Enzo, the report noted.
PJM’s decision to declare Conservative Operations in advance of the storm enabled generators to obtain gas supplies from Saturday, Jan. 18, through the following Wednesday, Jan. 22, when PJM recorded a new winter peak load record of approximately 145,000 MW. Other service areas also recording new peak records this January were MISO South, TVA and the Virginia-Carolinas Reliability Group South.
Improved Load Forecasting
Grid operators across the U.S. reported improved accuracy in forecasting electricity demand compared to prior events, with an average forecast error of less than 3% when peak use was at its highest between Jan. 21–24. This was an improvement from double-digit forecasting errors in some cases during prior winter periods. For the duration of January’s arctic cold events, PJM’s load forecast, for example, ranged between 0.17% and 3.54% on Monday, Jan. 20 – an elevated percentage given holiday uncertainty around expected human behavior and businesses and schools being closed for the holiday.
Gas-Electric Industry Coordination
The performance of natural gas-fired generation improved during this winter’s extreme cold by combining storage and real-time production with better coordination and communication strategies. For example, interstate pipelines issued more proactive and frequent notices to customers and balancing authorities. Gas industry staff also participated more actively in situational awareness calls to convey critical insight into pipeline supplies and readiness.
The report noted that PJM’s Gas-Electric Coordination Team stepped up frequency of communications and meetings at times of greatest risk to the system. While industry advancements such as the creation of the industry’s Natural Gas Readiness Forum have assisted the flow of real-time information, more communications work is needed to improve transparency and shared knowledge, the report said.
Results like these demonstrate the tangible effects of real-world teamwork and progress made by the gas and electric industries, FERC Chairman Mark Christie said following the presentation of the report at the agency’s monthly meeting Jan. 17.
“This is an extraordinarily important report,” Christie said. “This is an important report about how you can make the grid reliable and the reality of what it took to do it.”
PJM’s Mike Bryson, Sr. Vice President – Operations, said the good news contained in the FERC/NERC report should not suggest that the work to improve winter reliability is complete.
“We need to make sure that the successes of this winter become part of our routine, and we build these lessons on reliability permanently and cost-effectively into our rules, procedures and approach,” Bryson said.
FERC Chair: PJM’s Historical Support for Neighbors Not a Given
As extreme weather approached, grid operators deferred, recalled or canceled transmission outages and focused on enhanced transfer capability. TVA returned a line to service to enable power transfer from PJM to points south. At maximum demand the morning of Jan. 22, PJM net exports averaged 7,650 MW to its neighbors, even as PJM recorded a new record winter peak load. These exports will dry up if PJM’s margins continue to tighten under increasing demand, the continued retirement of generators and the slow pace of their replacements coming online, Christie said. “PJM historically has been a power exporter. But that is because PJM has had surplus power capacity to export,” Christie said. “Those days are ending; as PJM loses its surplus generating resources, there won’t be anything to export.”