By Leland McMillan, Supervisor NERC Services
and Carl Curry, NERC Reliability Specialist
NERC Standards are aimed to increase electric reliability, but the one major component that is outside NERC’s jurisdiction is natural gas supply. NERC issued a statement in September 2024 indicating that fuel supply was a contributing factor for past winter events. The NERC document offered the following summary:
On December 23–24, 2022, Winter Storm Elliott gripped the eastern United States, with low temperatures that were 15 to 30 degrees below normal. Temperature extremes precipitated a sharp spike in peak electricity demand, driving energy emergency declarations by many grid operators. During the event, unplanned generation outages at one point totaled 90,500 MW, equivalent to 13% of the resources in the U.S. Eastern Interconnection. To maintain grid reliability over the course of the storm, transmission operators in the Southeast ordered firm load shedding at various periods that exceeded 5,400 MW in total. It was the largest recorded manual load shed in the history of the Eastern Interconnection.
Natural gas supply disruption was a central cause of generator failures that led to load shedding. The extreme cold conditions caused major declines in natural gas wellhead production, with additional impacts to processing activity, challenging the gas system’s ability to meet demand from electric generation and home heating. Natural gas production declined most significantly in the eastern United States—in the Marcellus and Utica Shale formations—where production dropped by 23 to 54%. The Elliott report found that natural gas fuel supply issues accounted for 20% of unplanned generating unit outages, derates, and failures to start. Details can be found in the FERC/NERC/Regional Entity staff report on Winter Storm Elliott.
Other historical events have seen gas supply shortages contribute to electric reliability issues as NERC summarizes in this table:
(source: https://www.nerc.com/news/Headlines%20DL/Natural%20Gas%20Statement_12SEP24.pdf)
Solutions are being investigated but require coordination across the states and different federal agencies. NERC identifies that “The natural gas industry is making encouraging progress on commercial practices and has made voluntary commitments to improve winter preparation. Efforts such as the North American Energy Standards Board (NAESB) Forum report continue to prompt positive action. NARUC has launched its GEAR Taskforce with results expected later this year or by early next year. For its part, NERC continues to collaborate extensively with industry and policymakers. NERC has enhanced its Reliability Standards to better prepare generators for winter extremes, implement training, and establish communication protocols between generators and grid operators. Current standards projects encompass extreme weather planning and energy assurance requirements. NERC and NPCC are jointly studying the Northeast gas system, with results anticipated later this year. NERC remains committed to continued collaboration on this critical interdependency.”
Another storm event listed above, Winter Storm Uri, impacted the ERCOT grid and demonstrated the interdependence between power producers and natural gas suppliers. As the temperatures dropped and stayed at record lows for several days, generator outages became more widespread, with 48.6% of generation unavailable at one point during the storm. Later studies showed that natural gas supply was becoming an increasing problem during the winter storm, and as transmission operators initiated rolling blackouts to stabilize the grid they were at times unknowingly cutting power to parts of the natural gas supply chain. The loss of power aggravated the fuel supply problem and as a result natural gas producers were not able to deliver enough fuel to power plants. Another contributing problem were some wells and facilities had problems of their own due to the freezing conditions.
The initial action taken to correct the energy problems experienced during winter storm Uri was to create additional winterization requirements to generating plants; however, Texas also enacted legislation requiring the collaboration between electric and oil & gas agencies. This legislation provided additional measures to address the natural gas side of the equation. Oil and gas operators are now required to comply with more winterization preparation measures which had not been in place before. Also, oil and gas operators that meet reporting criteria must now file with the Texas Railroad Commission each year certifying they have provided their customer information to their electric utility. This information will allow electric utilities to prioritize providing service to critical natural gas facilities during an energy emergency event.While the regulators are coordinating solutions, it is prudent for applicable generation entities to consider natural gas as critical to their operations this winter and take actions to ensure that sufficient fuel supply is available for operations in all conditions.
While the regulators are coordinating solutions, it is prudent for applicable generation entities to consider natural gas as critical to their operations this winter and take actions to ensure that sufficient fuel supply is available for operations in all conditions.
(source: https://www.ercot.com/files/docs/2021/03/03/Texas_Legislature_Hearings_2-25-2021.pdf)