Almost two years after Winter Storm Elliott forced the largest recorded manual load shed in the history of the Eastern interconnection, the North American Electric Reliability Corp. said Friday it “remains concerned about maintaining sufficient natural gas supplies to address extreme winter conditions.”
NERC’s statement on the “criticality of natural gas supply this winter” follows other warnings the reliability watchdog has issued regarding the need for greater coordination between the gas and electric sectors. Grid operators and gas producers this week said they are heeding those warnings and are working to weatherize their systems and improve market mechanisms to keep energy flowing.
Temperatures were up to 30 degrees below normal during the December 2022 storm, driving electricity demand higher and causing grid operators to declare emergency operations. Unplanned outages reached 90,500 MW, and transmission operators in the Southeast ordered firm load shedding that exceeded 5,400 MW, NERC, the Federal Energy Regulatory Commission and grid operators concluded in a joint assessment of the event published a year ago.
Elliott marked the fifth event in the last 13 years where gas supply disruptions played a role in cold weather-related generation outages that jeopardized bulk power system reliability, NERC said. And heading into this winter, some weather forecasts are calling for a colder-than-average December across much of the U.S. northern tier.
Elliott was “by no means an isolated example of the link between natural gas supply and electric reliability,” NERC said.
“As the electric system increasingly relies on natural gas, more gas infrastructure, including pipelines and storage, is needed to enhance deliverability,” NERC said. Supply disruption “was a central cause of generator failures that led to load shedding,” with cold temperatures resulting in declines in gas wellhead production and other system impacts.
The joint report on Winter Storm Elliott concluded that gas fuel supply issues accounted for 20% of unplanned generating unit outages, derates, and failures to start. Not all of those outages resulted from physical issues, however. The report also pointed to problems with scarcity pricing, mismatches between the timing of the gas and electricity markets, and pipeline scheduling constraints.
Since Elliott, gas operators have been working to weatherize pipelines, wellheads and other infrastructure. And grid operators say they are adjusting their planning processes and protecting their systems against extreme weather.
The Natural Gas Supply Association, representing gas producers and marketers, in a Sept. 4 fact sheet, said its members are taking a “multitude of proactive measures” to prepare for the winter, including “stringent self-inspections prior to anticipated weather conditions,” assisting customers in finding alternative market options, and mitigating weather exposure with “additional supplies and enhanced protections.”
“We operate winter continuity programs that help protect upstream facilities and field personnel during winter events, improving our ability to maintain operations during extreme conditions,” NGSA said.
Grid operators focus on weatherization, market mechanisms
The Midcontinent ISO “is currently conducting the annual winter readiness surveying cycle,” Brandon Morris, a spokesperson for the grid operator, said in an email. MISO’s territory covers 15 central U.S. states and the Canadian province of Manitoba.
“We are focused on sending the right market signals to highlight the value of resource availability and incentivize generation owners to have firm access to fuel, especially during tight operating conditions,” Morris said.
MISO faces a possible capacity shortfall in some regions beginning next summer, according to an annual report published in June.
The grid operator has recently implemented a “seasonal construct” for its annual planning resource auction to consider how much different resources bolster grid reliability during stressed periods, Morris said. “MISO will continue working with regulators, our member utilities, fellow grid operators and the natural gas industry to improve coordination with a focus on maintaining reliability,” he added.
New England uses natural gas to generate about half of the region’s electricity, “so we’re always focused on what’s happening on the gas system,” Matt Kakley, spokesperson for ISO New England, said in an email. “This is particularly true during the winter months, when supplies may be tighter due to heating needs.”
ISO New England, along with MISO, PJM Interconnection and the Southwest Power Pool, in February published a white paper on paths to improving the reliability of gas-electric coordination across their territories, including weatherization, permitting reforms and incentivizing firm gas transportation and storage for generators.
“There are significant differences in the level of scheduling flexibility available to generators to respond to [regional transmission organization] dispatch instructions, particularly during constrained system conditions,” the paper noted. The RTOs added that they “recognize that the degree of pipeline scheduling flexibility is heavily influenced by the degree of storage available on the system and the extent to which the pipeline is fully subscribed during peak conditions.”
The New England grid operator is conducting an analysis of the upcoming winter, “but [we] are not anticipating any levels of concern greater than recent years,” Kakley said. “We agree with NERC’s sentiment that close coordination between the gas and electric sectors is vital to reliable operations.”
The Electric Reliability Council of Texas is conducting weatherization inspections of generating and transmission facilities, “being more transparent in grid operations, and continuing ERCOT’s conservative approach to operations,” the grid operator said in a statement.
Since 2021, ERCOT has taken a “reliability-first approach to grid operations, bringing generating resources online early to mitigate sudden changes in generation or demand,” it said in a statement. “ERCOT will continue to use all operational tools available, including implementation of programs, as well as executing legislative reforms (like summer and winter weatherization inspections).”
