The North American Electric Reliability Corp. on Monday issued its highest alert level ever, urging generators and transmission owners to take measures to prepare for winter.
In its first Level 3 Essential Actions alert, NERC cited three “extreme winter weather events between 2018 and 2022. Severely cold winter weather knocked power plants offline in 2018 in the South Central U.S., in 2021 in Winter Storm Uri and last year in Winter Storm Elliott, leading to power shortages and outages, NERC said.
“When cold weather events such as Winter Storm Uri occur, system operators may need to shed firm customer load to prevent uncontrolled load shedding and cascading outages which may not only result in major disruption but also have very real human consequences,” the grid watchdog organization said.
The alert asks power plant owners to calculate the “extreme cold weather temperature,” or ECWT, for their generating units and include that number — the lowest 0.2 percentile of the hourly temperatures measured in December, January and February since 2000 — in their winter preparedness plans.
Generators should identify which units need additional freeze protection measures to operate at the ECWT and put them in place before the winter season if possible. Power plant owners also should identify critical components of their facilities and the steps they took to protect them from winter weather, according to the alert.
The alert calls on transmission operators to update their operating plan to include provisions such as minimizing the overlap of circuits that are designated for manual load shed and circuits that serve designated critical loads.
The operating plans should also include provisions for manual load shedding that can occur quickly enough to ease an emergency, according to the alert.
Balancing authorities, which maintain electric supply and demand in their areas, should update their operating plans to manage generating resources in their area to address various issues, including fuel supply and inventory concerns, and fuel switching capabilities, according to the alert.
Organizations won’t be fined for failing to implement the alert’s recommended actions, according to NERC.
The electric system is becoming more reliant on variable energy resources, such as wind and solar, and on natural gas, according to NERC.
“Extreme winter weather events have stressed the supply of traditional fuels and the dependability of new resources,” NERC said. “Preparation of resources for operation during extreme winter weather and situational awareness in both planning and operations by applicable registered entities is necessary for optimal reliability.”