NERC Winter Report Says Extreme Cold Weather Could Cause Reliability Shortfalls

by APPA News
November 29, 2021

Certain regions of the country, particularly those vulnerable to extreme weather, natural gas supply disruptions and low hydro conditions, are at risk for electricity supply disruptions this winter, according to the North American Electric Reliability Corp. (NERC).

In its 2021–2022 Winter Reliability Assessment, NERC advises the industry to prepare by taking steps for generator readiness, fuel availability and sustained operations in extreme conditions.

Although anticipated reserve margins meet or surpass the NERC’s margin levels in all areas, the organization warned that “extreme or prolonged cold temperatures over a large area could create “unique challenges in maintaining grid reliability in many parts of North America.”

Responses NERC solicited from grid stakeholders indicate that they have taken preparations to enhance reliability during cold weather events, but “some plant vulnerabilities can be anticipated for the upcoming winter.”

To reduce the risk of shortfalls, NERC is recommending:

• Grid operators and generator operators review NERC’s Level 2 cold weather alert and take the recommended steps prior to winter;
• Grid operators should prepare their operating plans to manage potential supply shortfalls and take steps for generator readiness, fuel availability, and sustained operations in extreme conditions. And balancing authorities should poll their generating units in advance of approaching severe weather to assess their readiness for normal and extreme conditions;
• Balancing authorities and reliability coordinators should conduct drills on alert protocols, and balancing authorities and generator operators should verify protocols and operator training for communications and dispatch;
• Distribution providers and load-serving entities should review non-firm customer inventories and rolling black out procedures to ensure that no critical infrastructure loads such as natural gas or telecommunications would be affected and rehearse protocols that prepare customers for the impacts of severe weather.

“To be resilient in extreme weather, we are counting on our grid operators to proactively monitor the generation fleet, adjust operating plans and keep the lines of communication open,” Mark Olson, manager of reliability assessments at NERC, said in a statement.

NERC referenced last February’s cold weather that caused outages in Texas and other states, and said that peak demand or generator outages that exceed forecasts, such as have occurred in previous winters, “can be expected to cause energy emergencies” in the Midcontinent Independent System Operator (MISO), Southwest Power Pool (SPP), and Electric Reliability Council of Texas (ERCOT) regions.

While both New England and the Southwest have sufficient planning reserves, NERC warned that fuel supplies to generators in those areas can be vulnerable during cold weather conditions.  NERC also highlighted New England and California for their vulnerability to weather related natural gas supply disruptions. Specifically, Southern California and the Southwest have limited natural gas storage and lack redundancy in supply infrastructure, so generators there also could face fuel supply curtailment or disruption from extreme winter weather.

In New England, the capacity of natural gas transportation infrastructure can be constrained when cold temperatures cause peak demand for both electricity generation and consumer space heating needs, exacerbating the risks for fuel-based generator outages and reductions, NERC noted.

In the Pacific Northwest, resources are sufficient but higher demand from extreme temperatures could cause shortfalls, particularly if the region’s drought continues and causes low hydro conditions, reducing electricity supply for transfer throughout the area, NERC warned.