According to the newly-released “2023–2024 Winter Reliability Assessment,” published by the North American Electric Reliability Corporation (NERC), much of North America is again at an elevated risk of having insufficient energy supplies to meet demand in extreme operating conditions.

The areas identified as being at elevated risk extend over much of the eastern two-thirds of the continent. In these areas, although resources are adequate for normal winter peak demand, any prolonged, wide-area cold snaps will be challenging due to generator outages and fuel vulnerability, extreme levels of electricity demand, difficulties in accurate forecasting, and the risk of firm electricity transfer curtailments.

Undertaken annually in coordination with the Regional Entities, NERC’s Winter Reliability Assessments examine multiple factors that collectively provide insights into reliability risk. These factors include resource adequacy, encompassing reserve margins and scenarios to identify operational risk; fuel assurance; and preparations to mitigate reliability concerns.

“Extreme cold weather events can cause electricity demand to deviate significantly from historical forecasts,” says Mark Olson, NERC’s manager of reliability assessments. “Electricity demand in winter is closely tied to outside temperature. As electric heat pumps and heating systems become more prevalent, their combined effect on system demand is even more pronounced.” Olson adds that the growth of intermittent resources, like solar generation, on the distribution system significantly increases load forecasting complexity and uncertainty. “Once again, we strongly recommend that operators take the necessary steps to prepare for winter,” he says.

Since last year, according to the report, NERC and industry stakeholders have worked diligently to revise existing standards and introduce a new standard to assure power plants are adequately winterized and prepared for extreme cold temperatures. “We enter the winter season with new cold weather standards in effect, specifically aimed at improving winter preparedness and coordination between Generator Owners and Generator Operators and bulk power system operators,” says John Moura, NERC’s director of reliability assessments and performance analysis. Additional cold weather standards recently adopted by NERC’s Board have been filed for FERC approval.

This year’s assessment makes a series of recommendations to reduce the risks of energy shortfalls on bulk power system this winter that include:

1 – Cold Weather Preparations: Grid operators, Generator Owners and Generator Operators should implement the NERC Level 3 Essential Actions alert, Cold Weather Preparations for Extreme Weather Events III, and winter operating plans.

2 – Fuel: Reliability Coordinators and Balancing Authorities should implement fuel surveys and monitor fuel supply adequacy.

3 – Load Forecasting: Balancing authorities should anticipate potential for underestimating load in extreme cold and take early action to reduce the risk of reserve shortfall.

4 – State Regulators and Policymakers: State regulators and policymakers should support public appeal for reduced electricity and natural gas use and be prepared to handle requests for environmental and transportation waivers when needed for reliability.