The North American Electric Reliability Corporation’s 2025–2026 Winter Reliability Assessment finds that much of North America is again at an elevated risk of having insufficient energy supplies to meet demand in extreme operating conditions.
Although resources are adequate for normal winter peak demand, any prolonged, wide-area cold snaps will be challenging, NERC said. This is largely due to rising electricity demand, which has grown by 20 GW since last winter, significantly outpacing winter on-peak capacity. This, coupled with the changing resource mix, is affecting the winter outlook.
“Electricity demand continues to grow faster than the resources being added to the grid, especially during the most extreme winter conditions where actual demand can topple forecasts by as much as 25%--as we saw in 2021 in ERCOT and SPP,” said John Moura, NERC’s director of Reliability Assessments and Performance Analysis. “This latest assessment highlights progress on cold weather readiness but underscores that more work remains to ensure energy and fuel supplies can be reliably delivered even during the harshest conditions.”
Although evidence from the past two winters indicates notable improvement in the delivery of natural gas to bulk power system generators, natural gas availability for generators remains precarious during extreme winter conditions due to the uneven application of voluntary freeze protection mitigations impacting production and transportation, NERC said.
“Natural gas is an essential fuel for electricity generation in winter. Winter fuel supplies for thermal generators must be readily available during the periods of high demand for both electricity and natural gas that accompany extreme cold weather ,” said Mark Olson, NERC’s manager of Reliability Assessment. “Although we are seeing evidence of improved performance, grid operators in areas that rely on single-fuel gas-fired generators are exposed to unanticipated generator loss during cold snaps when gas supply interruptions are more prevalent.”
NERC’s cold weather Reliability Standards address recommendations from winter storms Elliott and Uri reviews, it noted.
The most recent standard, EOP-012-3, became effective on October 1, 2025, among the improvements in the new version are enhanced and expanded requirements to ensure that Generator Owners (GO) implement corrective actions to address known issues affecting their ability to operate in cold weather in a timely manner.
This year’s assessment makes a series of recommendations to reduce the risks of energy shortfalls on the bulk power system this winter:
Cold Weather Preparations
Reliability Coordinators (RC), Balancing Authorities (BA), and Transmission Operators (TOP) in the elevated risk areas should review seasonal operating plans and protocols for communicating and resolving potential supply shortfalls in anticipation of potentially high generator outages and extreme demand levels. Operators should review NERC’s Resources on Cold Weather Preparations.
GOs should complete winter readiness plans and checklists prior to December, deploy weatherization packages well in advance of approaching winter storms, and frequently check and maintain cold weather mitigations while conditions persist.
Load Forecasting
BAs should be cognizant of the potential for short-term load forecasts to underestimate load in extreme cold weather events and be prepared to take early action to implement protocols and procedures for managing potential reserve deficiencies. Proactive issuance of winter advisories and other steps directed at generator availability contributed to improved reliability during cold weather events of the past two winters.
Fuel
RCs and BAs should implement generator fuel surveys to monitor the adequacy of fuel supplies. They should prepare their operating plans to manage potential supply shortfalls and take proactive steps for generator readiness, fuel availability, load curtailment, and sustained operations in extreme conditions.
GOs/Generator Operators of natural-gas-fired units should maintain awareness of potential extreme cold weather developing over holiday weekends and the implications for fuel planning and procurement that may result given the natural gas purchase close dates that precede long, holiday weekends.
Regulation and Policy
State and provincial regulators can assist grid owners and operators in advance of and during extreme cold weather by maintaining awareness of BA, natural gas pipeline, and gas local distribution company operational public announcements and notices, amplifying public appeals for electricity and natural gas conservation, and supporting requested environmental and transportation waivers.
Undertaken annually in coordination with the Regional Entities, NERC’s WRA examines multiple factors that collectively provide deep and unique 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.
