The North American Electric Reliability Corporation (NERC) this week said a recent study of the natural gas system in the northeast U.S. highlights “severe threats” to electric reliability in the region.

The study by the Northeast Power Coordinating Council (NPCC), initiated in 2023, focused on gas supply and pipeline constraints during extreme winter weather in New York and New England across three forecast periods: 2024-25, 2027-28 and 2032-33.

Both ISO-NE and NYISO expect to be dependent on natural gas for electric grid reliability over the study period. While gas generators may be burned less often as renewables and energy storage increasingly come online, the region’s fleet of gas-only and dual fuel generation resources will be relied on to both ramp and cycle to ensure grid reliability.

The region’s natural gas infrastructure is nearly fully utilized during extreme cold weather, limiting gas availability and increasing reliance on oil-fired generation to ensure electric reliability, the NPCC study found. During milder weather, pipelines can accommodate ramping needs. However, certain events, like pipeline disruptions and protracted extreme weather, could pose major threats to reliability.

LNG from terminals Constellation EMT and Repsol Saint John plays a critical role in supplementing gas supplies during harsh conditions, but their contributions are not interchangeable due to location-specific benefits, NPCC said. The retirement of oil plants and the potential loss of Constellation EMT could create reliability challenges in New England, necessitating capacity deficiency actions, the study found.

Further, LNG scheduling flexibility is hindered by insufficient financial incentives for generators and import facilities to secure supply contracts in advance of extreme weather. Structural reforms by ISO-NE could address this issue by improving market signals to enhance grid resilience, according to study findings.

In New York, dual-fuel generation is more common, and oil is heavily relied upon during cold weather contingencies, given gas infrastructure limitations. Electrification of heating and transportation will further increase gas demand, stressing both gas and electric systems in the long term.

Uncertainty around renewable energy deployment, especially offshore wind, could heighten performance demands on thermal generation, NPCC said. The council said both ISO-NE and NYISO must balance grid resilience, decarbonization goals and incentives for gas and dual-fuel generators to maintain operational flexibility.

“NPCC’s report is a sobering assessment and yet another call to action in a region that is running close to the edge,” said Jim Robb, NERC president and CEO. “During winter extremes, the electric system in the Northeast is dependent upon reliable natural gas supply. When rare, but well-observed contingencies occur, reliability is gravely threatened. This untenable situation cannot be mitigated solely by electric system operators, calling out the urgent need for tight operational and planning coordination between the two sectors.” 

NCPP also noted that despite growing dependence on natural gas, pipeline expansions in the region have been minimal, leading to persistent winter bottlenecks and frequent critical notices from pipelines.

Local distribution companies primarily hold firm transportation entitlements, the council said, while generators rely on third-party contracts or non-firm capacity. The study emphasized the impact of gas scheduling restrictions on generation availability during peak heating season disruptions.

Read NCPP’s full study here.