Ohio’s power grid prepares for record winter electricity demand as reserve margins tighten across PJM footprint

Grid operators forecast a new winter peak as cold-weather risks remain

Ohio utilities and regional grid operators are preparing for winter electricity demand that could reach record levels, driven by extreme cold, rising overall load and a power system operating with slimmer buffers than in past years.

Much of Ohio is served by PJM Interconnection, the nonprofit operator of the high-voltage grid and wholesale power market spanning 13 states and Washington, D.C. PJM’s winter planning outlook for the 2025–2026 season projected a peak demand of about 145,700 megawatts (MW), a level that would exceed the prior winter record set during the January 2025 cold outbreak. PJM projected approximately 180,800 MW of operational capacity available to meet that peak under expected conditions.

Reserve margins are shrinking, leaving less room for error

While the projected capacity exceeds expected demand, PJM has also reported tightening reserve margins when accounting for expected generator outages, routine operating needs and scheduled exports to neighboring regions. For this winter, PJM projected a planning reserve margin of about 7,500 MW, down from 8,700 MW the previous year. Lower reserve margins do not indicate an immediate shortage, but they increase the likelihood that emergency procedures could be needed during less likely, high-stress scenarios such as prolonged subzero temperatures, widespread equipment problems, or fuel constraints.

• Peak demand can surge rapidly during severe cold as electric heating, industrial load and household usage rise simultaneously.

• Generator availability can decline in extreme weather if units experience freezing-related issues or fuel supply disruptions.

• Electric exports to neighboring systems may increase during regional cold snaps, raising the load PJM must serve.

Operational preparations focus on winter performance and coordination

PJM and member utilities have expanded winter readiness measures following recent cold-weather events that pushed the system close to its limits. Recent operational steps highlighted by the grid operator include generator testing ahead of cold conditions, earlier commitment of gas-fired generation, enhanced short-term load forecasting, and coordination to return key transmission facilities from maintenance when higher reliability is needed.

New cold-weather readiness standards for generators became effective in October 2025 under mandatory reliability rules developed by the North American Electric Reliability Corporation (NERC), the body responsible for setting and enforcing bulk-power reliability standards in North America under federal oversight. These rules require plant-specific winterization practices intended to reduce freeze-related failures.

Even with adequate resources under expected conditions, extreme winter scenarios can require emergency operating procedures, including instructions to reduce demand and additional commitments of available generation.

Ohio sits at the intersection of two major grids

Ohio’s grid picture is also shaped by neighboring systems. Parts of the broader Great Lakes region are served by the Midcontinent Independent System Operator (MISO), which has projected winter peak demand around 103 gigawatts (GW) with the potential to reach 109 GW under more extreme conditions. MISO recorded a winter peak of 108 GW on Jan. 21, 2025 during a major storm. The proximity of these large regional systems matters because power flows and emergency support can cross boundaries when weather affects multiple states at once.

For customers, the reliability message is increasingly tied to two realities: winter demand is rising, and the system has less spare capacity than it did when reserve margins were larger—making generator performance, fuel availability and rapid grid operations central to keeping power on during the coldest days.