Grid operator PJM and its transmission and generation owners said they maintained reliability of the electric system during the strongest sustained cold period that the PJM system has experienced since the 1990s, because of proactive communication and coordination that helped maximize generator and transmission availability and performance.
PJM operations and markets staff briefed stakeholders on performance of the system last month and into February at the operating committee on Feb. 5.
The weather brought multiple days of extreme cold, record or near-record electricity demand, and significant stress across both the electric and natural gas systems. From Jan. 16-21, temperatures across the PJM footprint stayed below freezing. This was followed by Winter Storm Fern, which brought snow and ice, as well as a round of more severe arctic weather for Jan. 23-Feb. 2.
PJM and its members were able to call on sufficient generation to cover reserves, serve electricity demand and provide enough exports to keep neighboring grids stable during Fern and the storm’s aftermath. Through close collaboration with generation owners, the grid operator said PJM was able to manage oil fuel inventory; with the aid of an order from the Department of Energy, dispatchers, in limited circumstances, were able to call on generators that would have been otherwise restricted; and the transmission system performed strongly.
Temperatures during the heart of the arctic wave from Jan. 26-30 came in significantly warmer than widely accepted forecasts, and school, government and office closings drove down electricity demand further. Because of those factors, PJM did not reach any record peaks, but still experienced hourly winter peak loads of 130 giga watts (GW) and above for eight consecutive days (from Jan. 26–Feb. 2, a first for the winter season). That included two of the top 10 hourly winter peaks in PJM history on Jan. 29 (139,046 GW) and Jan. 30 (138,479 GW), according to preliminary figures.
A key challenge during the event was the misalignment of gas and electric markets. PJM had to secure gas supplies the morning of Friday, Jan. 23, through the morning peak demand of Tuesday morning, Jan. 27. Forecasts at that point predicted four straight days of potentially record-setting electricity the following week.
Tight gas supplies and inflexible gas scheduling meant that PJM had increased operational costs and required PJM to take additional actions to preserve reliability during the highest-risk periods. These actions cost approximately $798 million in out-of-market “uplift” costs from Jan. 24-Feb. 1, according to preliminary figures.
Generator performance was at once relatively stable but also below near-term expectations, and higher than expected in seasonal winter projections, which forecasted 15.9 GW of expected outages during peak conditions.
During Winter Storm Fern and its aftermath, the PJM generation fleet experienced an average of 18-19 GW of outages. Plant equipment failures were by far the most commonly cited cause. During the January 2025 cold spell, where PJM set a winter peak record of 143.9 GW hourly demand, outages were around 12-13 GW through most of the event.
PJM said storm- and cold-related transmission outages were minimal and the system performed well.
