PJM Review: System Performed Well During Winter Storm Gerri

PJM and Member Actions Reflect Lessons Learned from Winter Storm Elliott


A preliminary review of system operations during Winter Storm Gerri Jan. 13–18 revealed strong generator and transmission performance, accurate load forecasting, and successful coordination with other regions.

PJM served a peak load of 134,777 MW at 8:10 a.m. Jan. 17, at the depth of the frigid weather that swept from the western part of the PJM region through to the East Coast, said Dave Souder, Executive Director – System Operations, in a presentation (PDF) to the Markets & Reliability Committee Wednesday.

More details will be discussed at upcoming February meetings of the Market Implementation Committee and Operating Committee, Souder said.

Souder began his presentation by thanking generation and transmission owners for their solid performance and close coordination, and noted that PJM implemented only a limited set of emergency procedures to handle system stress, including: 

  • Cold Weather Advisory, Western Zone, Jan. 14–22
  • Cold Weather Alert, Western Region, Jan. 14–17 and Jan. 19–22
  • Conservative Operations, Jan. 13–17
  • NERC Transmission Loading Relief Level 1, Jan. 17

Natural gas generation in particular showed improved performance from Winter Storm Elliott in December 2022, due in part to fewer outages from the gas production and transportation sectors. At its peak, the forced outage rate during the recent cold weather was 16,119 MW; outages during Elliott reached as high as 46,000 MW. Souder noted that the extreme low temperatures during Winter Storm Gerri did not impact the entire PJM footprint, as they did during Elliott.

Souder said fewer well freeze-offs and limited pipeline disruptions allowed for consistent gas supply, and the PJM Gas-Electric Team maintained continuous communication with the pipeline control centers to monitor and share operating conditions and forecasts.

PJM’s forecasts of electricity demand, or load, were consistently within 3% of the actual peak load, and the number of generator outages matched anticipated outage levels. Throughout the week, PJM exported anywhere from 5,000 MW to 12,000 MW, with an average of approximately 8,000 MW, to neighboring systems, Souder said. During the coldest periods, Souder said, PJM’s exports represented nearly 10% of its own needs.

Souder credited the improvements in part to lessons learned from Elliott, including cold-weather preparations by generation owners and PJM’s action to put units on the system earlier. Over 400 generators reported making winterization improvements, Souder said.

Brian Chmielewski, Sr. Manager – Real-Time Market Operations, provided a high-level review from a markets perspective.

Real-time pricing peaked coincident with system conditions Jan. 16–18, driven by load, interchange and localized congestion, Chmielewski said.

The system experienced one synchronized reserve event on Jan. 13, but it was less than 10 minutes. Localized congestion peaked on Jan. 17.

Chmielewski estimated uplift at $47 million through Jan. 17.

Souder and Chmielewski took feedback from stakeholders and will be providing more details at upcoming meetings.

Current conditions can be viewed on the Markets and Operations Dashboard and on the PJM Now application.