PJM Releases Winter Storm Elliott Report


PJM has released its Winter Storm Elliott Event Analysis and Recommendation Report, which reviews the circumstances leading up to the December 2022 storm, assesses performance of the system during the event and identifies recommendations to help improve grid reliability.

The report (PDF) emphasizes that PJM maintained system reliability and served customers throughout the extreme weather that affected the region Dec. 23–25, and even was able to support its neighbors during certain periods. PJM operators were able to avoid electricity interruptions, although they had to implement multiple emergency procedures and issue a public appeal to reduce energy use.

“PJM was prepared for the 2022/2023 winter, as well as Winter Storm Elliott, based on the information available, and conducted extensive preparations and communications with members, adjacent systems and the natural gas industry in advance of the storm, in addition to the regular steps PJM takes each year to prepare for winter,” according to the report.

PJM’s annual pre-winter analysis indicated the system would have enough generation to meet load even under a combination of extreme and unlikely conditions, including pipeline disruptions, close-to-zero wind/solar generation, high outages and extreme weather. Despite numerous refinements to both the capacity market rules and winter preparation requirements since the 2014 Polar Vortex, “Winter Storm Elliott created a convergence of circumstances that strained the grid,” according to the report.

Elliott’s rapidly falling temperatures coincided with a holiday weekend, which combined to produce unprecedented demand for December. PJM’s load forecasts for Dec. 23 and Dec. 24 were approximately 8% under the actual peak. Recognizing the forecasting challenges presented by the volatile weather patterns and the holiday weekend, PJM operators scheduled prudently on both days, calling for generation resources in excess of the actual load and reserve requirements.

This situation was further complicated by the unexpected loss of generation resources. Most outages were caused by equipment failure, likely from the extreme cold, but broader issues of gas availability also added to the outage rate.

PJM’s analysis of its experience keeping the lights on throughout the storm for 65 million customers in 13 states and Washington, D.C., drives 30 recommendations contained in the report. The recommendations focus broadly on:

  • Addressing winter risk with enhancements to market rules, accreditation, forecasting and modeling
  • Improving generator performance through winterization requirements, unit status reporting and testing/verification
  • Tackling long-standing gaps in gas-electric coordination, including timing mismatches between gas and electric markets, the liquidity of the gas market on weekends/holidays, and the alignment of the electricity market with gas-scheduling nomination cycles
  • Evaluating how the Performance Assessment Interval (PAI) system of rewarding or penalizing generator performance is impacted by exports of electricity to other regions, whether excusal rules can be simplified, PAI triggers need to be refined, and if the contributions of Demand Response and Energy Efficiency are accurately valued
  • Pursuing opportunities with Generation Owners, other members and states to improve education, drilling and communication regarding PJM’s emergency procedures, Call for Conservation and PAIs

Many of these recommendations are being developed through the Critical Issue Fast Path – Resource Adequacy process or other forums, including the Electric Gas Coordination Senior Task Force, Operating Committee and Market Implementation Committee.

The report will be presented and discussed at the Winter Storm Elliott Report Workshop, 9 a.m. to noon on Monday, July 24 (please note that the workshop was originally scheduled for July 25 and has been moved up one day). Register for the workshop at the Markets & Reliability Committee page on PJM.com.