WASHINGTON, D.C. — Recent comments by MISO’s Independent Market Monitor at the Federal Energy Regulatory Commission’s Reliability Technical Conference on resource adequacy asserted certain data discrepancies in the MISO area in NERC’s 2024 Long-Term Reliability Assessment, which resulted in the understatement of resource availability. Following an in-depth review, NERC found that MISO submitted mismatched data, which overstated the near-term energy shortfall risk. When reanalyzed with the corrected data, the MISO footprint was reclassified as an “elevated risk” over the next few years, shifting to “high risk” in the 2028–2031 timeframe, depending on new resource additions/retirements. Elevated risk areas meet resource adequacy criteria; however, under extreme weather conditions these areas are likely to experience a shortfall in reserves. There was no impact on the recently released 2025 Summer Reliability Assessment, which analyzes different data.
While this data mismatch went unnoticed by MISO and the Midwest Reliability Organization (MRO) that initially collects and vets the data, NERC is ultimately responsible for ensuring the accuracy of its independent reliability assessments and is working to improve its review process. Currently, the control process calls for extensive checks by submitting entities and the Regional Entities as well as peer review by the Reliability Assessment Subcommittee. Going forward, NERC, MRO and MISO are all committed to improving the data validation process to ensure accuracy. A corrected version of the 2024 LTRA will be posted soon.
NERC is proud of its independent, continent-wide reliability assessments and regrets this discrepancy. We are pleased that our reports help focus the national discussion on reliability. NERC is committed to ensuring its independent assessments provide accurate, actionable information to industry, policymakers and our U.S. and Canadian stakeholders.
