The Midcontinent Independent System Operator (MISO) and the Organization of MISO States (OMS) have released the results of the 2025 OMS-MISO Survey, which provides a five-year forecast of electricity resource adequacy across the MISO region. The report outlines a range of possible outcomes for the 2027/28 planning year, with projections varying from a 1.4 GW shortfall to a 6.4 GW surplus in Summer Accredited Capacity.
The survey also notes evolving seasonal risk patterns linked to the increasing presence of solar energy in the resource mix. Due to solar generation’s specific operational characteristics, reliability considerations are expanding beyond the traditional summer peak season.
“The annual OMS-MISO Survey is a valuable tool that supports ongoing planning and policy decisions,” said Joe Sullivan, president of the Organization of MISO States and vice chair of the Minnesota Public Utilities Commission. “The collaboration between OMS and MISO ensures stakeholders have access to shared insights that contribute to discussions about resource adequacy and the region’s changing energy needs.”
Key findings from the 2025 survey include:
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New Capacity from Queue Projects: Replacement and surplus queue projects are expected to offset some impacts of generator retirements, contributing about 25% of projected new capacity.
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Increased Demand Pressures: Economic growth, including data centers, reshoring of manufacturing, and industrial developments, is contributing to additional electricity demand in several areas.
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Ongoing Reliability Reforms: Recent changes — such as the implementation of a seasonal resource adequacy structure and the Reliability-Based Demand Curve — aim to improve the assessment of operational risks, particularly in the context of extreme weather and evolving resource portfolios.
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Future Accreditation Changes: The survey includes information on the anticipated transition to the Direct Loss of Load accreditation method, set to begin in the 2028/29 planning year.
“The survey underscores the importance of continued capacity planning as electricity demand grows,” said John Bear, MISO President and CEO. “MISO will continue to work with stakeholders to develop tools and processes that support long-term system reliability.”
The OMS-MISO survey provides a regional view of resource adequacy for the 2025/26 through 2029/30 planning years and complements other MISO planning processes, including the annual Planning Resource Auction and long-term Futures analyses.
