The Midcontinent ISO and the Organization of MISO States recently released the 2025 OMS-MISO Survey results, reinforcing near-term resource adequacy risks as demand for electricity rises across the region.
The survey projects that the MISO region could see resource sufficiency ranging from a 1.4 GW deficit to 6.4 GW surplus of Summer Accredited Capacity by the 2027/28 planning year.
In addition, the survey findings emphasize a paradigm shift in seasonal risk is emerging.
The increased penetration of solar generation within the resource mix and its operational characteristics mean that reliability risks are spreading beyond the summer season.
“The annual OMS-MISO Survey is a critical tool in informing real-world decisions that will guide our energy future. The collaboration between MISO and OMS ensures that the information shared is not just data, but another viewpoint that leads to actionable outcomes.” said Joe Sullivan, president of the Organization of MISO States and vice chair of the Minnesota Public Utilities Commission. “We see this year over year — the insights from this survey directly influence the strategies and reforms needed to address resource adequacy challenges and navigate the evolving energy landscape effectively.”
The annual survey provides a five-year resource adequacy outlook for the region and complements the MISO region’s broader reliability planning processes.
Additional new inputs and key findings from the 2025 survey include:
• Replacement and surplus queue projects will reduce the impact of retirements by utilizing existing interconnection service, contributing around 25% of new capacity additions.
• Economic growth is driving new, large spot-load additions from data centers, reshored manufacturing and industrial projects, increasing pressure on resource adequacy.
• Recent resource adequacy reforms – including a shift to a seasonal construct and the Reliability-Based Demand Curve – enhance MISO’s and utility’s ability to assess operational risks tied to extreme weather and a shifting resource mix.
• Additional views of the pending resource accreditation methodology changes are included in preparation for the transition to Direct Loss of Load accreditation in the 2028/29 planning year.
"This survey reinforces the importance of accelerating new resource additions and carefully managing retirements as demand continues to grow," said John Bear, MISO’s President and CEO. "OMS has been instrumental in the progress we’re making in our Reliability Imperative efforts. We will continue working with our stakeholders to evolve our tools and processes to support a reliable grid of the future.”
The OMS-MISO survey assesses anticipated generating capacity over a five-year planning horizon (2025/26 through 2029/30) and is a key resource in MISO’s long-term reliability planning toolkit.
This year’s results align with MISO’s Planning Resource Auction and Futures analyses, providing a comprehensive view of system risks and resource needs, MISO and OMS said.
The Organization of MISO States was formed in June of 2003 by the regulators from fourteen Midwestern states and the province of Manitoba that had member utilities in what was then named the Midwest Independent System Operator.
As MISO’s (later changed to Midcontinent Independent System Operator) membership changed, the makeup of OMS did as well.
In December 2013, OMS welcomed its five newest members from the south to achieve its current construct when the Entergy Region joined MISO.
MISO is the electric grid operator for the central United States.
