The Midcontinent Independent System Operator (MISO) has released its winter readiness assessment for the 2026-2027 season, projecting sufficient generating capacity to meet expected electricity demand across its region.

MISO's annual Planning Resource Auction secured approximately 134.7 gigawatts (GW) of winter capacity offers, exceeding the projected winter peak demand of approximately 113.4 GW.

Approximately 3.6 GW of new capacity additions were offered into the auction for the upcoming winter season. Natural gas resources accounted for the largest share of these additions, with additional capacity from coal, wind, solar and battery storage. Imports from neighboring systems increased by approximately 1 GW, while suspensions and retirements reduced available capacity by 2.3 GW.

"Preparing for winter starts well before temperatures begin to drop," said Tim Aliff, MISO’s executive director of market operations. "This year's assessment reflects the ongoing work of MISO and our member utilities to bring new resources online, plan for a range of operating conditions and support reliable electric service throughout the season."

Despite the projected capacity surplus, MISO identified several factors that could present operational challenges, including tighter reserve margins, steep evening ramp periods and the potential for major winter storms.

"Our region enters this winter season with sufficient capacity to meet forecasted demand, but reliability is never something we take for granted," added Aliff. "Tighter reserve margins, steep evening ramp periods and the potential for large winter storms can create challenging operating conditions. That is why MISO and our member utilities continue to focus on preparedness, coordination and operational readiness to ensure we can respond effectively when extreme weather occurs."

The National Oceanic and Atmospheric Administration (NOAA) forecasts above-normal temperatures across much of the MISO footprint this winter, while temperatures in the South Region are expected to be closer to seasonal norms. NOAA also projects above-normal precipitation in the South Region and below-normal precipitation across portions of the Great Lakes.

MISO and its member utilities are continuing seasonal assessments, winter preparedness drills and other training exercises to strengthen operational readiness. These activities are intended to improve operators' decision-making, communication and coordination during complex reliability events.