Dive Brief: The Midcontinent Independent System Operator appears to have adequate power supplies for its next planning year, which starts June 2026 — an improvement from a year ago, according to a survey discussed at a workshop the grid operator held Friday. MISO will have a potential surplus over an expected reserve margin ranging from 1.4 GW to 6.1 GW in accredited capacity for next summer, according to the latest Organization of MISO States-MISO annual survey. Last year’s survey indicated that MISO faced a 2.7 GW shortfall to a 1.1 GW surplus for this summer. “The 2025 OMS-MISO resource adequacy survey reinforces that ongoing collaboration and information sharing through this tool is driving real progress,” Joe Sullivan, OMS president and vice chair of the Minnesota Public Utilities Commission, said during the workshop. “Capacity margins have improved since last year, and positive trends continue to emerge year over year, but we must keep up that momentum and continue to accelerate it.” Dive Insight: The OMS-MISO survey comes as utilities face growing demand for electricity, mainly from data center development. The survey indicates that electricity demand in MISO will grow 2.2% a year over the next five years, up from 1.6% annual growth in the last survey. The survey report, which is based on information collected in April, offers two forecasts: one, called the historical projection, is based on a three-year average pace of bringing power supplies online; the other, called the emerging projection, is based on MISO member responses to the survey. The historical projection results in an estimate that 3.5 GW of accredited capacity will be brought online annually on average; the emerging projection indicates 6.2 GW, on average, will begin operating each year. Using the historical projection, MISO could need an additional 1.5 GW to meet its reserve margin requirement for summer