MISO's Summer Capacity Price Falls to $424.30, but Data Center Growth Keeps the Margin Thin
The Midcontinent Independent System Operator released the results of its 2026 Planning Resource Auction on April 28, and the headline is relief rather than alarm. For the June 2026 to May 2027 planning year, summer capacity cleared at $424.30 per megawatt-day in Local Resource Zones 1 through 7, which cover parts of eleven states from Montana to Michigan. Zones 8 and 10 in Arkansas and Mississippi cleared at $384.10, and Zone 9, covering most of Louisiana and southeast Texas, at $412.10.
A year earlier, the summer price in the northern and central zones was $666.50. Prices in the other seasons fell much further: $33.92 for fall, $35.97 for winter and $7.61 for spring. Summer cleared with a reserve margin 3.5 percentage points above the 7.9% planning reserve margin target. The reliability-based demand curve, now in its second year, shapes the outcome as well. Summer is still tight, and MISO said so: its release describes summer prices as reflecting a tighter balance between supply and demand.
The forecast notes something that tells you where that load shows up first: Expedited Project Review requests, the process MISO uses to evaluate transmission needs too urgent for the regular planning cycle, rose from one in the 2020 transmission expansion plan cycle to 15 in the 2024 cycle, driven by large load additions. NERC's 2025 Long-Term Reliability Assessment reported MISO's forecast peak total internal demand reaching 127 GW in summer 2026, up more than 2.6 GW from the projection for the same year in the 2024 assessment, and growing to 143.7 GW by 2035.
The other half of the story is MISO's effort to bring new generation online quickly. NERC's sensitivity analysis of the expedited process found MISO projecting more than 50 GW of accredited capacity additions by summer 2029, about half of it from expedited projects. The auction price matters less in MISO than in PJM because most load-serving entities in MISO self-supply or contract for capacity before the auction.