MISO 2026/2027 Capacity Auction Preview: What Midwest Commercial Buyers Must Know Before April 28
MISO's 2026/2027 Planning Resource Auction (PRA) results are scheduled for release on April 28, 2026. After Zone 4 (Illinois/Ameren) cleared at a record $72.84/MW-day in the 2025/2026 auction—a 300%+ increase from just three years prior—analysts expect further tightening due to accelerated coal retirements, interconnection queue backlogs, and data center load growth across the Midwest. Commercial electricity buyers in Illinois, Michigan, Indiana, Wisconsin, and Minnesota should lock supply contracts before results are published, as retail suppliers will immediately reprice capacity components once clearing prices are known.
Executive Impact
- →The Capacity Cost Time Bomb: MISO capacity charges, once a negligible line item at $2-5/MW-day, now represent 8-15% of total commercial electricity costs in tight zones. A further increase could push total capacity charges above $26,000/MW for the planning year.
- →Pre-Auction Procurement Window: Retail energy suppliers currently have 2025/2026 capacity costs baked into existing quotes. Once the April 28 results are published, all forward-looking quotes will reflect the new clearing prices. Businesses with expiring contracts should execute fixed-rate agreements now to avoid repricing risk.
- →Zone Divergence: MISO's zonal structure means results vary dramatically by geography. Southern MISO (Entergy footprint in LA, MS, AR) has historically cleared at much lower prices than the capacity-constrained northern zones. Businesses with multi-site operations should evaluate load shifting to lower-cost zones.
Understanding the MISO Capacity Auction
MISO's Planning Resource Auction is the annual mechanism that sets the price for "capacity" — the guaranteed availability of generation resources to meet peak demand across its 15-state footprint. Unlike PJM's three-year forward auction, MISO runs its PRA on a prompt-year basis, meaning the April 28, 2026 results set prices for the planning year starting June 1, 2026.
For commercial electricity buyers, the capacity clearing price is not an abstract wholesale metric. It flows directly into the "capacity" line item on your supply contract— typically expressed as $/kW-month or embedded in the ¢/kWh all-in rate. When MISO capacity prices spike, every commercial customer in the footprint pays more.
Why Analysts Expect Higher Prices
1. Accelerating Retirements
Multiple coal units across the MISO footprint have retired or announced retirement timelines since the last auction. MISO's own resource adequacy assessments have flagged a growing gap between reliable capacity and peak demand projections, particularly in Zones 4 through 7 (Illinois, Michigan, Indiana, Wisconsin). The retirement of baseload coal without a 1:1 replacement by dispatchable generation (gas or storage) structurally reduces the auction's supply margin.
2. Interconnection Queue Congestion
MISO's interconnection queue — the pipeline of new generation projects waiting to connect to the grid — is massive on paper (over 200 GW of proposed projects). However, completion rates remain low due to transmission study backlogs, permitting delays, and supply chain constraints. The net result: new generation is not coming online fast enough to offset retirements, creating the scarcity conditions that drove the Zone 4 price from ~$10/MW-day to $72.84/MW-day in just three auction cycles.
3. Data Center Demand
The Midwest has emerged as a prime target for data center development, with major campuses planned or under construction in Illinois, Michigan, and Indiana. These facilities consume 50-100+ MW each and require 24/7 firm power, adding significant baseload demand to an already tightening system. MISO has acknowledged that load forecasts for the 2026/2027 planning year reflect materially higher demand projections than prior years.
Procurement Strategies for April 2026
Lock Before April 28
The single most impactful action a commercial buyer can take is to execute a fixed-rate supply contract before the auction results are published. Retail energy suppliers are currently quoting forward prices based on the existing 2025/2026 capacity costs. Once the 2026/2027 results hit, all pending quotes will be repriced to reflect the new clearing prices — which could be materially higher.
Consider Demand Response Enrollment
MISO offers demand response programs that allow commercial and industrial customers to receive capacity credits in exchange for agreeing to curtail load during system emergencies. For facilities with operational flexibility (manufacturing plants that can shift production, warehouses with thermal mass), demand response participation can offset 30-50% of capacity cost exposure.
Evaluate Zone Arbitrage
Multi-site operators should analyze which MISO zones their facilities sit in. Southern MISO zones (Entergy territory in Louisiana, Mississippi, Arkansas) have historically cleared at significantly lower capacity prices than the northern zones. Shifting incremental load growth to lower-cost zones — or negotiating supply contracts that reflect zonal price differences — can produce meaningful savings.