Modo Energy's September forecast release for MISO covers three scenarios. New High Renewables and Low Demand scenarios are now forecasted alongside the Central Case. Together they show battery energy storage system (BESS) developers and investors how the market could shift with a faster renewables buildout or with slower load growth.

Averaged across the 10 zones from 2027 to 2049, a four-hour battery in MISO earns $76k/MW-year in the Central Case, $85k/MW-year under High Renewables, and $50k/MW-year under Low Demand. MISO's TB4 spreads, the daily spread between the four most and least expensive hours, run 15% wider on average under High Renewables. Low Demand leaves TB4 spreads almost unchanged but holds the capacity price in the North (LRZ 1 to 7) 81% below Central's.

Key takeaways

• ​In the Central Case, capacity payments are the largest revenue stream for a four-hour battery, at 47% of the total. Higher capacity prices in the North give a battery there $36k/MW-year more than one in the South (LRZ 8 to 10).
• All three scenarios see TB4 spreads peak in 2041. The Central Case spread climbs from $35k/MW-year in 2029 to $54k/MW-year at that peak.
• Under High Renewables, TB4 spreads average 15% wider than Central's. Higher gas prices lift the most expensive hours of the day, while 25 GW of extra solar by 2049 increasingly holds down the cheapest.
• Low Demand's TB4 spreads track Central's closely, but the North's capacity price averages 81% below Central's. A four-hour battery earns a third less as a result, at $50k/MW-year.
• MISO's battery fleet grows to 29 GW by 2045 in the Central Case as capital costs fall. By 2049, High Renewables has 1.5 GW more and Low Demand has 8 GW less.

What the three scenarios assume

For demand, the Central Case uses the Current trajectory of MISO's Long-Term Load Forecast (LTLF), with Modo Energy's base curve for gas prices. Capital costs for new generation come from the Moderate trajectories in the National Renewable Energy Laboratory's Annual Technology Baseline (ATB), while storage alone follows the Advanced trajectory.

High Renewables holds demand at the Central Case level and puts wind and solar capital costs on the ATB Advanced trajectory. Prices for gas and coal run 10% above the Central Case. To reflect tighter turbine supply and permitting, the scenario also lowers annual gas build ceilings by 10%.