Modo Energy's September forecast release for NYISO carries three scenarios. A High Renewables and a Low Demand scenario are now available alongside the Central Case, giving battery energy storage system (BESS) owners and investors three views of the market's future.

Across NYISO's 11 zones and the full 2027 to 2049 horizon, a four-hour battery averages $120k/MW-year in the Central Case, $129k/MW-year under High Renewables and $109k/MW-year under Low Demand. Under High Renewables, NYISO's four-hour top-bottom (TB4) spread averages 13% wider than the Central Case. Low Demand narrows TB4 spreads by 5% and holds capacity prices down through the early 2030s.

Key takeaways

• NYISO's TB4 spreads double in every scenario. The Central Case spread peaks at $108k/MW-year in 2041, twice its 2027 level.
• High Renewables' TB4 spreads average 13% above Central. Pricier gas lifts the most expensive hours and, from 2035, extra solar pulls the cheapest hours below Central's.
• Low Demand's statewide capacity price is 67% lower, on average, than the Central Case through 2035. The scenario then overtakes Central on statewide capacity prices and TB4 spreads by 2044.
• Long Island and New York City are the most lucrative zones, where a four-hour battery earns $164k/MW-year and $154k/MW-year, driven by capacity payments.
• The battery fleet holds at 3.9 GW through the 2030s in every scenario. Falling capital costs then lift the fleet to 14.2 GW by 2049 in Central and High Renewables, and to 8.7 GW under Low Demand.

What the three scenarios assume

Demand in the Central Case comes from NYISO's Gold Book load forecast, and gas prices from Modo Energy's base curve. New generation takes its capital costs from the Moderate trajectories of the National Renewable Energy Laboratory's Annual Technology Baseline (ATB), except storage, which uses the Advanced trajectory.

High Renewables shares the Central Case demand forecast and moves wind and solar capital costs to the ATB Advanced trajectory. Gas and coal prices sit 10% above Central, and annual gas build ceilings are 10% lower to reflect tighter turbine supply and permitting.