​The April reference price gap between upstate and NYC narrowed year-over-year. But, it widened sharply between March and April, because upstate unforced capacity (UCAP) prices fell while NYC's held steady. Upstate UCAP prices dropped from $2.64/kW-month in March to $1.82/kW-month in April (-31%), pulling upstate Reference Capacity Prices (RCPs) down by more than $5/MW-day. NYC's UCAP price barely moved, holding at $6.26/kw-month. The result: NYC's reference price stayed around $73/MW-day, while every upstate zone fell. Upstate prices were still 34-44% higher than April 2025, but their was less convergence than in March.

Key takeaways

• Upstate UCAP prices fell 31% month-over-month to $1.82/kW-month, lowering upstate RCPs by $5/MW-day. NYC's UCAP price held at $6.26, so the West-to-NYC gap widened by $5/MW-day to $37/MW-day even as upstate reference prices rose 34-44% above April 2025.
• Upstate REAP rose 22-38% year-over-year as day-ahead TB4 spreads widened across every zone. Tighter supply from sequential nuclear refueling outages raised the marginal cost in day-ahead clearing and lifted the spread between cheap and expensive hours.
• A mid-month heat wave (April 13-17) lifted real-time prices above $60/MWh and tripled regulation prices to a $34/MWh peak. April 18 then produced the year's first sustained negative-price window, hitting a -$21/MWh low.

Upstate UCAP prices fell while NYC held steady

Upstate UCAP prices cleared at $1.82/kW-month, down 31% from March. NYC barely moved. The drop reflects looser upstate capacity conditions in the shoulder season.

That upstate drop flowed into reference prices. The capacity component for upstate batteries fell from $17/MW-day in March to $12/MW-day in April. NYC's held near $41/MW-day. The upstate-NYC gap widened by $5/MW-day month-over-month as a result.

Year-over-year trends suggest a different story. Upstate UCAP prices are still 43% above April 2025's $1.27, and Capacity Accreditation Factors stepped up to 79% (from 67%) for the Winter 2025-26 period.

Combined, payment increases and increased accreditation lifted upstate RCP nearly $5/MW-day above April 2025.

Day-ahead spreads lifted REAPs across the state

Day-ahead TB4 spreads define REAP.

In April, DA spreads rose across every NYISO zone year-over-year. Long Island led at $137/MW-day, up 38%. West, which set the floor at $98/MW-day, still increased by 22%.

Supply fluctuations and planned outages drove elevated TB spreads. New York's nuclear fleet cycled through a refueling handoff this month. Nine Mile Point 2 ramped back up at the beginning of the month. Ginna then went offline for refueling on April 6 and stayed out for 2.5 weeks, pulling average nuclear output 12% below April 2025.

Gas (+570 MW) and dual fuel (+557 MW) filled the gap, raising the marginal cost of generation in day-ahead clearing and translating directly into wider spreads.

Real-time outpaced day-ahead through the heat wave and a Saturday morning oversupply

The RT premium was defined by two distinct events: a mid-month heat wave and a Saturday morning negative-price window.

Real-time spreads continued to outpace day-ahead. The NYISO reference node TB4 cleared $113/MW-day in DA and $176/MW-day in RT, holding well above April 2025's $89 and $130 respectively.

April peaked at 82°F on April 16, roughly 32°F above April 2025's daily average. Load topped 20 GW that day, pushing April 2026's peak load 5.7% above April 2025 even as average load fell 2%.

However, April 18 produced the year's first sustained negative-price window: five hours between 7am and 11am. Saturday load dipped to 12 GW that morning, colliding with strong wind (1.8 GW), the morning solar ramp, and inflexible nuclear and hydro baseload.

By contrast, day-ahead cleared positive that morning.

Regulation prices tripled during the mid-month heat wave

The heat wave drove April's biggest ancillary service price spikes, too. Regulation prices peaked at $34/MWh on April 13, more than triple the early-April baseline near $11/MWh. Spinning reserves followed: NYC 10-minute spin reached $24/MWh on April 13 and $22/MWh on April 16. The lift reflects the higher opportunity cost of holding reserves when energy prices are elevated.

In turn, April regulation prices averaged $14.24/MWh, up 28% from April 2025's $11.11.

Batteries that stack AS revenues capture value that neither RCP nor REAP reflect.

Hudson Valley nodes offered the strongest April nodal premiums

Hudson Valley led the April nodal advantage map. Shoemaker 138kV in Orange County posted the largest premium at $7.46/MW-day above the Hudson Valley zonal reference, a 17% advantage.

Genesee co-led with Hyland LFGE (+$4.47) and Allegheny Cogen (+$4.25), both in Allegany County.

The story shifted from March, when Capital and the upper Hudson corridor took the top spots.

Across NYISO, nodal premiums will likely be the most consistent way batteries outperform their reference price month after month