NYISO Capacity Market: Forecasts, ICAP Insights & Merchant Curves

Last updated: April 2026. Reviewed every 6 months alongside Noreva’s merchant curve releases.

NYISO operates one of the most locationally complex capacity markets in the United States. New York’s Installed Capacity (ICAP) market is defined by severe transmission constraints, particularly into New York City (NYC) and the Lower Hudson Valley (LHV), which create persistent structural premiums for capacity that can reliably serve these constrained load pockets. For developers, lenders, investors, traders, and asset owners, understanding NYISO’s locational capacity structure is as important as understanding the broader statewide market.

Noreva provides institutional-grade NYISO capacity forecasts, including ICAP auction informedlong-term merchant curves, covering all major locational zones and seasonal dynamics. Our NYISO coverage is designed for project finance, underwriting, valuation, and commercial decision-making.

NYISO Capacity Market: Quick Summary

  • NYISO operates a locational ICAP capacity market with New York City (NYC), Lower Hudson Valley (LHV), Long Island (LI), and Rest of State (ROS) zones
  • Prices are driven by transmission constraints and demand curve design

Noreva provides:

  • 1–5 year forward market pricing
  • 25-year fundamentals merchant curves
  • region-level data (NYC, LHV, LI, ROS)

How NYISO’s Capacity Market Works

NYISO’s ICAP market differs materially from PJM’s RPM and ISO-NE’s FCM. Rather than relying on a single annual forward capacity auction, NYISO operates a layered capacity market built around seasonal capability periods, monthly procurement, spot-market residual balancing, and bilateral contracting. Each Capability Year is divided into a Summer Capability Period and a Winter Capability Period, with each period covering six months.

NYISO also distinguishes between Installed Capacity (ICAP) and Unforced Capacity (UCAP), with UCAP serving as the capacity quantity used to satisfy LSE obligations and settle capacity transactions. The ICAP-to-UCAP conversion reflects resource availability, outage performance, and, for applicable resource classes, accreditation factors. That derating and accreditation distinction is central to realistic revenue modeling because capacity revenues are ultimately earned on qualified UCAP, not nameplate ICAP alone.

NYISO conducts Capability Period Auctions prior to each capability period, allowing Unforced Capacity to be purchased and sold for the full duration of the relevant six-month season. These auctions provide a forward seasonal price reference and facilitate longer-term capacity transactions between market participants, but they are not equivalent to PJM’s centralized forward RPM construct.

NYISO also runs Monthly Auctions, through which Unforced Capacity can be purchased or sold for the upcoming obligation procurement period and, where applicable, other remaining months in the capability period. These auctions provide an intermediate procurement layer between the seasonal strip market and the final spot auction.

The ICAP Spot Market Auction is conducted immediately before each monthly obligation procurement period and is the mandatory residual clearing mechanism for LSE capacity obligations. All LSEs participate, and the auction uses the applicable ICAP Demand Curves to determine the market-clearing price for Unforced Capacity.

Capacity can also be procured bilaterally outside NYISO-administered auctions, allowing market participants to contract directly and certify capacity against LSE obligations. This bilateral layer is a core feature of NYISO’s market structure and reinforces that realized capacity value is not determined solely through one centralized auction event.

NYISO uses downward-sloping ICAP Demand Curves to translate supply-demand balance into monthly spot-market capacity prices. These curves are reset through a quadrennial Demand Curve Reset process and are anchored by reference-resource economics, including Net CONE and related assumptions. The demand curve, rather than a purely vertical procurement target, shapes how aggressively prices rise when supply tightens. Demand Curve Resets are therefore among the largest drivers of multi-year ICAP price changes and remain a focal point of Noreva’s near-term forecast scenarios.

Locational Capacity Zones

NYC is one of the most constrained capacity zones in the US. Transmission limits severely restrict imports from outside the city, which means a large share of reliability needs must be met locally. That creates a persistent premium over less constrained areas. The extreme tightness of the NYC grid and its pricing implications are explored in New York’s Power Pricing Paradox.

The Lower Hudson Valley is a constrained corridor between upstate supply and the NYC metro area. LHV prices typically sit above Rest of State but below the NYC premium, reflecting constrained import capability and its role as a transmission bottleneck.

Long Island (Zone K) is a separate locality with its own ICAP demand curve, reflecting limited transmission ties to the rest of the state. Long Island prices can diverge significantly from both NYC and Rest of State depending on local supply conditions, import capability, and offshore wind interconnection dynamics.

Rest of State represents the broader, less constrained upstate market baseline. ROS capacity typically clears below NYC and below the tighter localities because the underlying transmission and supply conditions are less restrictive.

Zone

Coverage

Constraint Level

Typical Price Relationship

New York City (NYC)

Five boroughs and ConEd load pocket

Highest

Significant premium over Rest of State

Lower Hudson Valley (LHV)

G-I locality / constrained downstate corridor

Moderate to high

Premium over ROS, below NYC

Long Island (Zone K)

Long Island locality

Distinct local constraint

Can diverge from both NYC and ROS

Rest of State (ROS)

Upstate New York baseline

Lower

System baseline

What Drives NYISO Capacity Prices?

Transmission constraints into NYC and the Lower Hudson Valley are structural and long-lived. These constraints are among the main reasons local capacity values persist at a premium. New transmission investments can materially alter those premia over time, making transmission development a core input to forward price modeling. The broader importance of transmission to NYISO capacity outcomes is examined in Transmission Matters Most in Bleak NYISO Forecasts.

New York’s long-term decarbonization strategy affects both retirement expectations for existing thermal generation and the pace of new zero-carbon entry. This creates uncertainty around the balance between reliability needs and replacement supply, especially in constrained downstate zones.

New York’s offshore wind buildout is a major factor in long-term adequacy and ICAP pricing. Offshore wind can earn ELCC-adjusted capacity credit, but those values may evolve as penetration grows and transmission integration changes. That makes timing, scale, and accreditation central to long-term forecasts.

NYISO distinguishes between two capability periods: Summer Capability Period and Winter Capability Period. Summer ICAP prices are generally stronger because of air-conditioning load and downstate peak stress, while winter prices reflect a different set of load and dispatch conditions. Noreva’s NYISO coverage separates these seasonal dynamics explicitly.

Capability Period

Months

Primary Load Driver

Typical Price Level

Summer Capability Period

May to October

Air-conditioning load and downstate peak stress

Higher

Winter Capability Period

November to April

Heating-related load and winter dispatch dynamics

Lower to moderate

Noreva’s NYISO Capacity Coverage

Noreva provides strip auction clearing price forwards for NYC, LHV, and ROS, across both summer and winter capability periods. These prices are designed to support underwriting, acquisition analysis, valuation, and trading workflows. These prices are sourced directly from brokers, so they represent where the market is currently trading NYISO capacity.

Noreva’s NYISO capacity merchant curves extend 25 years and are intended for long-dated valuation, project finance, portfolio strategy, and commercial analysis. These curves are calibrated to long-term changes in transmission, policy, offshore wind entry, and locational supply conditions. The broader dynamics of New York’s pricing environment are discussed in New York’s Power Pricing Paradox.

Noreva’s NYISO forecasts include technology-specific capacity accreditation models for all relevant resources. These adjustments are important for realistic revenue modeling and for understanding how new supply may affect future local clearing conditions.

Why Noreva for NYISO Capacity Forecasting

Noreva combines fundamentals-based modeling with trader-informed pricing inputs, a methodology no other NYISO capacity data provider offers at this depth. Learn more about Noreva and the broader capacity services we offer. Our NYISO coverage is built around five differentiators:

  • Fundamentals + transactional insights: We pair our in-house supply, demand, and policy modeling with live broker inputs and bilateral transaction data sourced through affiliated market-participant trading and origination experience across NYC, LHV, Long Island, and ROS.
  • Low / Base / High scenarios: Every NYISO forecast ships with three calibrated scenarios, enabling risk teams, lenders, and developers to stress-test assumptions on various policy environments and fundamentals inputs.
  • Custom scenario support: Clients can work with Noreva to adjust assumptions such as load growth, retirement schedules, ELCC factors, offshore wind interconnection timing, transmission constraints, and locality-specific supply inputs. These sensitivities can then be incorporated into NYISO forecast outputs across NYC, LHV, Long Island, and ROS.
  • Full data stack through Noreva Data Hub and API: Historical ICAP weekly forward marks, region-level summer and winter splits, and 25-year merchant curves, all accessible through the Noreva Data Hub or directly via API for integration into project finance models, DSCR engines, and trading systems.
  • Advisory layer: Beyond data, Noreva supports clients with asset valuation reports, pro-forma reviews, PPA and offtake structuring, origination advisory, and project benchmarking, drawing on Karbone’s direct NYISO market experience.

Use Cases: Who Relies on NYISO Capacity Forecasts

Projects targeting downstate interconnection points need to understand both contracted revenues and the incremental ICAP layer. Noreva’s zone-specific NYISO capacity forecasts support revenue modeling and project-finance assumptions.

Existing gas generation in NYC, LHV, ROS, or Long Island can derive material value from local capacity premia. Understanding the trajectory of those premia matters for hedging strategy, capex planning, and asset valuation.

NYISO capacity revenues can be a material component of lender cases for downstate assets. The rigor of capacity price forecasting is central to debt sizing, downside analysis, and valuation work for NYISO projects.

NYC, LHV, and Long Island capacity positions are among the more actively watched locational markets in the US. Noreva’s near-term price views support strip-auction analysis, bilateral pricing, and commercial strategy.

NYISO Capacity Market: Key Concepts

  • ICAP: Installed Capacity, the core NYISO capacity construct.
  • UCAP: Unforced Capacity, adjusted for outage performance.
  • NYC capacity: The most constrained and structurally premium locality in the market.
  • LHV capacity: A constrained downstate corridor with a premium over ROS.
  • Long Island capacity: A distinct locality with separate local dynamics.
  • Rest of State (ROS) capacity: The broader upstate baseline market.
  • Locational capacity: Capacity value tied to the ability to serve a constrained zone.
  • Resource adequacy: The reliability objective underpinning the ICAP market.
  • ELCC: A capacity accreditation framework relevant to variable and storage resources.
  • NYGATS: New York’s generation attribute tracking system.
  • Capacity merchant curves: Long-dated forward price curves used in valuation and underwriting.
  • Generation asset valuation: The broader valuation discipline that integrates capacity forecasts with energy revenues, costs, and policy incentives.

How NYISO Compares to Other US Capacity Markets

US Capacity Market Design Comparison

Market

Auction Format

Procurement Horizon

Commitment Period

Locational Granularity

Performance Obligation

CAISO

Bilateral (no centralized auction)

Annual + monthly + 3 to 5yr (MTR)

Annual + monthly

System / Local RA zones

RA showings

ISO-NE

Descending clock, transitioning to prompt/seasonal at FCA 19

~3 years forward currently; prompt from FCA 19

Annual currently; seasonal from FCA 19

System + CT, ME zones

Pay-for-Performance

MISO

Bilateral + seasonal PRA

Annual

Four seasons

10 Local Resource Zones

ELCC + accreditation

NYISO

Spot + strip + bilateral

Seasonal, Monthly, Monthly-Spot

Summer / Winter capability periods

NYC, LHV, LI, ROS localities

UCAP derating + ICAP demand curve

PJM

Sealed-bid (BRA) + bilateral

~3 years forward

Annual

RTO + LDAs

Capacity Performance

SPP

Bilateral

Annual

Summer + Winter

System + sub-zones

ELCC & PBA

For broader market commentary across all US capacity markets, see Noreva’s Market Views.

Frequently Asked Questions: NYISO Capacity

NYC’s transmission constraints limit the ability of external capacity to serve the city’s reliability needs. That locational scarcity creates a persistent premium for capacity that is electrically deliverable to NYC.

These are NYISO’s key locational capacity areas. NYC is the most constrained zone, LHV is a constrained corridor, Long Island is a separate locality with its own demand curve, and ROS is the broader upstate baseline market. Each can clear at a different ICAP price depending on local supply and transmission conditions.

Offshore wind can receive ELCC-adjusted capacity credit in NYISO. As offshore wind penetration grows, accreditation values and local price impacts can evolve, which makes timing and volume of entry important for long-term forecasts.

State decarbonization policy influences both retirement timing for thermal assets and the pace of new clean power entry. That interaction remains one of the core drivers of long-term NYISO forecast uncertainty.

NYISO capacity price forecasts can be accessed through specialized data providers such as Noreva. Noreva offers NYISO pricing data, including broker-reported forward market prices and long-term forecasts across all major locational zones (NYC, LHV, Long Island, and Rest of State). These datasets are available via the Noreva Data Hub and API, allowing direct integration into valuation models, underwriting workflows, and trading systems.

Yes. Noreva provides long-term NYISO capacity merchant curves extending up to 25 years. These curves model future pricing across NYC, LHV, Long Island, and Rest of State, incorporating transmission constraints, policy developments, offshore wind buildout, and generation retirements. They are designed for project finance, asset valuation, and long-term portfolio strategy.

Noreva is a data provider offering NYISO pricing, forward curves, and capacity forecasts. Its datasets include spot and strip auction prices, locational pricing across NYC, LHV, Long Island, and ROS, and long-term merchant curves used by developers, investors, lenders, and traders.

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Noreva’s NYISO capacity datasets cover NYC, LHV, Long Island, and Rest of State, with seasonal splits, locational analysis, and long-term merchant curves structured for direct use in project finance, valuation, and commercial workflows.

To learn how Noreva’s NYISO capacity forecasts can support your next transaction, underwriting process, or portfolio decision, book a demo with our team.