SPP Capacity Market: Forecasts, PBA Insights & Merchant Curves

Last updated: April 2026. Reviewed bi-annually alongside Noreva’s merchant curve releases.

Southwest Power Pool (SPP) is one of the fastest-evolving capacity markets in North America. Spanning a large central-US footprint, SPP manages a grid increasingly shaped by high wind penetration, changing accreditation rules, tighter winter reliability requirements, and a market design that continues to mature. For developers, lenders, investors, traders, and asset owners with exposure to SPP, understanding capacity pricing and accreditation is essential for project finance, valuation, and commercial decision-making.

Noreva provides institutional-grade SPP capacity forecasts, including near-term price views and long-term merchant curves, with full seasonal coverage and explicit treatment of Performance-Based Accreditation (PBA) and deliverability distinctions. In SPP, capacity value is increasingly determined by performance, seasonality, and transmission deliverability.

How SPP’s Capacity Market Works

SPP’s capacity market operates through a combination of bilateral transactions, capacity showings, and evolving resource-adequacy requirements rather than a single centralized multi-year forward auction like PJM’s BRA. The market distinguishes between several capacity product types, each reflecting a different aspect of resource adequacy.

Summer deliverable capacity is capacity that can be demonstrably delivered during summer peak conditions, typically when air-conditioning demand is highest across the SPP footprint. Summer pricing is shaped by heat-driven peak load, transmission congestion, and the availability of resources that can perform during high-stress hours.

Winter deliverable capacity covers delivery during winter peak conditions and has become significantly more important since Winter Storm Uri exposed major cold-weather reliability vulnerabilities across the region. Winter pricing and accreditation are now central to SPP capacity analysis. The broader lessons from winter storm dynamics are explored in The Shape of the Storm: Lessons from Fern.

Firm capacity refers to accredited capacity paired with firm transmission service to the load-serving entity’s load pocket. It is the premium product, because it combines capacity value with specific deliverability to load.

Product

Season

Key Requirement

Market Role

Summer Deliverable Capacity

Summer

Demonstrable delivery during summer peak

Seasonal reliability product

Winter Deliverable Capacity

Winter

Demonstrable delivery during winter peak

Increasingly critical post-Uri

Firm Capacity

Year-round / load-pocket specific

Accredited capacity plus firm transmission

Premium deliverability product

SPP’s market structure is less mature than PJM’s or ISO-NE’s, but it is increasingly performance-oriented as accreditation and reserve-margin requirements evolve.

Performance-Based Accreditation (PBA) and ELCC: SPP’s Accreditation Reform

One of the most consequential developments in SPP’s capacity framework is the transition to Performance-Based Accreditation (PBA) and the use of ELCC-style methodology for variable and storage resources. This changes how capacity is valued:

  • From nameplate to performance: Capacity value is no longer determined mainly by installed MW. Instead, resources are assessed on how they perform during peak stress events.
  • Separate seasonal values: Accreditation can differ between summer and winter, reflecting different reliability conditions.
  • Technology differentiation: Dispatchable gas, well-performing storage, and reliable resources tend to earn stronger accreditation than resources that underperform during peak stress hours.

This performance-based shift is central to Noreva’s SPP capacity forecasting. Accreditation reform changes the revenue outlook for every resource type in the market. The broader valuation implications of shifting ELCC scores are examined in The ELCC Crunch: How Shifting Capacity Values Are Redefining Asset Valuation.

SPP PBA / ELCC: Impact by Technology Type

Technology

Summer Accreditation

Winter Accreditation

Broad Outcome

Dispatchable gas

High when available on demand

High if winterized

Strong accredited capacity value

Wind

Variable

Variable

Depends on stress-hour performance

Solar

Moderate

Lower

Seasonal asymmetry

Battery storage

High when properly sized and dispatched

High if operationally reliable in cold conditions

Strong capacity candidate

Nuclear

High

High

Consistent accredited contribution

July 2025: FERC Approves SPP’s PBA, ELCC, and ERAS Reforms

Two July 2025 FERC orders materially changed SPP’s resource-adequacy framework:

  • July 18, 2025, PBA and ELCC approval: FERC approved SPP’s Performance-Based Accreditation methodology for thermal resources and Effective Load Carrying Capability treatment for variable and storage resources (Dockets ER24-1317 and ER24-2953). This formalized accreditation based on actual contribution to reliability and seasonal performance.
  • July 21, 2025, ERAS approval: FERC also approved SPP’s Expedited Resource Adequacy Study (ERAS), a fast-track pathway intended to accelerate new generation needed to address capacity shortfalls through 2030.

Together, these reforms tighten accreditation standards while also creating a faster path for certain new supply. For market participants, that means forward capacity value increasingly depends on both how a resource accredits and how quickly new dispatchable supply can enter the market. Noreva’s SPP forecasting framework is designed to reflect that post-July-2025 market structure.

What Drives SPP Capacity Prices?

SPP is among the markets in the US with the greatest share of wind in its supply stack. That creates a structural tension: wind provides abundant low-cost energy, but its capacity contribution can vary materially during system stress hours. As wind penetration rises, the marginal capacity value of new wind can decline, which increases the relative value of dispatchable and highly deliverable resources. The ongoing tension between wind energy surplus and dispatchable capacity scarcity is analyzed in Dispatchable Dominance in SPP and MISO.

Winter Storm Uri fundamentally changed how SPP participants think about reliability. After Uri, winterization and winter deliverability became far more important in pricing and adequacy planning. Uri was the event that reset the market’s view of winter capacity value.

Higher PRM requirements increase demand for accredited capacity, especially for winter-deliverable products where supply is more constrained. Reserve margins are now a central market driver, with increasing divergence between summer and winter requirements.

In February 2025, SPP governance approved Planning Reserve Margins of 17% for the 2029 Summer Season and 38% for the 2029 to 2030 Winter Season, a major step up from the historical 15% reference point and a structural driver of higher forward capacity prices, especially in winter. This is one of the key current inputs to Noreva’s SPP forward views.

SPP’s footprint is also exposed to growing industrial load, data-center development, and broader electrification. That demand growth tightens reserve margins from the demand side and increases the value of accredited and deliverable capacity. Whether gas generation can fill that gap is examined in Can Gas Save SPP?.

New gas capacity, especially resources that are winterized and operationally flexible, remains one of the clearest near-term candidates to fill SPP’s dispatchable-capacity gap. Gas buildout is a central scenario variable in Noreva’s SPP merchant-curve work.

Noreva’s SPP Capacity Coverage

Noreva provides forward-looking SPP capacity price forecasts covering summer deliverable capacity, winter deliverable capacity, and broader accredited-capacity value. These outputs are calibrated for project finance, reflecting retirement assumptions, new entry, accreditation methodology, and PRM evolution. The underlying methodology is detailed on our How It Works page.

Noreva’s SPP capacity merchant curves extend 25 years and are intended for long-dated valuation, financing, and strategic planning, with long-term scenario divergence a core part of the offering.

Noreva provides separate price series for summer deliverable capacity and winter deliverable capacity, reflecting the fact that reliability conditions and resource performance differ materially by season.

Noreva’s SPP datasets incorporate PBA-adjusted capacity credit rates by technology and season. For wind, solar, storage, and dispatchable thermal resources, those adjustments can materially alter expected capacity revenues and are therefore critical for underwriting and valuation.

In Noreva’s SPP framework, firm capacity is the premium product because it combines accredited capacity with firm transmission to the load-serving entity’s load pocket. Deliverable capacity is the broader system-wide accredited product, the baseline or “paper capacity” layer when not paired with firm transmission rights. Noreva’s SPP coverage distinguishes these products explicitly, consistent with the broader concept of locational capacity value.

Why Noreva for SPP Capacity Forecasting

Noreva combines fundamentals-based modeling with trader-informed pricing inputs, a methodology no other SPP capacity data provider offers at this depth. Learn more about Noreva and the broader capacity services we offer. Our SPP 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 our sister company Karbone, which has 15+ years of capacity market trading and origination experience in SPP. Most data providers rely on fundamentals alone; Noreva ties SPP forecasts to where firm capacity, deliverable capacity, and bilateral positions are actually transacting across summer and winter products.
  • Low / Base / High scenarios: Every SPP forecast ships with three calibrated scenarios, enabling risk teams, lenders, and developers to stress-test assumptions on wind penetration, PBA accreditation outcomes, gas buildout pace, ERAS-pathway entry timing, and the 17% / 38% 2029 PRM trajectory without re-running the model.
  • Customizable scenario workbench: Clients can adjust load growth, retirement schedules, technology-specific PBA and ELCC factors, gas prices, winterization assumptions, and seasonal accreditation inputs, then re-run SPP forecasts on demand across summer, winter, firm, and deliverable products.
  • Full data stack through Noreva Data Hub and API: Historical SPP forwards, summer and winter splits, firm-versus-deliverable spreads, 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 portfolio risk systems.
  • Advisory layer: Beyond data, Noreva supports clients with asset valuation reports, pro-forma reviews, PPA structuring, origination advisory, retirement and repowering analysis, and project benchmarking, drawing on Karbone’s direct SPP market experience.

Use Cases: Who Relies on SPP Capacity Forecasts

SPP’s wind-heavy footprint attracts large volumes of renewable development, but PBA reform has changed the way capacity revenues should be modeled. Noreva’s accreditation-aware SPP forecasts help developers understand how site-specific or technology-specific performance can affect capacity value.

Winterized and dispatchable gas resources can benefit materially from elevated firm-capacity value in SPP. Noreva’s merchant curves support long-term revenue modeling for these projects.

SPP project finance requires capacity assumptions that account for seasonal pricing, accreditation haircuts, and regulatory change. The rigor of capacity price forecasting is central to lender cases and credit review, and Noreva’s scenario-based forecasts are structured for that use.

Performance obligations, accreditation risk, and winter stress conditions create downside exposure for operators. Noreva’s scenario analysis supports stress testing around these risk factors.

SPP Capacity Market: Key Concepts

  • Summer deliverable capacity: Capacity committed to delivery during summer peak conditions.
  • Winter deliverable capacity: Capacity committed to delivery during winter peak conditions.
  • SPP firm capacity: Accredited capacity paired with firm transmission service to the relevant load pocket.
  • Deliverable capacity: Accredited capacity deliverable to the broader SPP balancing-area footprint.
  • PBA: Performance-Based Accreditation, central to SPP’s current resource-adequacy framework.
  • ELCC: Accreditation approach relevant to variable and storage resources.
  • Nameplate capacity: The rated installed capacity of a resource, which under PBA is no longer the primary determinant of capacity credit.
  • Planning Reserve Margin (PRM): Reserve buffer requirement used to support system reliability.
  • Resource adequacy: The underlying reliability objective of the market.
  • Capacity merchant curves: Long-dated forward price series used in underwriting and valuation.
  • Generation asset valuation: The broader valuation discipline that integrates capacity forecasts with energy revenues, costs, and policy incentives.

How SPP 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: SPP Capacity

PBA is SPP’s reformed accreditation methodology, under which resources receive capacity credit based on demonstrated performance during system stress periods rather than mainly on nameplate capacity. Under this framework, resource performance during key reliability hours matters directly for capacity value. FERC approved SPP’s PBA methodology on July 18, 2025, making it the operative accreditation framework going forward.

Uri exposed major weaknesses in winter reliability across SPP, particularly for resources that were not adequately winterized or could not reliably perform during extreme cold. Since then, winter capacity and winter deliverability have taken on much greater value in market analysis and resource planning.

Wind provides substantial energy but not always equivalent accredited capacity during stress periods. As wind penetration rises, the marginal adequacy value of new wind will decline, which raises the relative value of dispatchable and highly deliverable resources.

No. SPP does not currently operate a single centralized multi-year forward capacity auction equivalent to PJM’s BRA. Instead, the market relies on bilateral structures, showings, and evolving adequacy requirements.

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Noreva’s SPP capacity datasets cover summer and winter deliverable capacity, firm-capacity distinctions, PBA-aware accreditation treatment, and long-term merchant curves structured for direct use in project finance, valuation, and commercial strategy.

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