FERC Approves SPP's Consolidated Planning Process
Decision Marks a Major Shift in Transmission Planning and Generator Interconnection
Highlights
- The Federal Energy Regulatory Commission (FERC) has accepted Southwest Power Pool's (SPP) Consolidated Planning Process (CPP) as just and reasonable, endorsing a unified approach that integrates long-term transmission planning and generator interconnection in a single framework. FERC approved SPP's use of standardized, upfront GRID-C charges for interconnection customers, paired with continued Highway/Byway cost allocation to load, as consistent with cost causation principles.
- The CPP's 20-year and 10-year planning assessments are designed to identify and build multi-value transmission projects in advance of need, rather than reacting to individual interconnection requests.
- The move to an annual Interconnection Cluster Study with a single decision point is intended to reduce queue backlogs, limit speculative projects and improve study timelines. Though it offers greater cost certainty, the CPP requires increased financial security and earlier commitments from interconnection customers.
- Commissioners and industry observers view the CPP as a potential template for other Regional Transmission Organizations and Independent System Operators grappling with load growth, data centers, electrification and interconnection delays.
The Federal Energy Regulatory Commission (FERC or Commission) on March 13, 2026, issued an order accepting, subject to conditions, tariff revisions submitted by Southwest Power Pool Inc. (SPP) to implement a new Consolidated Planning Process (CPP) that integrates regional transmission planning and generator interconnection into a single, coordinated framework. The decision represents one of the most significant structural reforms to transmission planning and interconnection processes approved by FERC and has immediate implications for developers, transmission owners, load-serving entities and other stakeholders across the SPP footprint.
Background
SPP proposed the CPP in response to historic load growth, interconnection queue backlogs, escalating network upgrade costs and widespread project withdrawals driven by cost and timing uncertainty. Under SPP's legacy framework, regional transmission planning and generator interconnection studies operated largely in parallel. According to SPP and numerous commenters, this separation led to suboptimal transmission solutions, repeated restudies and inefficient cost allocation outcomes. FERC agreed that these structural issues posed risks to reliability and affordability and found that SPP's proposal reasonably addresses those challenges by planning transmission infrastructure holistically for both forecasted load and future generation.
Under the approved CPP framework, SPP will replace its separate transmission planning and generator interconnection processes with a recurring three-year planning cycle consisting of two integrated transmission assessments. First, SPP will conduct a 20-year transmission assessment (CPP-20) designed to proactively identify long-term, multi-value transmission solutions needed to support forecasted load growth and future generation. The CPP-20 will also establish preidentified locations on the grid with existing or planned transmission capacity and determine Generalized Rates for Interconnection Development Contribution (GRID-C), which are standardized, per-megawatt charges that reflect a generator's share of planned transmission upgrade costs.
Second, SPP will conduct annual 10-year transmission assessments (CPP-10) that integrate an Interconnection Cluster Study (ICS) with near-term regional transmission planning. The ICS replaces SPP's prior multistage interconnection study process with a single, annual cluster window and one decision point at which developers must either commit to proceed or withdraw. The results of the ICS are then incorporated directly into the CPP-10 transmission planning assessment, allowing SPP to recommend transmission projects for construction that address both interconnection and regional system needs.
A central feature of the CPP is the GRID-C cost allocation framework. Rather than assigning most network upgrade costs on a project-specific, "but for" basis, the CPP allocates a portion of the costs of planned transmission upgrades to interconnection customers through upfront, fixed GRID-C charges, with the remainder allocated to load under SPP's existing Highway/Byway methodology. FERC found that this approach reasonably applies a "beneficiary pays" cost causation principle, concluding that both load and future generation will benefit from proactively planned transmission infrastructure. The Commission emphasized that the GRID-C mechanism provides developers with cost certainty before entering the interconnection queue, while also reducing speculative projects and the need for repeated restudies.
FERC also approved SPP's revised Generator Connection Procedures, which implement the CPP through a streamlined ICS process. Key changes include a shorter annual queue window, increased upfront financial security requirements tied to GRID-C charges, a single decision point and enhanced withdrawal penalties. The Commission concluded that although these provisions deviate in some respects from the pro forma Large Generator Interconnection Procedures, they satisfy the independent entity variation standard and advance the objectives of Order No. 2023 by reducing delays, increasing transparency and improving interconnection timelines.
In approving the CPP, FERC directed SPP to submit a compliance filing within 30 days to address several tariff clarifications and drafting errors identified in the order, including provisions related to directly assigned network upgrade costs for certain sub-100 kilovolt facilities, posting timelines for GRID-C rates and technical corrections to Attachment AY.
FERC Commissioners David Rosner and Judy Chang, in separate concurring statements, expressly encouraged other Regional Transmission Organizations and Independent System Operators to explore comparable approaches, emphasizing that integrated planning is increasingly necessary to accommodate rapid load growth, data centers, electrification and new generation resources.
Takeaways
FERC's approval of SPP's CPP marks a significant evolution in how transmission planning and generator interconnection can be coordinated at a regional level. For developers, the CPP offers greater upfront cost certainty and potentially faster interconnection timelines, albeit with higher initial financial commitments. For transmission owners and load-serving entities, the framework promises more efficient, multi-value transmission development aligned with long-term system needs. More broadly, the decision signals FERC's willingness to approve innovative, nontraditional planning and cost allocation structures where they are supported by robust stakeholder processes and grounded in cost causation principles.
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