Transition Cluster Study

This page provides information about the Transition Cluster Study. The Transition Cluster Study is governed by Attachment R to BPA’s Open Access Transmission Tariff and the Transition Process Business Practice

Transition Cluster Schedule

Cluster Study Participants:

There are 167 requests being studied in the Transition Cluster Study. Here is the cost estimate for the Transition Phase 1 Cluster Study. Here is the map of requests being studied in the Transition Phase 1 Cluster Study:

The Transition Cluster Study is currently in the Phase 1 Cluster Study step of the study process. The Phase 1 Cluster Study began on April 19, 2025, and the expected completion date is January 30, 2026. BPA will provide Cluster Study updates via Tech Forum announcement.

Next Steps

After the Transition Phase 1 Cluster Study is complete, BPA will begin the 90 Calendar Day Customer Review Period. BPA will host a Cluster Study Report Meeting in the first 10 Business Days of the Customer Review Period.

Customers can request a change to their Generator Interconnection Request within 45 Calendar Days of the start of the Customer Review Period by submitting this form (link) to GI_ClusterStudies@bpa.gov

Before the end of the Customer Review Period, customers with a request being studied in the Phase 1 Cluster Study must submit the following:

  • Redemonstration Form
  • Commercial Readiness redemonstration
    • If electing to use the Commercial Readiness Deposit option, the deposit is 10% of the cost of facilities identified in the Phase 1 Cluster Study Report, less any Commercial Readiness deposit already held by BPA. Submit Commercial Readiness Deposit information to CRDepositAdmins@bpa.gov
  • Site Control redemonstration
    • Includes a Site Control Demonstration Form
  • Dynamic, short circuit, and EMT models as described in the Redemonstration Form.
  • Updated Single Line Diagram

BPA will use reasonable efforts to determine if a Phase 1 Cluster Restudy is necessary no later than 30 business days after the end of the Customer Review Period.

History

BPA determined that any requests received after November 22, 2023, would not be eligible for the transition cluster study and would need to be resubmitted for the post-transition cluster study. On November 23, 2023, BPA had 363 requests in the Large Generator Interconnection Queue. These requests were sorted into Bypass, Late Stage, and Transition Cluster groups.

Late Stage and Transition Cluster Requests were required to submit transition applications including Site Control and Commercial Readiness requirements. The transition applications were due September 28, 2024.

BPA validated transition applications until March 5, 2025. On March 5, BPA held a Cluster Scoping Meeting to discuss the requests received, the proposed grouping of the requests, and next steps for the study process. The meeting materials for the Cluster Scoping Meeting can be found here.

BPA processed study deposits and Phase 1 Cluster Study Agreements until April 19, 2025, when the Phase 1 Cluster Study began. The Phase 1 Cluster Study was scheduled to complete August 16, 2025, but a delay notice was sent on July 23, 2025, that set the new scheduled completion date to January 30, 2026.