The September 3 MISO IPWG meeting advanced several high-stakes topics shaping how projects enter and move through the MISO interconnection queue. Stakeholders debated modeling requirements for inverter-based resources (IBRs), updates to critical Business Practice Manual (BPM-015) attachments, generator replacement procedures, and surplus interconnection rules—all against the backdrop of FERC’s evolving interconnection directives. Below is a detailed summary of the meeting.
Key Discussion Items from MISO IPWG Meeting
DPP Study Cycle Update
Participants reviewed the status of the 2025 Definitive Planning Phase (DPP) cycles. MISO outlined application volumes, study start dates, and projected completion timelines, emphasizing the need to maintain schedule discipline despite record queue size. Developers were reminded that milestone compliance remains critical to avoid restudy risk as multiple cycles overlap.
Inverter-Based Resource (IBR) Modeling and Conformance
A focal point was proposed requirements for more rigorous dynamic modeling of solar, battery, and hybrid resources. MISO staff presented potential additions to BPM-015 appendices that would mandate benchmark tests, updated inverter control data, and formal attestation of model accuracy. Stakeholders voiced concern over implementation timing and vendor coordination but agreed that accurate IBR modeling is essential to maintain reliability as inverter-dominated projects grow across the footprint.
Attachment GGG Enhancements
Discussion turned to Attachment GGG revisions designed to clarify how interconnection customers may modify requests after initial study phases. Proposed changes include clearer thresholds for when a modification triggers a restudy, documentation standards for model updates, and tighter guardrails to preserve queue integrity. Several participants urged MISO to pair any added flexibility with firm deadlines to avoid indefinite delays.
Surplus Interconnection and BPM-015/Attachment X Updates
MISO sought feedback on draft surplus interconnection provisions intended to streamline the process for projects seeking to use unclaimed injection capacity at existing points of interconnection. Updates would clarify modeling requirements and cost allocation, particularly when surplus injections overlap with active queue positions. Developers welcomed the potential efficiency gains but cautioned that surplus rights must be carefully defined to prevent conflicts with queued projects.
Generator Replacement Process Revisions
Enhancements to the generator replacement process generated lively discussion. MISO is considering allowing limited movement of the Point of Interconnection (POI) for replacement resources within a defined electrical distance, provided no adverse system impacts are introduced. Stakeholders debated how to quantify “no harm,” with suggestions ranging from DFAX change limits to strict voltage-level boundaries. Concerns focused on preventing “queue jumping” while enabling reasonable flexibility for retiring units.
Coordination with FERC Orders and Future Compliance
Staff provided updates on ongoing filings related to FERC Order 2023 and Order 881. Several proposed BPM changes are designed to align MISO’s interconnection procedures with forthcoming federal compliance requirements. Stakeholders were encouraged to monitor Federal Energy Regulatory Commission dockets closely to anticipate tariff amendments that could follow from these discussions.
Developer Implications
Projects seeking interconnection in MISO’s territory should prepare for stricter IBR modeling standards and plan vendor engagement well in advance of DPP milestones. Surplus interconnection opportunities may open new avenues for capacity expansion, but developers must track evolving documentation and cost-allocation rules. Proposed generator replacement flexibility could preserve valuable queue positions for retiring assets, yet final guardrails will determine whether replacement projects gain a meaningful advantage. Across all topics, clear transition provisions and early data readiness remain key to avoiding costly restudies or withdrawal penalties.
Rapid changes in MISO’s interconnection rules demand proactive strategy. Our experts specializes in queue analytics, power flow modeling, and regulatory tracking to help developers navigate BPM-015 updates, IBR modeling requirements, and generator replacement opportunities. Contact ZEG to align your project pipeline with the latest MISO interconnection reforms and accelerate your path to energization.
View Meeting Materials here.
