MISO IPWG Meeting Summary 06/09/2026
1. Interconnection Process Background
MISO’s Interconnection Process Working Group (IPWG) is the stakeholder forum used to discuss generator interconnection process improvements, tariff changes, study schedules, affected-system coordination, and digital tools supporting the interconnection queue. The June 9, 2026 IPWG meeting focused on Attachment GGG improvements for Merchant HVDC Transmission Connection Procedures, the Definitive Planning Phase (DPP) study schedule, FERC status updates, Generator Interconnection Portal enhancements, and liaison updates.
The purpose of IPWG is to provide subject-matter input to MISO on ways to reduce study time and increase certainty in the interconnection process. This matters because MISO continues to manage a large queue, evolving tariff requirements under FERC Order 2023, expedited resource study pathways, and increasing demand for better transparency and automation.
The meeting reflected MISO’s broader shift toward process standardization. Several discussion items were not about changing technical study principles, but about clarifying pathways, improving documentation, reducing ambiguity, and helping customers understand how projects move through MISO’s interconnection process.
2. June 2026 IPWG Meeting Process
The June 9 IPWG agenda included administrative items, a liaison report, posted FERC and DPP updates, Attachment GGG improvements, a Generator Interconnection Portal product update, new business, and action items. The next IPWG meeting is scheduled for July 21, 2026.
The most substantive topic was Attachment GGG Improvements under PAC-2024-6. Attachment GGG governs Merchant HVDC Transmission Connection Procedures. MISO presented additional Tariff and Business Practice Manual changes to improve the existing Merchant HVDC interconnection process and respond to stakeholder feedback from the April 28 IPWG meeting.
Stakeholders generally supported the proposed clarifications, especially around the Module B pathway and the distinction between Necessary Upgrades and Network Upgrades. However, they requested more clarity on cost recovery pathways and the scope of upgrades identified in Attachment GGG connection studies.
2.1 Core Characteristics of Attachment GGG Improvements
The Attachment GGG discussion focused on making the Merchant HVDC process easier to understand and administer.
First, MISO clarified the difference between Necessary Upgrades and Network Upgrades. The existing definitions remain unchanged, but MISO proposed additional language to reduce confusion around which upgrades are identified through Attachment GGG connection studies and how those upgrades should be treated.
Second, MISO clarified that Merchant HVDC customers have two delivery pathways. A customer can pursue MHVDC Connection Service with Attachment X Injection Rights and convert those rights to External Network Resource Interconnection Service within three years. Separately, a customer can pursue MHVDC Connection Service with Module B Transmission Service.
Third, injection into MISO can be achieved through Module B without obtaining Attachment GGG Injection Rights. Attachment GGG Injection Rights translate to Attachment X External NRIS, while Module B is a separate transmission service pathway.
Fourth, Network Upgrades identified through the Transmission Service process are treated as Transmission Delivery Service Projects. Costs are assigned and recovered under Attachment N. A Transmission Owner may directly assign costs to the Transmission Customer and obtain a return on equity over time, unless those costs are rolled into zonal rates under Attachment O.
2.2 Key Objectives of the Proposed Changes
The main objective is to reduce uncertainty for Merchant HVDC projects. MISO is not creating a completely new process; it is clarifying how existing pathways work and how customers should understand the relationship between connection service, injection rights, transmission service, and upgrade cost responsibility.
Another objective is to separate the Attachment X and Module B paths more clearly. MISO removed earlier redlines that could have implied the Injection Rights pathway and Module B pathway were tied together. The June redlines clarify that these are separate and independent options.
MISO is also making minor updates to the Multi-Party Facility Construction Agreement and clarifying that injection and withdrawal rights are granted through other tariff processes, not directly through Attachment GGG connection service.
2.3 Relationship to FERC and Queue Reform
The FERC Status Report showed that several interconnection-related proceedings remain active. Key items include self-funding proceedings, the pending Multi-Party Facility Services Agreement filing, Attachment GGG self-funding matters, a DFAX complaint, Order 2023 compliance, the MISO-SPP Joint Targeted Interconnection Queue framework, queue cap litigation, ERAS tariff proceedings, and replacement process improvements.
Order 2023 remains a major backdrop. MISO submitted further compliance on May 18, 2026, following FERC’s March 19, 2026 compliance order. This means interconnection reform is still active at the federal level and continues to shape MISO’s tariff and process updates.
The Queue Cap filing was accepted by FERC, but appeal activity continues. MISO’s Queue Cap Tracker has been updated with DPP-2026 data, and the East/ITC regional cap has been met. This is important because regional caps can affect whether and how new projects enter a study cycle.
2.4 DPP Study Schedule and Application Fee
For the DPP 2026 cycle, the application deadline is September 10, 2026, and the study cycle kickoff is December 9, 2026. Initial draft model reviews are planned for mid-December 2026.
MISO also noted an updated D1 application fee of $7,600. Projects currently included in the DPP 2026 cycle will need to true-up the D1 fee under GIP Section 3.6, and MISO will send deficiency notices.
The DPP schedule update remains important because many earlier cycles continue to show delays, including restudy, model, mitigation, or MISO-related delays. For developers, the schedule is a practical indicator of study progress, GIA timing, and queue risk.
2.5 Generator Interconnection Portal Update
MISO provided a product update on the Generation Interconnection Application Automation portal. The portal launched fully in November 2025. Additional work over winter 2025-2026 supported JTIQ, inverter-based resource documentation, and application review automation. A dedicated product development team was established on March 1, 2026.
Recent portal updates corrected validations for surplus and replacement applications, added IBR document uploads, updated decimal precision, expanded POI voltage-level options, restricted PSS/e files to .raw, and updated the POI list.
Future releases are tentatively scheduled for July 18, September 15, and November 10, 2026. Planned enhancements include clearer layouts, improved descriptors, project name and number in portal views, refined validations, and continued cleanup of migrated GridUnity data.
Known issues include file size limits, lack of sorting and filtering, difficult contact-role management, accessibility limitations, unclear user-type options, limited contextual guidance, and redundant document generation or DocuSign steps.
2.6 What is ERAS and Queue Cap Tracking?
The liaison report included an Expedited Resource Addition Study update and Queue Cap Tracker update. ERAS is intended to provide a faster study path for certain resource additions. The Queue Cap Tracker helps stakeholders understand when regional caps have been reached for a DPP cycle.
For developers, these updates affect both entry pathways and queue visibility. ERAS may provide an alternate route for eligible projects, while queue caps can limit study-cycle participation in constrained regions.
2.7 What Next?
MISO plans to proceed to the Planning Advisory Committee with the Attachment GGG changes. Two FERC filings are targeted. The first filing, expected within the next 30 days, would address limited operations, study-scope clarification based on the application, and confirmation that injection and withdrawal rights are granted elsewhere. The second filing, targeted for Q3-Q4 2026 pending PAC response, would address the updated application form, material modification rules, Module B clarification, and Necessary versus Network Upgrade language.
MISO also announced its AI Summarization Pilot Program for stakeholder meetings. The pilot is intended to improve accessibility and transparency, but MISO noted that summaries should be verified against original materials.
3. Challenges with the Current Interconnection Process
Several challenges remain.
First, Attachment GGG still involves multiple overlapping concepts: connection service, injection rights, External NRIS, Module B transmission service, Necessary Upgrades, and Network Upgrades. MISO’s clarifications help, but customers will still need to choose the correct pathway early.
Second, cost recovery remains sensitive. Whether an upgrade is treated as a Necessary Upgrade, Network Upgrade, or Transmission Delivery Service Project can affect who pays, how costs are recovered, and whether costs are directly assigned or rolled into rates.
Third, the queue remains complex. DPP delays, regional caps, ERAS eligibility, and Order 2023 compliance all affect project timing and certainty.
Fourth, portal automation is improving, but user experience issues remain. Better validation, clearer guidance, and cleaner data will be important for reducing application errors and deficiency cycles.
Overall, the June 9 IPWG meeting shows MISO continuing to refine its interconnection process through targeted tariff clarifications, schedule transparency, digital tool improvements, and stakeholder feedback. These changes may not eliminate queue risk, but they should improve clarity for developers evaluating Merchant HVDC projects, DPP participation, ERAS eligibility, and application-submission requirements.
If you are developing generation, storage, or Merchant HVDC projects in MISO, ZEG can help evaluate interconnection pathways, study-cycle risks, upgrade exposure, and tariff implications before they affect project economics or schedule certainty. Contact our team to get started.
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