SPP GIAG Meeting 05/20/2026 Summary
The SPP GIAG meeting held on 05/20/2026, focused on critical regulatory and tariff updates to SPP generation interconnection practices. Key discussions centered on establishing a dedicated Electromagnetic Transient (EMT) study process for High-Voltage Direct Current (HVDC) generator tie lines under Revision Request (RR) SIR784, alongside aligning and clarifying the Modification Request Impact Study (MRIS) evaluation criteria within Business Practice 7250 to determine Material Modifications.
Action Item 1: Proposed HVDC Gen Tie Line EMT Study Process (SIR784)
Unlike standard HVAC projects, all HVDC generating facility tie line projects must undergo an EMT study.
- No Exemptions: It applies regardless of screening results and covers both IBRs and non-IBRs.
- Timeline Constraint: The EMT study agreement must be signed within 30 calendar days of the Interconnection Customer’s decision point. Studies must begin at least 15 months before the Commercial Operation Date (COD), and mitigations must be live 60 days before COD.
1. Technical Study Framework
The evaluation process centers on rigorous simulation requirements to ensure grid compatibility. The study manual updates outline a highly detailed technical scope:
- AC/DC fault and dynamic analysis.
- Evaluation of converter-driven stability, grid-forming controller capabilities, active/reactive power capabilities, and emergency power control functions.
- Sub-synchronous Oscillation (SSO) screening and localized impact studies.
- EMT model verification, benchmarking, and coordination with neighboring systems where required.
2. Study Costs & Financial Requirements
| Item | Proposed Structure & Framework |
|---|---|
| Study Deposit | $400k (Updated from the previously considered $300k baseline). |
| Technical Cost Drivers | Higher deposit reflects the added engineering complexity of HVDC interconnections, including DC fault analysis, converter-driven stability studies, and advanced control interaction assessments beyond standard AC studies. |
| Cost Allocation | Increased resource estimates account for specialized modeling tools, advanced engineering studies, and associated SPP administrative and contingency efforts. |
Action Item 2: MRIS Tariff Alignment
- Objective: Assess whether proposed Interconnection Customer (IC) changes qualify as Material Modification.
- MRIS not permitted for changes involving:
- Generator/storage retirement or replacement.
- POI substation or voltage level changes.
- Technology changes not previously studied at full dispatch.
- Study requirements:
- Not required if already studied at 100% output in all model cases.
- Required if dispatch assumptions change from prior studies.
- Any facility or topology modification must still be reported to SPP.
- Evaluation: Includes steady-state, stability, and short-circuit analysis.
- Material Modification Border: Any adverse impact, non-convergence, thermal, or voltage violation is considered a Material Modification.
- Outcomes:
- If violations occur, the IC must either reduce interconnection service or submit a new request.
- If no new constraints or queue impacts are identified, the project may proceed with a GIA amendment.
Next Steps & Regulatory Track
- June 5, 2026: Deadline for stakeholders to submit formal comments and feedback regarding the proposed manual changes and agreement terms.
- Q3 2026: Ongoing refinement of study scope boundaries and cost transparency details within future GIAG sessions.
- October 2026: Target window for Markets and Operations Policy Committee (MOPC) review and final approval tracking.
Note on Secondary Agenda Items: Secondary agenda updates during the session briefly covered routine general generation interconnection status updates. There was no discussion on the second round of JTIQ.
As SPP continues refining interconnection requirements, early technical readiness and study strategy are becoming increasingly critical. ZEG helps developers, utilities, and large load customers navigate evolving ISO/RTO requirements with engineering-led interconnection support, grid modeling, and strategic due diligence. Contact ZEG to better prepare for shifting interconnection risks and study requirements.
