SPP GIAG 03/25/26 Meeting Updates: Modeling Requirements & EMT Study Changes

April 3, 2026

SPP GIAG 03/25/26 Meeting Updates: Modeling Requirements & EMT Study Changes

SPP-GIAG Meeting Summary 03/25/26

Author: Naira Jeelani

The SPP GIAG meeting held March 25, 2026, covered administrative updates, approvals, and technical discussions, followed by GI status updates and action tracking.

Key Focus Areas: SPP GIAG

RR758 (West Deliverability Areas) endorsement
Modelling requirements (SIR 794) and EMT study process (RR755 / SIR 774)
Updates on ITP West siting and GI policy changes (RR753)
Emphasis was placed on stakeholder feedback, process transparency, and upcoming study milestones.

Key Highlights: SPP GIAG

(1.) Deliverability Analysis – West

SPP evaluated NRIS+ West Deliverability Areas, showing a consistent increase in deliverability across scenarios.
A two-area structure (Montana and Rocky Mountain) has been proposed.
Western Transmission Owners support the proposed framework.
Next step: Targeted approval at the April MOPC meeting.

(2.) Modelling Requirements (SIR 794)

Standard Modeling: Mandates validated multi-platform models (PSS®E, TSAT, PSCAD) to meet FERC/NERC accuracy and transparency standards.
Waiver & Substitution: If standard models are unavailable, a Generating Owner (GO) may submit a PSS®E UDM with a written OEM attestation, provided they document benchmarking across all three UDM platforms (PSS®E, TSAT, and PSCAD UDMs). The waiver prevents queue delays by allowing PSS®E UDM substitution, however, it increases technical complexity and engineering effort due to mandatory tri-platform benchmarking.
Hybrid plant modelling: clarifications provided; Over100 stakeholder comments under review (deadline: April 10, 2026).

(3.) GI EMT Study Process (RR755 / SIR 774)

EMT studies are required to capture fast dynamics, fault response, and IBR behavior not represented in RMS models. The shift to EMT-level analysis reflects the increasing complexity of the modern grid. Utilizing specialized expertise ensures that inverter dynamics are accurately captured, providing a high-fidelity, de-risked path to interconnection that traditional modeling can no longer support.
Commercial framework:
- $300k study deposit (shared for clustered projects).
- Stakeholder feedback:
  - Request for clear scope of work
  - Concerns regarding study cost
Approval pending via TWG and RTWG.

(4.) ITP West – Siting

Western ITP siting maps were presented.
Includes conventional, wind, solar, and hybrid resources with feasibility classifications.
Feedback requested by April 1, 2026.

(5.) Sunset GI Priority Processing (RR753)