ERCOT IBRWG 03.27.2026 Executive Summary
Author: Aabid Hussain
The March 27 ERCOT IBRWG meeting was centered on improving IBR performance and compliance through three parallel tracks:
(1) potential ERCOT incentives to accelerate adoption of Advanced Grid Support (AGS)
(2) better discipline around ride-through submissions and RIOO review readiness
(3) ongoing NERC/WECC/ESIG work to tighten standards, model validation, EMT practices, and commissioning expectations.
The overall direction is clearly toward stronger performance accountability, better evidence at the Resource level, and earlier verification of real field settings.
Key discussion topics – ERCOT IBRWG
Topic | What was presented | ZEG takeaway |
AGS incentive concept | ERCOT presented a concept NPRR for a one-time AGS incentive aimed at IBRs that are otherwise exempt from AGS requirements. The example framework assumes $1,500/MW, a $25 million program cap, application and evaluation windows in 2027, implementation by 12/31/2028, and payment adjusted by first-year availability. | ERCOT is signaling that grid-support functionality is becoming strategically important, even for resources not yet directly compelled to provide it. |
RIOO ride-through submissions | ERCOT emphasized that review delays are mainly caused by incomplete or incorrectly scoped ride-through packages. Submittals must be at the resource level, include capability curves and supporting documentation, clearly address RoCoF/PAJ settings, and be submitted only after the required approvals and test milestones are complete. | For developers and OEM teams, compliance is shifting from checkbox submission to evidence-based validation. Resource entities should package actual plant capability, not only inverter datasheet capability. |
WECC 2025 IBR event overview | WECC highlighted continued IBR disturbance risk and pointed to repeat themes from recent events: settings not maximized to equipment capability, firmware updates reverting corrected settings, and the importance of enforceable interconnection language and user-level protection settings. | The practical lesson is that settings governance matters as much as model quality. Change management around firmware, protection settings, and OEM/user-level parameters needs tighter control. |
NERC/ EMTWG/ ESIG updates | The materials covered Order 901-related standards progress, EMT modeling work items, draft white papers on plant model interfaces and equipment model validation, Category 2 GO/GOP compliance support, and DOE/ESIG efforts to harmonize implementation and study practices. | The industry is converging toward more standardized plant modeling, stronger validation criteria, and earlier cross-functional coordination among planners, OEMs, and compliance teams. |
Detailed notes by presentation
2.1 ERCOT AGS Incentive Program Concept Overview
- ERCOT stated that NOGRR 272 and PGRR 121, approved in 2025, will require certain ESRs withoriginal SGIAs on or after April 1,2026 to provide AGS through model demonstration and quality tests.
- ERCOT is considering a separate NPRR to create a one-time incentive for IBRs that are exempt from AGS requirements to adopt AGS within two years of approval.
- The example program design uses order of receipt, project MW rating, and a unit incentive of $1,500/MW, with total awards capped at $25 million and payment adjusted by a first-year availability factor.
- ERCOT indicated stakeholder feedback would be reviewed before submitting the NPRR in Q2 2026.
2.2 RIOO Ride-through Submittals and Review Process
- ERCOT identified the main causes of review delay as incomplete packages, capability shown at facility/site level instead of Resource level, missing capability curves, incomplete supporting evidence, and unclear RoCoF/PAJ settings.
- Resource entities were instructed to email [email protected] after submitting the RSCR in RIOO and to include the RSCR number, INR number, resource mnemonic, and whether the package is for Check List Part 2 or Part 3.
- For timing, ERCOT expects Part 2 packages before requesting Part 2 approval, and Part 3 packages only after PFR testing, reactive testing, and as-built model approvals are complete.
- Capability curves should overlay ERCOT requirements with actual Resource capability after considering all limiting equipment, protection systems, inverter/turbine limits, and RIOO-RS verification points.
- Supporting documentation must demonstrate Resource-level behavior, include OEM validation or calculations, and provide as-left settings for relays and controls. ERCOT also wants traceable sources for IEEE 2800-related capability data.
2.3 WECC Overview of 2025 IBR Events
- WECC reiterated that recent widespread IBR reductions during normally cleared faults remain a notable BPS reliability risk.
- The presentation linked ongoing disturbance analysis to broader industry actions under FERC Order 901 and to WECC and CAISO initiatives that push settings toward maximum equipment capability.
- WECC reported outreach to 77 facilities identified from prior disturbance work as potentially not optimized to equipment capability; by October 2024, responses had been received from 87% of those facilities.
- Specific findings included firmware/software updates that unintentionally reverted corrected settings, the value of stronger interconnection agreement language, and the need to identify and optimize user-level grid protection settings.
2.4 NERC EMTWG and NERC / Texas RE Updates
- EMTWG highlighted work to accelerate industry adoption of EMT modeling, with active items on resources repositories, standardization of plant model interfaces, model benchmarking, portability, and ride-through evaluation methods.
- A draft white paper on a uniform user interface and internal structure for IBR plant models is out for comments, with April targeted for IRPS/EMTWG consensus to request RSTC review.
- Another draft white paper on equipment model validation proposed Max AE-based tolerances for fault and non-fault event windows, signaling increasing rigor around model acceptance criteria.
- Texas RE summarized Order 901 standards progress, noted that Milestone 3 projects were approved by FERC in February 2026, and highlighted drafting activity for Milestone 4 as well as additional IBR-related standards work such as Project 2022-04 EMT Modeling and Project 2023-01 EOP-004 IBR event reporting.
- Texas RE also noted that 32 new generators had been added under the Category 2 IBR GO/GOP classification, with one more in process and an effective start date of May 15, 2026.
2.5 ESIG / DOE Industry Updates
- ESIG described DOE’s i2X FIRST forum as a venue to support practical and harmonized implementation of new and updated IBR-related standards, with meeting summaries intended to capture best practices, challenges, and remaining gaps.
- The March 16 grid-forming inverter workshop emphasized fundamentals, practical limitations, differing ISO and utility approaches, emerging standards pathways, and real-world project lessons learned.
- Looking ahead, ESIG indicated Season 3 of i2X FIRST will cover topics such as PRC-029 implementation updates, Milestone 4 projects, Project 2022-04 EMT modeling, IEEE 2800.2, and evolving GFM requirements.
- ESIG also announced i2X STITCH and technical assistance hours focused on harmonization of interconnection study methods and requirements.
