On October 10, 2025, ERCOT’s IBRWG meeting convened, with the agenda centered prominently on the recently adopted Operating Guide revisions under NOGRR245, as well as interpretive guidance for clause 2.9.1.1(6), and updates from the North American Electric Reliability Corporation (NERC). Here is a brief overview of the meeting’s key takeaways.
NOGRR245 Update
ERCOT representative presented a detailed update on NOGRR245, the new Nodal Operating Guide revision aimed at tightening the performance and ride-through requirements of inverter-based resources (IBRs) connected to the bulk system. Key highlights included:
- The effective date of NOGRR245 and the associated deadline of December 31, 2025 for compliance by existing IBRs or documented exemption requests.
- Clarification of the expectation that asset owners perform firmware/software upgrades, parameter updates, and—where commercially reasonable—hardware modifications to meet the ride-through curves and performance thresholds. (This echoes earlier analysis of NOGRR245 obligations.)
- A reminder that IBR owners must document any modifications made and file reports with ERCOT, and that failure to meet defined performance thresholds could trigger enforcement or remedial plans.
- Key discussion around legacy vs. new IBR fleets, highlighting that units with SGIA (Standard Generator Interconnection Agreement) dates after June 1, 2024, face more stringent requirements.
For renewable project developers, OEMs, and asset owners, this update reiterates the urgency of aligning compliance strategy with NOGRR245 timelines. At ZEG, we encourage clients to treat these updates not as administrative check-boxes but as essential reliability design elements: the IBR fleet must support the system rather than simply rely on it.
Interpretation of NOG Section 2.9.1.1(6)
The second major agenda item was an interpretive presentation on the specific clause 2.9.1.1(6) of the Operating Guide. This clause relates to the voltage ride-through (VRT) threshold for IBRs, specifically the requirement for IBRs to remain connected under a defined magnitude and duration of voltage sag/fault, unless certain documented exceptions apply.
Key takeaways included:
- The phrase “unless a shorter clearing time requirement… is determined by and documented by the Transmission Service Providers (TSP) in conjunction with the SGIA” was emphasized. This means developers must ensure coordination with their TSP regarding fault-clearing assumptions at the Point of Interconnection.
- Units seeking exemptions must clearly document the host TSP’s fault-clearing time, provide evidence of model validation and actual performance, and submit a rationale for why full compliance is not commercially reasonable.
- OEM and RE (Resource Entity) responsibility: The presenter stressed that the IBR’s model (including protection trip settings, filtering of frequency/voltage signals, and interaction with the Plant Controller) must realistically reflect field behavior. In short: you can’t demonstrate compliance on paper but show degraded performance in actual faults.
- Implication: For older IBR units, this clause translates into not just settings adjustments, but potentially retrofit of protection systems, enhanced monitoring (ROCOF, phase-angle jump detection), and more detailed commissioning test programs.
At ZEG, we see this as a critical reminder: modeling and commissioning must not be treated as “once-and-done.” For developers and asset owners, the performance gap between modeled behavior and real event response is increasingly the regulatory focus.
NERC Updates
Updates were provided on NERC standards development, in particular projects 2020-06 (Model Verification for Generators), 2023-01 (EOP-004 IBR Event Reporting), and the upcoming standard under FERC Order 901 (PRC-029) which is expected to impact bulk-system connected IBRs nationwide.
- NERC’s Level 3 Alert on IBR commissioning and performance monitoring was referenced, reminding stakeholders that beyond ERCOT requirements, there are broader reliability drivers.
- A recurring theme: many OEMs/REs still lack adequate archival of commissioning test data, event filtration logic (ROCOF, phase-angle jump), or consistent field-to-model comparisons. This gap positions IBR owners at risk when performance fails.
- For operators in ERCOT and elsewhere, alignment with upcoming national standards (IEEE 2800-2022, IEEE P2800.2) will gradually shift from “nice to have” to “must have.”
- NERC encouraged participation of OEMs, REs, TSPs in drafting teams to refine model-validation protocols, commissioning test scopes, and event reporting obligations.
Other Business and Next Steps
From a strategic perspective, the key tasks for asset owners and developers emerging from this meeting include:
- Conduct a gap analysis for your fleet against NOGRR245 (software/firmware updates, documented model-to-field comparisons, exemption requests).
- Revisit SGIA and interconnection documentation to ensure TSP fault-clearing assumptions align with the NOG Section 2.9.1.1(6) requirements.
- Enhance commissioning/monitoring protocols to ensure real-world excursions (voltage sag, phase-angle jump, ROCOF) are captured and compared to model predictions.
- Track NERC and IEEE developments for 2026-27 implementation timelines, especially for larger IBR plants with bulk-system significance.
At ZEG, we specialize in helping developers, asset owners, and OEMs navigate the evolving landscape of IBR compliance and grid-integration risk. If you’re facing deadlines under NOGRR245, need model validation support, or are seeking a compliance roadmap aligned with ERCOT and NERC standards, let’s talk. Contact ZEG to schedule a diagnostic review of your IBR fleet’s readiness. → Request a demo or contact our team to get started.
For more on NOGRR245, IBR Compliance, NOG Section 2.9.1.1(6), and Transmission Service Providers, view Meeting Materials here.
