ERCOT has filed Planning Guide Revision Request 146 (PGRR146), “Rename Quarterly Stability Assessment and Modify the Assessment Schedule”. While not yet approved, the proposal signals a shift in how ERCOT manages its operational stability assessment process. Developers might need to begin factoring the proposed timeline changes into their interconnection planning.
It is important to note that PGRR146 remains proposed rule language. All provisions discussed below are subject to stakeholder review, committee votes, and ERCOT Board and PUCT approval before taking effect.
Why ERCOT Is Proposing the PGRR146 Changes
Since 2018, ERCOT has conducted the QSA to assess the impact of planned large generators connecting to the ERCOT System. By 2025, both the number of projects and the total capacity assessed had approximately doubled compared to 2018.
The majority of those projects are IBRs, including wind, solar, and ESRs. ESRs require evaluation under both charging and discharging conditions, multiplying the number of study scenarios per project and the associated analytical effort. The broader system impact is also visible in real-time operations. The number of Generic Transmission Constraints (GTCs) enforced to maintain grid stability has grown from 4 in 2014 to 26 in 2025.
Since February 2026, all planned Large Loads must also be included in a QSA prior to Initial Energization, and Large Loads can span multiple QSA cycles based on their Load Commissioning Plan (LCP). ERCOT's position is that moving to a four-month cycle provides the additional time needed to conduct rigorous, accurate assessments without compromising the integrity of the results.
ERCOT’s New Project Assessment Schedule
For developers, this is the most operationally significant change that will be part of PGRR146. The proposed table is planned to replace the existing quarterly structure with a three-cycle-per-year framework:
As interconnection processes tighten under the new cadence, two items carry important consequences for generators and large loads moving through the queue:
- Prerequisite Deadlines Are Hard Gates: There is no flexibility here: projects that miss the prerequisite deadline lose eligibility for Initial Synchronization (for generators) or Initial Energization (for large loads) during that assessment period. Missing the gate means waiting for the next cycle entirely, and under the new cadence, that wait is longer than it is today. For project teams, that makes early tracking of prerequisite milestones essential, not optional.
- The 45-Day Dynamic Model Submission Requirement Remains: Large generators and large loads must still submit final dynamic models at least 45 days before the QSA deadline. If that 45th day falls on a weekend or holiday, the deadline rolls to the next business day.
Build both deadlines into your project schedule now. A missed gate under the new cadence costs more time than it used to.
How EPE Can Support Your ERCOT Projects Following the PGRR146 Changes
EPE's interconnection team has deep experience supporting clients through every stage of the QSA process, from reactive power compensation studies, dynamic model development submission (PSSE, PSCAD and TSAT MQTs) to QSA prerequisite tracking and study coordination. As the assessment schedule and requirements continue to evolve, early preparation and accurate modeling will be critical to avoiding cycle delays.
EPE has supported about 60% of projects accepted through ERCOT QSA windows over the past three years. If you would like to discuss how to prepare for your upcoming QSA deadline and how EPE can support, please reach out to our team using the form below.
.png&w=3840&q=75)
.png&w=3840&q=75)
.png&w=3840&q=75)