ERCOT Batch Study Workshop 5: PGRR145, Large Load Updates

Author: Basit Mushtaq

ERCOT Batch Study Workshop 5- Summary 

ERCOT Batch Study Workshop 5 marked a shift from introducing Batch Zero concepts to refining the filed framework, with emphasis on:

• ERCOT’s response to stakeholder feedback on PGRR145
• Clarifications and targeted revisions post-March 10 workshop
• Stakeholder comment walkthroughs (21 comment sets)
• Continued development of CLR and BYOG constructs

ERCOT Batch Study Process for Large Load Interconnection: Key Timeline Updates  

• ILLE milestone deadline moved to July 10, 2026 (moved from July 15)
• TSP/DSP submission deadline moved to July 24, 2026
• Target Board approval: June 1, 2026
• Target implementation: August 1, 2026

These updates improve coordination between developers and TSPs and provide processing time for TSPs.

Major PGRR145 Updates Based on Stakeholder Feedback 

A. “Safe Harbor” for Legacy LLIS Projects 

• Projects that completed legacy LLIS milestones by March 4, 2026 are:
• • Deemed valid
  • Protected from invalidation risk

• Projects between March 4 – July 10:
  • May still be valid, but subject to ERCOT review
  • ERCOT will sequentially evaluate legacy interconnection studies for treatment as base load
  • RPG-endorsed will get priority in case loads share the same date
• Addresses major developer concern around study invalidation risk.

 B. Removal of “Non-Utilized Capacity”(Previously Section 9.7.4) 

• ERCOT fully removed this provision
• Confirmed it does not apply to Batch Zero base load 

C. Dynamic Data Requirement Relaxation

• Changed standard from:
  • “consistent with study data”
    → to
  • “not expected to adversely impact results”
• This introduces: 
  • Engineering judgment flexibility
  • Reduced risk of re-triggering studies for minor model changes
    

D. MIS Posting Clarification

• Study cases will be posted on MIS Secure (not MIS Certified)
• Improves Controlled transparency for stakeholders

F. Alignment with PUCT Rulemaking

Sections 9.7.1 and 9.7.2 updated to reflect PUCT Project 58481, key elements incorporated:

• Financial security requirement changed to $50K/MW from $100k/MW
• Site control updates
• Interconnection agreement requirements
• Withdrawal and commitment provisions
•  

Batch Zero Study Framework – Reinforced, Not Redesigned 

No major structural changes, but stronger clarity and positioning:

Two-phase process confirmed:

1. Batch Zero Study  

• System-wide steady-state + stability screening
• Year-by-year “reliably served MW” allocation (2028–2032)

2. Refinement Phase  

• Based on ILLE commitments
• Produces final transmission plan to RPG

Key principle emphasized: MW allocation is conditional on reliability + upgrades, not guaranteed full request

Important Clarification for Developers: If load cannot be served in 2028–2032: will be set equal to requested load in 2033 (Year 6)

Stakeholder Comment Themes 

Stakeholder feedback during Workshop highlighted several consistent concerns across developers:

• Protection of advanced projects: 
  Projects with executed agreements, completed studies, and financial commitment should be recognized as valid and not re-screened or displaced under Batch Zero
• Timing-based eligibility concerns: 
  Heavy reliance on milestone dates (e.g., March 4 cutoff) may exclude mature projects and does not fully reflect project readiness
• Recognition of RPG-driven planning: 
  Loads already supporting RPG transmission proposals should be considered in Base Load treatment to avoid disconnect between load and planned infrastructure
• Lack of clear MW allocation methodology: 
  Stakeholders noted the absence of a defined approach for allocating capacity among competing loads
• Financial commitment and regulatory alignment: 
  Need to avoid duplicative requirements and ensure alignment with PUCT, while crediting prior financial commitments
• Execution and process clarity: 
  Requests for clearer definition of ERCOT vs TSP/DSP roles, data requirements, and study inputs

CLR and BYOG – Still Evolving Concepts 

Workshop continued advancing flexible integration pathways but did not finalize design:

• ERCOT confirmed:  
  • Separate revision requests planned (target April filing)
  • ERCOT presented conceptual Batch Zero BYOG operating configurations for Large Load interconnection:
• PUN+
  • Configuration satisfies G-1 ≥ load (loss of one generator still allows remaining units to serve the load)
  • Load is treated as firm
  • No planning or administrative limit at POI
  • No transmission upgrades from batch study since configuration is G-1 secure
• Batch Self-Limiting Facility (SLF)
  • Site operates with a fixed transmission withdrawal limit determined through batch study
  • Transmission upgrades required if identified by the batch study to meet reliability criteria

Bottom Line 

• Workshop #5 was a refinement milestone, not a redesign.
• ERCOT is locking down Batch Zero for governance approval
• Stakeholder feedback has materially shaped key provisions
• The process is now: More certain, aligned with PUCT policy but still evolving on CLR/BYOG integration

Additional Resources From ERCOT Batch Study Process for Large Load Interconnections Workshop #5

ERCOT-Large-Load-Batch-Study-Workshop-20260324_v3PGRR145 Eolic Development Partners Presentation on CommentPGRR145 Oncor Presentation on Comments_20263020

PGRR145 Vistra Presentation on Comments 20260324