ERCOT Batch Zero — expedited large-load process
PUCT Substantive Rule §25.494 (adopted November 2024) defines the Large Load interconnection framework for ERCOT. Backdrop: >150 GW of pending Large Load Interconnection Applications (~2× total ERCOT peak of 85.5 GW). Threshold: Large Load = ≥75 MW at single POI. Batch Zero = first batch under the new rule (captures legacy backlog); 4-5 batches per calendar year thereafter. Sponsoring TDSP is the legal applicant on behalf of the end-use customer. Flow: LIA filed → Pre-screening → Impact Study → Facilities Study + Interconnection Agreement → construction → energization (~24-48 months total). 50% MW deposit required at Impact Study entry; withdrawal forfeits deposits unless force majeure. Material modification (MW/POI/load-type) triggers restudy (+6-12 mo). Hyperscale dimensions: co-location (Configuration A pure BTM, Configuration B separately metered), Emergency Response Service (ERS) load curtailment participation, compliance with IEEE 2800 / PRC-024 ride-through. FERC Order 2023 does NOT apply (ERCOT non-FERC-jurisdictional) — ERCOT runs its own queue process.
Step 1 - PUCT §25.494 response to 150+ GW Texas large-load queue
Reference notes
The PUCT adopted Substantive Rule §25.494 in November 2024 in response to a Texas large-load interconnection queue exceeding 150 GW — roughly twice ERCOT's total peak demand (85.5 GW). The rule defines the Batch Zero framework: a sequential batching process with milestone deposits, mandatory sponsoring TDSP, and clear forfeiture rules. This is the operational foundation for any AWS Texas hyperscale footprint. Use Next → to walk through the queue context, Batch Zero eligibility, application flow, deposit/forfeiture mechanics, and hyperscale-specific dimensions.
Why PUCT §25.494
- Queue scale: >150 GW pending Large Load Interconnection Applications (mid-2025)
- Context: ~2× total ERCOT peak demand (85.5 GW)
- Pre-rule problem: no batching + speculative and ready projects treated identically
- Rule adopted: November 2024
- Policy goals: prioritize ready projects, provide TDSP/ERCOT planning inputs, ensure proper cost allocation
- Sponsoring TDSP: local utility (transmission & distribution service provider) is the legal applicant on behalf of the end-use customer
Batch Zero framework
- Threshold: Large Load = forecasted ≥ 75 MW at single point of interconnection
- Includes: data centers, electrolyzers, cryptomining, industrial expansions
- Batch cadence: 4-5 batches per calendar year (Batch Zero = first batch under new rule, captures legacy backlog)
- Required filing docs: site control, MOU/lease/purchase agreement, financing evidence, technical specs (load curve, PF, voltage, ride-through)
- Co-located gen details if applicable (covered in Behind-the-meter generation reforms lesson)
- Readiness deposit: per-MW rate set by ERCOT, partly refundable
Application flow (12-18 months of studies)
- Gate 0 — Filing: sponsoring TDSP files Large Load Interconnection Application (LIA)
- Gate 1 — Pre-screening: high-level feasibility — thermal limits, voltage, coarse contingency screen
- Gate 2 — Impact Study: powerflow (multiple scenarios), dynamic stability, short-circuit, harmonics (if power-electronic load)
- Gate 3 — Facilities Study + Interconnection Agreement: final engineering, binding cost estimate
- Gate 4 — Construction (12-36 mo) → commercial energization
- Total timeline: ~24-48 months from filing through commercial energization
Milestone deposits + forfeiture
- 50 % MW deposit rule: deposit equivalent to per-MW charge applied to 50 % of requested MW at Impact Study entry
- Scale: 100 MW data center can post several $M cumulative deposits by Facilities Study gate
- Forfeiture: withdrawal forfeits deposits unless ERCOT finds factors outside applicant's control
- Material modification: MW change above threshold, POI change, or load-type change triggers restudy (+6-12 months)
- Cost categories: Direct assignment (fully borne by applicant) vs Network upgrades (allocated by methodology)
- Transmission Assignment Notice (TAN): confirms queue position + binding commitment; key document for project finance
Hyperscale-specific dimensions
- Co-location Configuration A: pure — generator on data-center campus, feeds load behind the meter
- Co-location Configuration B: separately metered — gen sells into ERCOT market, load buys from ERCOT
- Capacity payments: NONE in ERCOT (energy-only market); co-located gen earns through energy + ancillaries
- Emergency Response Service (ERS): ERCOT procures interruptible loads — 10-min or 30-min response — data centers can earn compensation
- Operational obligations: IEEE 2800 ride-through, PRC-024 V/freq ride-through, MOD model data, forecast submission, drill participation
- FERC overlap NONE: ERCOT is not FERC-jurisdictional — FERC Order 2023 does not apply; ERCOT runs its own queue process
Why it matters for the AWS Grid Code Compliance Manager role
Texas is the #1 U.S. destination for new hyperscale data centers in 2025. Every AWS Texas project navigates §25.494 from filing through energization. The compliance team must engage early with the sponsoring TDSP, manage the milestone-deposit cash flow, structure the co-location configuration choice, and design participation in ERS where it offers revenue. Mistakes in any of these compound over 24-48 months — the cost of misalignment is measured in tens of millions of dollars and delayed energization.