The Electric Reliability Council of Texas (ERCOT) received 225 new large load interconnection requests in 2025 alone, accounting for a 270% MW demand increase since January.

By November 18, 2025, ERCOT was tracking about 226 GW of large loads seeking interconnection, up from 63 GW in December 2024.

The report ‘System Planning and Weatherization Update’ stresses that data centers dominate this wave, accounting for roughly 73% of large load requests. It also notes a shift toward extremely large single-site proposals, with many individual projects above 1 GW.

This scale and speed are creating planning challenges for ERCOT. The update highlights the need to consider how quickly large loads can connect and ramp, and notes ongoing work with the Public Utility Commission of Texas (PUC) to improve large-load forecasting and identify credible projects

Storage and Solar Dominate

On the supply side, ERCOT continues to see inverter based resources as the core of the interconnection pipeline.

There are 1,999 active generation interconnection requests totaling 432 GW. Energy storage accounts for 176 GW, and solar 158 GW, meaning the two technologies together account for about 77% of the total queue. Wind represents 46 GW, gas 48 GW, and other resources around 4 GW.

Even though renewables and storage still dominate, interest in gas is clearly growing. ERCOT notes that gas capacity in the queue rose from 26 GW in October 2024 to 48 GW by October 2025.

Recent synchronizations mirror this transition, with about 23 GW of new generation synchronized across 2024 and 2025, and a further 9.9 GW that has completed ERCOT review targeted to synchronize in the first half of 2026.

Texas Energy Fund projects move into the interconnection pipeline

State-supported dispatchable additions are now moving through ERCOT’s process.

The update says all 18 Texas Energy Fund projects, totaling more than 7 GW, have submitted Full Interconnection Study applications. ERCOT also reports that the first Texas Energy Fund (TEF) project, Pin Peaking, received Part 1 Approval to Energize in November 2025.

This marks the first TEF project to reach an ERCOT interconnection milestone, with the remaining TEF projects now moving through the Full Interconnection Study process.

Transmission Planning Up

ERCOT ties the jump in load and the scale of the generation queue to a much larger transmission workload.

The transmission project evaluations and the total number of reviewed projects in 2025 are more than double those in 2024. In spending terms, projects energized in 2025 total about $1.678 billion. ERCOT endorsed transmission projects totaling about $3.626 billion in 2025, comparable to the high levels seen in recent years.

ERCOT links the jump in large-load requests and the size of the generation queue to sharply higher transmission planning activity, with the number of project evaluations in 2025 more than doubling from 2024.

Winter Reliability Outlook

The winter risk picture has improved somewhat compared to prior winter periods. ERCOT attributes this to expected storage availability and lower outage assumptions. Alongside these operational indicators, ERCOT is supporting the Public Utility Commission’s Reliability Standard with expanded probabilistic simulations and updated modeling assumptions.

A Capacity Demand and Reserves report is planned for the third week of December 2025, including scenarios that reflect Texas Senate Bill 6’s large load curtailment and TEF assumptions.

ERCOT also plans to file the transmission operators’ maximum safe load-shedding estimate in December 2025 and to complete a trial probabilistic simulation benchmark for 2026.

Proposed modeling assumptions are scheduled for filing in January 2026, and official probabilistic simulations for the 2026 and 2029 study years are expected by mid-2026.

Weatherization Compliance

Weatherization is the other major system readiness focus in the report. ERCOT links its work to the PUC Weather Emergency Preparedness Rule and describes a growing inspection program that uses risk-based targeting. Winter 2025 to 2026 inspections began on December 2, 2025. These inspections prioritize new generation resources and critical transmission facilities. ERCOT also points to continued workshops and compliance tracking designed to reduce cold-weather performance risk.

Missing Information

A key technical and regulatory concern is NOGRR245, which governs inverter-based resource ride-through performance. ERCOT reports widespread missing information and incomplete dynamic model submissions in NOGRR245 compliance reviews.

As of December 1, 2025, none of the reviewed extension requests were complete, prompting ERCOT to issue Notices of Missing Information to 130 resources. Exemption requests face similar problems, with ERCOT lacking updated models or attestations from 72 resources.

For resources planning to comply by the end of 2025 or at synchronization or commercial operation, ERCOT says it is still missing dynamic models from 416 resources. ERCOT emphasizes that dynamic models are required to validate inverter-based ride-through performance and notes that large volumes of outstanding model submissions and attestations remain.

ERCOT plans to initiate Reliability Assessments for exemption requests in the second quarter of 2026, but the current backlog remains a significant near-term challenge.

 Rapid Transformation

ERCOT’s report describes a system under rapid transformation. Demand growth from data centers is arriving faster than anticipated in past planning cycles, while solar and storage dominate the supply pipeline and gas projects are regaining traction.

Transmission expansion is accelerating to keep pace with this growth, and winter preparedness rules are driving more intensive weatherization oversight. At the same time, reliability depends on closing the compliance gap for inverter based resources, especially through timely and complete dynamic model submissions.

The next round of ERCOT planning work, including major filings through mid-2026, will be shaped by how well the system manages large load uncertainty, interconnection timing, and ride through implementation.

A recent report has noted that the Pennsylvania-New Jersey-Maryland interconnection must deploy at least 16 GW of energy storage by 2032 and 23 GW by 2040 to ensure system reliability.

The U.S. energy storage market achieved its strongest ever quarter in the second quarter of the financial year 2025, with total installations reaching 5.6 GW/17.8 GWh.