Texas Interconnection Process: Studies, Agreement, and Timeline

Connecting a new generator to the Texas grid runs through the ERCOT interconnection process: a developer files a Generation Interconnection or Change Request with the Electric Reliability Council of Texas, passes a sequence of engineering studies, signs a Standard Generation Interconnection Agreement with the local transmission provider, and then builds, commissions, and energizes the plant under ERCOT’s supervision. ERCOT manages about 90 percent of the state’s electrical load for more than 26 million customers,¹ and because its transmission lines stay inside state borders, the process is governed by the Public Utility Commission of Texas (PUCT) rather than the Federal Energy Regulatory Commission. If your project sits in the El Paso area, on the Western Interconnection, or in parts of the Panhandle and northeast Texas served by the Southwest Power Pool, none of what follows applies to you; those developers work with different grid operators under federal jurisdiction.

Filing the Interconnection Request

The application that starts everything is the Generation Interconnection or Change Request, or GINR. Developers submit it through ERCOT’s online Resource Integration and Ongoing Operations portal, known as RIOO-IS.² Whether a project qualifies for the GINR track depends on the criteria in Section 5.1.1 of ERCOT’s Planning Guide, which screens for factors like resource size and type.

Along with the GINR, you file Resource Asset Registration Forms (RARFs) that describe the physical characteristics of the proposed equipment. These feed ERCOT’s network model, the same model dispatchers use in real time. Expect to provide data on generator reactive power capabilities, inverter specifications for solar or battery projects, and transformer characteristics, so engineers can model how the plant will behave during normal operations and grid disturbances.

Site Control

Studies do not begin until you prove legal control over the project site. ERCOT’s Planning Guide accepts a deed, a lease, an option agreement, or a signed letter from the landowner confirming your right to build and operate on the property.³ Without site control documentation, the application stalls before any engineering work starts.

Application Fees

ERCOT charges $3,000 to process the Full Interconnection Study application for a new generator and $2,700 for a modification to an existing one.⁴ That fee covers the study itself. It does not cover the financial security the Transmission Service Provider (TSP) will later require to fund construction of the physical interconnection facilities, which is negotiated inside the interconnection agreement and can run into the millions.

The Study Sequence

Once your paperwork clears, ERCOT and the TSP run engineering assessments to determine how the new resource will affect the grid. The process starts with a Security Screening Study, a steady-state analysis that uses power-flow and transfer simulations tied to your proposed commercial operation date and point of interconnection. It flags obvious constraints like thermal overloads or voltage violations under normal and contingency conditions.

If the screening surfaces problems, or the project is large enough to warrant deeper analysis, it moves to the Full Interconnection Study (FIS). This is the serious engineering: power-flow, stability, and short-circuit analyses simulating how the plant interacts with existing transmission lines and nearby generators during faults and disturbances. The FIS decides whether the grid can absorb the resource without hurting reliability, and identifies which transmission upgrades, if any, are needed to accommodate it.

Larger projects then face the Quarterly Stability Assessment (QSA), which batches multiple projects together and evaluates their combined effect on grid stability. Each QSA has an inclusion deadline that falls well before the requested energization quarter, so timing your submission to hit the right cycle matters.⁵

Who Pays for the Connection

Cost allocation is one of the most consequential parts of the process, and the rules changed for agreements signed after December 31, 2025. Under PUCT Rule 25.195, the TSP pays for transmission system upgrades, meaning modifications to the broader network beyond what is needed to physically connect your generator. Building a new substation, or modifying an existing one, to create the actual connection point is not a transmission system upgrade; that cost is yours.⁶

The TSP absorbs interconnection facility costs up to a set allowance. Starting January 1, 2026, that allowance is $14 million for generators interconnecting at 138 kV or below, and $20 million for those connecting at higher voltages. Anything above the allowance is billed to the developer, and the TSP can collect those excess costs as a contribution in aid of construction before work begins.⁶ Which allowance applies to your project locks in on the date you issue the notice to proceed to the TSP.

Signing the Standard Generation Interconnection Agreement

The Standard Generation Interconnection Agreement (SGIA) turns the engineering work into a binding contract. It follows templates set by PUCT Rules 25.195 and 25.198 and spells out both sides’ responsibilities for designing, procuring, and building the physical connection.⁷ The TSP controls the composition and quality of the Transmission Interconnection Facilities (TIF). You can decide whether the TSP does all the construction or whether you take on portions of it.

Exhibit B fixes a Scheduled Commercial Operation Date and a series of milestone dates. Missing key milestones triggers day-for-day extensions of the whole schedule. Fail to secure land rights for the TIF site by 11 months before the in-service date, or fail to provide an all-weather access road by 9 months out, and the schedule slides accordingly.⁸ The SGIA is also what lenders and investors rely on when committing financing, because it fixes your place in the queue.

Walking Away, Default, and Termination

Leaving a project after the SGIA is signed has a price. If you terminate, you owe the TSP all costs incurred or committed as of the termination date that fall to you under the contract, and the TSP can keep your deposit or security to cover what it has already spent on planning, design, licensing, equipment, and construction.⁷

The TSP has its own exit. If the generator has not reached commercial operation within one year after the scheduled date, the TSP can terminate and retain the financial security to cover its sunk costs.⁸ Either party can also declare a default for failure to perform any obligation. The defaulting party has 30 days to begin curing and 90 days to finish. If the cure window closes without resolution, the non-defaulting party can terminate and pursue all amounts owed plus damages available at law or equity.

Commissioning and Going Live

With construction complete, the project enters commissioning. You submit a commissioning plan and an energization request, and ERCOT must approve the request before any high-voltage equipment connects to the grid.⁹ After energization, you request Initial Synchronization, the point at which the generator first produces electricity onto the grid. Engineers watch the unit respond to grid signals and hold the required frequency under real load.

Telemetry and Monitoring

Before commercial operation, the plant must feed real-time data to ERCOT. Your Qualified Scheduling Entity (QSE) provides telemetry through an Inter-Control Center Communications Protocol interface over ERCOT’s private Wide Area Network. That means signing a WAN agreement and providing physical facilities at the generator site, including rack space, dual uninterruptible power supply circuits, and security systems compliant with NERC Critical Infrastructure Protection standards.¹⁰

You also install disturbance monitoring equipment: fault recorders, sequence-of-events recorders, and phasor measurement units. Conventional generators must synchronize time within 2 milliseconds of Coordinated Universal Time using a GPS-based clock. Inverter-based resources like solar and battery projects have a tighter standard, within 100 microseconds.¹⁰ If telemetry becomes unavailable or unreliable, the QSE must notify ERCOT as soon as practicable and, if the issue is not fixed within two business days, provide an estimated resolution time.

How Long It Takes

From the GINR application through study completion, plan on 18 to 30 months for large generators of 10 MW or more. Smaller projects under 10 MW typically move in 8 to 12 months. These figures cover the regulatory and engineering phases only. They do not include construction or equipment supply delays, which can add significant time depending on market conditions for transformers and other long-lead items.¹¹

Construction after studies varies widely. A straightforward solar project on flat land can build out in under a year. A complex thermal plant with major transmission upgrades takes several. The SGIA milestone structure sets hard deadlines, and missing them shifts the schedule or, at worst, triggers termination rights.

The Queue You’re Joining

Anyone entering the process today should look at what’s already in line. As of February 2026, ERCOT was tracking 2,008 active generation interconnection requests totaling roughly 454 GW. On the demand side, roughly 410 GW of large loads were seeking interconnection, about 87 percent of them data centers.¹² Those figures far exceed ERCOT’s installed capacity, and study timelines, engineering resources, and equipment availability are all under strain.

ERCOT and the PUCT are reforming the process to relieve congestion. A stakeholder process is underway to move large load interconnections to a batch study model, clustering requests filed within roughly a six-month window and studying them together, with capacity allocated out of each batch reserved to reduce restudies. A new Large Load Forecasting Rule took effect March 1, 2026, setting alternative criteria for including loads in planning assessments.¹² A proposed rule on Large Load Interconnection Standards published for comment in March 2026 would require financial security of $50,000 per MW with only 20 percent refundable, a deposit sized to clear speculative projects from the queue. Track these proceedings before filing; the financial and procedural requirements are moving.

1
Texas Comptroller of Public Accounts. ERCOT Snapshot – Electric Reliability Council of Texas
2
Electric Reliability Council of Texas. Resource Integration
3
Electric Reliability Council of Texas. ERCOT Planning Guide – Section 5
4
Electric Reliability Council of Texas. ERCOT Fee Schedule
5
Electric Reliability Council of Texas. Optional, Final Ad Hoc Interim Voltage Ride-Through Assessment for Large Loads Requesting Initial Energization Before July 1, 2026
6
Public Utility Commission of Texas. PUCT Rule 25.195 – Terms and Conditions for Transmission Service
7
Electric Reliability Council of Texas. ERCOT Standard Generation Interconnection Agreement
8
Public Utility Commission of Texas. ERCOT Standard Generation Interconnection Agreement
9
ERCOT. ERCOT New Generator Commissioning Checklist
10
Electric Reliability Council of Texas. ERCOT Nodal Operating Guides
11
Electric Reliability Council of Texas. ERCOT Interconnection Process
12
Electric Reliability Council of Texas. ERCOT Large Load Update