No. For most of the state, Texas is not on the national power grid. About 90 percent of Texas electricity demand is served by the Texas Interconnection, an independent grid managed by the Electric Reliability Council of Texas (ERCOT) that covers more than 27 million customers.1Electric Reliability Council of Texas. ERCOT Grid Insights The continental United States otherwise runs on two large synchronous grids, the Eastern and Western Interconnections, and the Texas grid is deliberately kept separate from both. A few corners of the state are the exception, served by utilities that do connect to those national grids.
Why Texas Runs Its Own Grid
The split is a legal choice, not an accident of geography. In 1935, Congress passed the Public Utility Act, whose Title II (the Federal Power Act) gave the federal government authority over wholesale electricity sales that cross state lines.2Congressional Research Service. The Federal Power Act and Electricity Markets Texas utilities realized that if generation, transmission, and sales all stayed inside the state, federal regulators would have no jurisdiction over them.
The strategy stuck because the statute backs it. The Federal Energy Regulatory Commission (FERC) regulates interstate transmission and wholesale sales but has no jurisdiction over facilities used only for intrastate transmission.3Office of the Law Revision Counsel. 16 US Code 824 – Declaration of Policy; Application of Subchapter By never synchronizing with neighboring grids, Texas utilities stayed intrastate, and FERC acknowledges that ERCOT’s electricity markets fall outside federal jurisdiction. ERCOT instead answers to the Public Utility Commission of Texas and the Texas Legislature.4Federal Energy Regulatory Commission. An Introductory Guide to Electricity Markets Regulated by the Federal Energy Regulatory Commission
Parts of Texas That Are on the National Grid
Roughly 10 percent of the state’s electricity demand is served by utilities tied to the two national interconnections. Four investor-owned utilities operate outside ERCOT territory:5Public Utility Commission of Texas. Guide to the Electric Rate Case Process for Investor-Owned Utilities Outside ERCOT
- El Paso Electric serves the far western tip of Texas around El Paso and is part of the Western Interconnection.
- Southwestern Public Service Company (SPS) covers parts of the Texas Panhandle on grids outside ERCOT.
- Entergy Texas serves portions of deep East Texas and connects to the Eastern Interconnection.
- Southwestern Electric Power Company (SWEPCO) also covers parts of East Texas within the Eastern Interconnection.
Because these utilities operate across state lines or connect to interstate grids, they fall under FERC jurisdiction and follow federal reliability standards. Customers in those service areas were not affected by the ERCOT-specific failures during Winter Storm Uri in 2021, though some experienced outages from their own grids.
How Separate Is the ERCOT Grid?
The ERCOT grid is not completely walled off. It maintains four small direct current (DC) tie connections to non-ERCOT power systems.6Electric Reliability Council of Texas. DC Tie Flows A DC tie converts alternating current to direct current and back again, which lets power move between grids that aren’t synchronized with each other.
These ties exist for controlled, limited transfers rather than large-scale sharing. During normal operations they handle modest imports or exports, but their combined capacity is a small fraction of Texas’s peak demand, which can exceed 85,000 megawatts in summer. When the entire ERCOT grid is stressed, the ties cannot deliver enough electricity to close the gap. That limitation turned a hard winter into a disaster in February 2021.
What Grid Independence Cost During Winter Storm Uri
When an unprecedented winter storm pushed temperatures well below freezing across nearly all of Texas, the ERCOT grid came closer to total collapse than most Texans realized at the time. Over two consecutive days, an average of 34,000 megawatts of generation went offline, roughly 40 percent of the grid’s typical winter capacity.7North American Electric Reliability Corporation. The February 2021 Cold Weather Outages in Texas and the South Central United States More than 4.5 million people lost electricity, some for as long as four days, and the event caused numerous deaths.8Federal Energy Regulatory Commission. Final Report on February 2021 Freeze Underscores Winterization Recommendations
Freezing accounted for 44 percent of the generation that went offline, mostly through frozen instruments and sensing lines at power plants and icing on wind turbine blades. Another 31 percent of outages came from fuel supply problems, largely the inability to deliver natural gas to generators because gas production facilities and pipelines had also frozen.7North American Electric Reliability Corporation. The February 2021 Cold Weather Outages in Texas and the South Central United States The DC ties couldn’t import nearly enough power to make up the loss. ERCOT ordered rolling blackouts for nearly three consecutive days to prevent a complete collapse that could have taken weeks to restore.
What’s Changed Since
The Texas Legislature responded with Senate Bill 3 in 2021. It imposed mandatory weatherization on power plants and natural gas supply chain facilities in the ERCOT region, with penalties of up to $1 million for violations. The law also requires ERCOT to procure ancillary reliability services designed for extreme heat and cold, and it designates certain natural gas facilities as critical infrastructure that cannot be cut off during rolling blackouts.9Texas Legislature. Enrolled Bill Summary – Senate Bill 3, 87th Legislature
In 2023, Senate Bill 2012 authorized the Public Utility Commission to create a Performance Credit Mechanism, moving Texas closer to a capacity-market approach while keeping guardrails in place. Credits are limited to dispatchable generation (excluding battery storage and demand response), the total cost to the ERCOT market is capped at $500 million annually, and generators face buyback penalties if they fail to perform when called upon. The program cannot launch until ERCOT implements real-time co-optimization of energy and ancillary services.10Texas Legislature. Bill Analysis – Senate Bill 2012, 88th Legislature
None of these reforms changes the underlying structure. Texas still runs an independent grid with minimal ability to import power during emergencies. For residents in ERCOT territory, that is worth keeping in mind when thinking about backup power at home: your electricity supply depends almost entirely on in-state generation.