Why does Texas have its own power grid?

Updated October 24, 2026

General information, not a substitute for the advice of an attorney.

Short answer: Because the lower 48 states are split into three interconnections, and most of Texas is its own: the Electric Reliability Council of Texas (ERCOT). The three grids mostly operate independently and rarely exchange power (EIA). ERCOT serves about 90 percent of Texas load and more than 27 million customers, and it answers to the Public Utility Commission of Texas and the Texas Legislature rather than to a federal market regulator (ERCOT fact sheet, April 2025).

The three interconnections

EIA describes the Eastern Interconnection as everything east of the Rocky Mountains plus part of the Texas panhandle, the Western Interconnection as the Rockies westward, and ERCOT as most of Texas. The Eastern and Western grids are also linked to Canada (EIA, delivery to consumers). The parts of Texas outside ERCOT, such as the panhandle, belong to the other two grids, which is why ERCOT's share is about 90 percent rather than all of the state (ERCOT).

What makes ERCOT different

One organization does three jobs. EIA notes that ERCOT is unique because its balancing authority, its interconnection, and its regional transmission organization are the same entity (EIA).
State oversight. ERCOT is a membership-based 501(c)(4) nonprofit subject to oversight by the Public Utility Commission of Texas and the Texas Legislature, which restructured the market in 1999 (ERCOT).
Scale. More than 54,100 miles of high-voltage transmission, 1,250 or more generating units, 1,873 or more market participants, about 75% of load served through competitive retail choice, and a peak demand record of 85,508 MW set August 10, 2023 (ERCOT).
Limited ties. ERCOT's fact sheet reports DC-tie capacity and net DC-tie imports and exports in its energy accounting, meaning its connections to neighboring grids are direct-current links rather than synchronous AC ties; the fact sheet does not list how many there are or where they go (ERCOT).

What that does and does not mean

The federal reliability framework still applies: NERC writes mandatory reliability standards and FERC approves them, and those standards cover ERCOT (EIA). The FERC and NERC investigation of the February 2021 outages treated ERCOT alongside SPP and MISO South (FERC). What ERCOT avoids is federal wholesale-market and transmission-rate jurisdiction that comes with interstate AC interconnection; the primary sources opened for this page describe the state-oversight structure but do not spell out the legal history of that exemption, so this page does not either.

The practical consequence is the one Texans saw in 2021: a grid that rarely imports much from its neighbors has to cover its own shortfalls.

See what ERCOT is, the ERCOT queue, grid interconnection by market, and outage history by county and ZIP.