ERCOT
Texas Electricity Glossary
ERCOT (Electric Reliability Council of Texas) is the independent grid operator that manages electricity transmission across approximately 90% of Texas, serving about 26 million customers. ERCOT does not sell electricity to consumers — it runs the wholesale market where retail providers buy power, balances supply and demand in real time, and coordinates grid reliability. Because ERCOT operates almost entirely within Texas borders and is not connected to the broader U.S. grid, it functions as a unique electricity island governed by Texas rather than federal regulators.
What ERCOT Actually Does
ERCOT has two main functions. First, it operates the high-voltage transmission grid — directing electricity from generators (wind farms, natural gas plants, solar installations, nuclear stations) through the transmission network to the distribution lines owned by TDUs like Oncor and CenterPoint. Second, it runs the wholesale electricity market where retail electric providers bid for power on 15-minute intervals throughout the day.
ERCOT also manages ancillary services — reserve power capacity that can be called up within seconds or minutes when a generator trips unexpectedly. Paying for those reserves is part of why your bill includes charges beyond the per-kWh rate.
ERCOT's Boundaries — What It Covers and What It Doesn't
ERCOT covers the main Texas interconnect — Dallas, Houston, Austin, San Antonio, Corpus Christi, Lubbock, Midland/Odessa, and most of the state. It does not cover El Paso (on the Western Interconnection), the northeastern Texas panhandle counties (part of the Southwest Power Pool), or municipal utilities like Austin Energy and CPS Energy that opted out of deregulation. If you live in one of those areas, your electricity is not sold through ERCOT's competitive market.
How ERCOT Prices Affect Your Bill
Wholesale ERCOT prices fluctuate constantly — sometimes reaching the market cap of $5,000/MWh during heat waves, and occasionally going negative when wind generation floods the grid overnight. On a fixed-rate plan, your REP absorbs this volatility and locks your rate for the contract term. On a variable-rate plan, price spikes feed directly into your monthly bill. The catastrophic bills some Texans received after Winter Storm Uri in February 2021 were largely the result of variable-rate exposure during an ERCOT price emergency.
Who Regulates ERCOT?
ERCOT is overseen by the PUCT (Public Utility Commission of Texas) and the Texas Legislature. Because ERCOT is entirely intrastate, it is not subject to FERC (Federal Energy Regulatory Commission) oversight — a key reason Texas has handled its own grid regulation historically. Following Winter Storm Uri, PUCT significantly increased its oversight role over ERCOT's operations.
Related Terms
- PUCT — the state regulator that oversees ERCOT and licenses REPs
- REP — the company that buys from ERCOT and sells to you
- Load Zone — ERCOT's four pricing regions (Houston, North, South, West)
- Deregulated Electricity — the market structure ERCOT enables
- Fixed-Rate Plan — insulates you from ERCOT wholesale price swings
Compare plans across ERCOT: TexasPowerCost.com pulls daily data from the official Texas Power to Choose database — all plans in the ERCOT market for your ZIP. Enter your ZIP code to see true monthly costs calculated at your actual usage level.
Frequently Asked Questions
What does ERCOT stand for?
ERCOT stands for Electric Reliability Council of Texas. It is the independent system operator (ISO) that manages the flow of electricity across the high-voltage transmission lines serving about 90% of Texas — roughly 26 million customers.
How does ERCOT affect my electricity bill?
ERCOT runs the wholesale electricity market where retail providers (REPs) buy power. When wholesale prices rise — due to extreme heat, winter storms, or generator outages — REPs on variable-rate plans pass those costs to consumers immediately. Fixed-rate plan holders are insulated until their contract renews.
Is ERCOT the same as my electricity provider?
No. ERCOT does not sell electricity to consumers. Your retail electric provider (REP) buys power on the ERCOT wholesale market and sells it to you. ERCOT only manages the grid and the wholesale market — it never sends you a bill.