The Texas grid, from the top
What is ERCOT
The Electric Reliability Council of Texas runs the grid for about 90% of the state. Right now it's serving 76.2 GW of demand (8:40 PM CT, live). Here's what it does, who oversees it, and why its four summer peaks show up on your power bill.
What is ERCOT?
ERCOT, the Electric Reliability Council of Texas, is the independent system operator for the grid that serves about 90% of Texas's electric load. It schedules power across the state's generators and transmission lines, runs the wholesale electricity market, and keeps supply matched to demand second by second. It's a nonprofit, overseen by the Public Utility Commission of Texas and the Texas Legislature.
Is ERCOT an ISO or an RTO?
An ISO, one of nine independent system operators in North America. The ISO/RTO distinction matters little in practice. ERCOT does for Texas what PJM or MISO do for their regions: operate the grid and run the market, without owning power plants or wires.
Does ERCOT cover all of Texas?
No. El Paso is on the Western Interconnection, the upper Panhandle and parts of Northeast Texas are on the Southwest Power Pool, and slices of East Texas sit in MISO. Our live Texas map draws the state line around the ERCOT zones so you can see exactly what's in and what's out.
Why does Texas have its own power grid?
By staying almost entirely inside state lines, the Texas grid avoids most federal jurisdiction over wholesale electricity, a deliberate choice that dates to the 1930s. ERCOT connects to neighboring grids only through a handful of small DC ties, which is also why Texas can't import much power in an emergency.
Does ERCOT generate power or own transmission lines?
Neither. Generators, utilities, and cooperatives own the physical assets. ERCOT coordinates them: it dispatches generation, operates the wholesale market, and settles the payments.
Does ERCOT have a capacity market?
No. ERCOT is an energy-only market. Generators earn money only when they sell energy, with administrative price adders that push prices up sharply as reserves get scarce. That design is why real-time prices can swing from below zero to thousands of dollars per megawatt-hour.
How is ERCOT funded?
Through a small system administration fee on the electricity that flows through the market, not taxes. The fee is set with PUCT oversight.
What are ERCOT's 4CP peaks, and why do they cost so much?
The single highest 15-minute demand interval in each of June, July, August, and September. Those four coincident peaks decide how hundreds of millions of dollars of transmission costs get allocated for the following year. A large facility that's off during those four intervals pays dramatically less. Knowing which afternoons matter is the hard part, and it's the problem this site exists to solve.