If you’ve had a Texas electricity bill in the last five years, you’ve heard ERCOT mentioned — usually in the context of a heat wave, a freeze, or a controversy. Here’s what ERCOT actually is, what it does, and why understanding it matters for the bill you pay every month.
What ERCOT is
ERCOT — the Electric Reliability Council of Texas — is a non-profit organization that operates the electric grid for the part of Texas that runs on its own grid. That’s about 90% of the state’s load and 26 million people. The other 10% (El Paso, parts of the Panhandle, parts of East Texas near Louisiana) sit on the Western Interconnection or the Eastern Interconnection respectively.
ERCOT’s job: keep the lights on. It schedules generation in real time to match demand, runs the wholesale market where power plants sell electricity, and manages emergency operations. It does not own generation, doesn’t own transmission lines, and doesn’t sell electricity to consumers. It’s overseen by the PUCT and, after 2021, by the Texas Legislature directly.
Why Texas has its own grid
Texas’s grid isolation is a deliberate 1930s decision. By keeping its grid disconnected (with only limited DC interconnections to neighboring grids), Texas avoided federal jurisdiction under the Federal Power Act. That means Texas regulators control the market design, not Washington — and it’s why the 1999 deregulation and the 2021 post-Uri reforms could happen at the state level without federal review.
The cost of that isolation: when Texas runs short of generation, it can’t easily import power from neighboring states. The DC interconnects to the Eastern Interconnection at the Oklaunion and Welsh substations top out around 1,200 MW combined — meaningful, but not enough to rescue a 90 GW grid in crisis.
The "energy-only" market
ERCOT runs an energy-only market: generators get paid only for the electricity they actually sell into the wholesale pool. There’s no separate capacity payment for being available. The PUCT-set price cap is $5,000/MWh as of 2026 (down from $9,000/MWh pre-Uri). When prices spike toward the cap, that’s the market’s signal that supply is scarce — and it’s how Texas funds new generation investment without a regulated capacity market.
The trade-off: when the price cap hits and stays there, retail customers on indexed or pass-through products get crushed. Which is exactly what happened in February 2021.
Winter Storm Uri (February 2021)
From February 13–17, 2021, an unprecedented cold air mass dropped Texas temperatures into single digits across the state. Demand spiked to ~76 GW. Generation collapsed: roughly 30 GW of capacity (gas, coal, wind, even one nuclear unit) tripped offline due to frozen equipment, fuel supply failures, and cold-weather inflexibility. ERCOT ordered controlled outages that ultimately left 4.5 million Texans without power, some for several days. Hundreds died, mostly from hypothermia and carbon monoxide poisoning from improvised heating.
Uri wasn’t a market failure in the sense that the rules didn’t work — the rules worked exactly as designed. It was a planning and winterization failure that revealed how thinly the system was operating.
For five days, ERCOT held wholesale prices at the $9,000/MWh cap. Retail customers on variable or indexed plans saw single-month bills of $5,000–$15,000. Texas Senate Bill 3 (2021) responded with mandatory winterization of generation, new emergency-pricing rules, and a ban on residential indexed-rate products that pass through real-time wholesale spikes.
What’s changed since
The 2026 ERCOT looks materially different from the 2020 version: winterization audits are mandatory, the price cap has been lowered, reliability assessments are more conservative, and battery storage has grown from near-zero to over 6 GW. Reserve margins remain the central worry — ERCOT’s 2026 summer assessment shows a 13.7% margin against a 13.75% target. Tight, but not red.
What this means for you
You don’t buy electricity from ERCOT. You buy from a REP that buys from ERCOT’s wholesale market. The takeaway: when you see news about ERCOT prices spiking or reserve margins tightening, your bill is only affected if you’re on a variable or indexed plan. Fixed-rate customers locked their price before the spike. Lock a fixed-rate plan and the next ERCOT headline becomes someone else’s problem.