Texas power outages: what happened in 2021, and how to get through the next one

The timeline below comes from the University of Texas at Austin Energy Institute report (July 2021). It puts all times in Central Standard Time.

Sources give different figures for the size of the outage. ERCOT and UT both give the peak controlled outage as 20,000 MW. The federal staff report from FERC, NERC and the regional entities calls it the largest firm load shed event in U.S. history and gives 23,418 MW. The same federal report found that for more than two days ERCOT averaged 34,000 MW of generation outages, close to half of its winter peak record of 69,871 MW at the time. ERCOT reports that about 48.6% of its generation was forced offline at the worst point.

The federal staff report made 28 recommendations, including mandatory cold-weather standards for generators and winterization of natural gas infrastructure. By December 2022, FERC staff reported that new generator freeze-protection standards had been filed and that the Railroad Commission of Texas had adopted a rule requiring cold-weather preparedness plans for natural gas facilities. These rules lower the risk of a repeat but do not remove it, so a household plan still matters.

ERCOT (the Electric Reliability Council of Texas) says it serves about 90% of the state's electric load and manages power for more than 27 million Texas customers. It is a nonprofit overseen by the Public Utility Commission of Texas (PUC) and the Texas Legislature. Some parts of Texas are on other grids, so check which grid serves you.

Most of Texas is on its own grid. The UT Energy Institute describes ERCOT as a fully intrastate system with only a few small direct current links to neighboring grids. ERCOT's 2026 emergency overview lists imports from neighboring grids of up to 1,220 MW during an emergency. That is small next to a shortfall like 2021's. The federal report recommended studying more connections and proposed links of 2,000 MW to the Eastern grid and 1,500 MW to the Western grid.

ERCOT orders controlled outages, but it does not choose which neighborhoods go dark. It gives each local utility a share of the cut, based on that utility's past peak demand, and each utility decides how to meet it. ERCOT says it has no oversight of those local outage plans. The company that owns the poles and wires (your transmission and distribution utility, such as Oncor, CenterPoint, AEP Texas or TNMP) handles your outages, not the retail company you pay. In a co-op or city utility area, the co-op or city handles them.

Before Uri, ERCOT described rotating outages as usually lasting 10 to 45 minutes before moving to another area. In 2021 that did not happen for many people. ERCOT later told its board that utilities could not rotate outages well because so much generation was lost and so many circuits carried critical loads, such as hospitals. Plan for an outage that lasts days, not one that rotates every hour.

ERCOT lists four times it has ordered controlled outages: December 22, 1989 (500 MW), April 17, 2006 (1,000 MW), February 2, 2011 (4,000 MW) and February 15 to 18, 2021 (20,000 MW).

ERCOT sends public notices through TXANS, the Texas Advisory and Notification System. There are three public steps, and they are separate from the emergency levels used by grid operators.

When ERCOT asks for conservation and it is safe for your household, it suggests moving the thermostat a degree or two, turning off extra lights, and holding off on washers, dryers and dishwashers. If someone at home is medically fragile, very young, or elderly in extreme heat or cold, keeping them safe comes before conserving.

DSHS found that 25 of the Uri deaths came from pre-existing illness made worse by the storm. These included interrupted dialysis or oxygen, frozen medical devices and medicine, and loss of power to life-sustaining equipment. Two separate registrations can help, but neither one keeps the power on.

⚠ The PUC form says plainly that this status does not guarantee uninterrupted power. If you need electricity to stay safe, you need a backup power source or a place to go. Designated customers can still lose power during controlled outages, and the status does not stop disconnection for unpaid bills.

As of February 17, 2021, Texas Commission on Environmental Quality (TCEQ) head Toby Baker reported that 332 water systems in 110 counties had problems and that 276 had issued boil-water notices. NPR reported that about 7 million Texans had to boil their water at that point. The causes included treatment plants without power, frozen and broken pipes, and pressure too low to keep the water safe. Be ready for your tap water to stop or become unsafe during a long freeze, even if your home has power.

If your water system issues a boil-water notice, follow it until the system lifts it. The main guide's water chapter covers how to make water safe.

DSHS confirmed 19 carbon monoxide deaths from Uri. The causes it named were generators, grills, heaters and vehicles run in enclosed spaces, plus ice blocking the vents of gas heating equipment. Another 10 people died in fires, some from space heaters too close to things that could burn. Hypothermia was the largest cause of death, with 158 deaths. DSHS found that about two thirds of those who died of hypothermia were 60 or older. Other risk factors it named were doing repairs outdoors during the storm, not dressing warmly enough, being homeless, and refusing to go to a warming center.

⚠ If a CO alarm sounds or several people in the house feel sick at once, get everyone outside into fresh air and call 9-1-1.

If your home cannot be kept warm, call 2-1-1 or search 211texas.org for warming centers and shelters. Check on older neighbors in person, not only by phone, since phones die in long outages.

Texas now uses the most power in summer. ERCOT lists an unofficial all-time demand record of 91,089 MW on July 22, 2026, up from 85,508 MW on August 10, 2023. ERCOT says each megawatt serves about 250 homes at peak. Conservation requests are most likely on hot late afternoons and evenings. An outage during a heat wave is a health emergency, not just an inconvenience.

If the power goes out in a heat wave, get the most vulnerable people to a cooling center, a library, or a friend's home that has power early, before symptoms start. Generators in summer bring the same carbon monoxide risk as in winter.