Will the power grid in frigid Texas be able to keep the heat on?

Millions of Texans who wake up to terribly cold air on Tuesday will hope that the state's power grid, which failed spectacularly during a 2021 deep freeze, can hold up this time.

The early hours of the day will be a crucial test for power supplies as wind chills dip below zero in cities like Austin, Dallas and San Antonio and as many offices reopen after the Martin Luther King birthday long weekend.

The operator of the state's grid, the Electric Reliability Council of Texas, has asked Texans to limit energy use Tuesday between 6:00 AM and 9:00 AM.

The council said the request “does not indicate that ERCOT is currently in an emergency situation,” adding that the request was a “common industry tool that can help reduce demand during a specific period of peak demand.”

Brutal winter weather in February 2021 knocked out Texas' power grid, causing millions to lose power for days and contributing to the deaths of more than 240 people.

Texas officials have taken steps to prevent such critical infrastructure from failing again as demand increases during the cold. Since 2021, the state has increased the amount of solar energy on the grid, in addition to large amounts of wind energy.

Even as officials remain confident in the strengthened power grid, ERCOT has not ruled out the possibility of rolling blackouts, where electricity to certain areas is cut off at a time and then restored. This emergency measure is intended to prevent demand from overwhelming the electricity grid and leading to widespread, long-term outages.

Winter mornings in particular place a strain on the electricity grid. Temperatures are near the lowest; the wind, which drives the electric turbines, is often silent; and the sun, which powers the solar panels, is not strong enough.

Several Texas mayors implored residents to take precautions in the extreme cold. In Austin, warming shelters were expected to operate through Tuesday morning after housing 400 people overnight, many of whom were vulnerable homeless people at risk of hypothermia.

“It's very, very cold,” Austin Mayor Kirk Watson said Monday.

Classes were canceled Tuesday in some populous school districts, including Dallas, and on some major college campuses, such as Texas A&M, and that could reduce expected electricity demand.

So far the system has survived the last deep freeze. ERCOT said there were no outages Monday morning as electricity use surpassed a previous winter peak demand record set during the December 2022 cold snap. But Tuesday's surge could be greater.

a forecast by ERCOT It is estimated that if temperatures in January fall as low as they did in December 2022, there would be about a one in six chance of blackouts occurring during the mornings around 8am

And while much of the focus is on Texas, it is far from the only place where there is hope that crucial utility infrastructure will not collapse under the pressure of the cold weather.

In 2021, while millions of Texans were without electricity, many people in Mississippi's capital, Jackson, without water for weeks. And at Christmas in 2022, tens of thousands of people in Jackson had no running water because the system's pipes could not withstand the freezing temperatures.

One of Jackson's water plants was built in 1914, and some of the city's water problems date back to when the city's infrastructure existed. As subzero temperatures become more common in the South, infrastructure not built for such cold has become vulnerable.

“We've made many improvements to facilities that were never built for cold weather,” said Ted Henifin, the city's interim manager of the drinking water system. “We feel good about where we are now.”

David Montgomery contributed reporting from Austin, Texas.