By Jennifer Hiller

A winter storm brought freezing temperatures to much of the U.S. two weeks ago and still holds much of the Northeast in its grip. Americans cranked up the heat, posing the biggest test of the electric grid this season. Here are some key takeaways:

Crypto powered down. Data centers didn't.

When the Arctic blast sent wholesale power prices soaring, cryptocurrency miners powered down their operations. Data centers for cloud computing and artificial intelligence kept using electricity at a high and steady rate, according to Wood Mackenzie.

The research and consulting firm has sensors that monitor the electromagnetic fields around transmission lines at sites across the U.S. They measure how much power is being devoured or generated at large data centers, manufacturers and power plants.

Worries are building about the sheer number of power-hungry data centers that will need to be built to drive the AI boom. Tech companies are debating utility executives about whether their electricity needs can be met without causing blackouts during times of extreme demand, and states including Texas are requiring more flexibility from large customers.

As data centers account for a larger percentage of total electricity demand over time, that could pose challenges for the grid. Utilities and grid operators often rely on nights, weekends and holidays for recovery and maintenance. They could lose those windows if more data centers are operating around the clock.

The data centers' behavior during the recent storm contrasts with last summer, when Wood Mackenzie found that many large data centers, crypto miners and factories from New York to Texas reduced their power use when temperatures rose. In some cases, their moves led to abrupt drops in wholesale power prices.

"It's not a one-size-fits-all for these data centers," said Rebekah Llamas, director of global power-market intelligence at Wood Mackenzie. "They pick and choose when they respond to demand to help support power markets."

A few factors could be at play.

Large power customers have a financial incentive to reduce electricity use in the summer, when demand peaks often determine what companies pay for the next year for delivery, a major component of their utility bills. Sophisticated customers try to reduce consumption at the peak times to lower their costs.

Summer extremes are shorter and more predictable, while in winter, freezes can last weeks and electricity use spikes twice a day, in the morning and evening. That can make it more difficult for customers to help the grid without jeopardizing their own operations.

Ahead of the storm, the Energy Department ordered grid operators to be prepared to take extraordinary steps to tap in to backup power generation at data centers or manufacturers.

Florida was one state where backup power recently came into play.

About 300 megawatts of backup generation was tapped in the state on Feb. 2 to help stabilize the grid, according to the Energy Department. Publix grocery stores were among the users that switched to on-site backup power, rather than relying on the grid.

Neighborhood lines were the weak link

Grid operators and utilities from the Midwest to New England to Florida managed tighter supplies and issued varying levels of alerts -- but avoided rolling blackouts. Orders from the Energy Department lifted some environmental rules to allow many generators to operate at full tilt, too.

The weak point emerged at the usual spot -- the smaller distribution lines and poles that carry electricity through cities and neighborhoods. Across the South, where ice accumulated instead of snow, hundreds of thousands of customers lost power.

About 8,000 customers still lacked electricity in northern Mississippi at the beginning of this week, according to the website PowerOutage.us. There, ice accumulation put thousands of pounds of weight onto power lines and tree branches.

New England switched to oil

The U.S. leaned on fossil fuels to get through the storm.

That was especially true in New England, where natural-gas generation and electricity imports from Canada and New York make up a large share of power supplies. Issues with delivery can worsen during periods of extreme cold. Many plants in the region can switch to oil instead.

Oil generated more than one-third of New England's electricity during the peak of the freeze, according to the Energy Department.

Coal and natural-gas use also surged. In the week that ended Jan. 25, coal-fired generation jumped 31% from the week prior in the Lower 48 states, according to the Energy Department. Natural-gas generation increased 14%. Output from solar, wind and hydropower dropped.

Soaring demand and frozen gas fields from West Texas to Appalachia led to a record drawdown in U.S. natural-gas supplies. More expensive gas will boost utility bills for the roughly 61 million U.S. homes that are warmed with natural gas, as well as the 57 million using electricity, much of which is generated by burning gas.

Texas grid held up

The Texas grid faced its most serious winter challenge since a 2021 disaster, when power blackouts contributed to the deaths of more than 200 people.

The grid fared well this time. It wasn't as cold for as long in Texas, and state regulators have required power generators and transmission infrastructure to better winterize. Some plants now store extra fuel on-site in case natural gas supplies become constrained. Battery-storage projects, which largely weren't around in 2021, can also help during brief periods of stress on the system.

Luck played a role as well. Cloud cover in North Texas and along the coast helped lower heating demand, according to the Electric Reliability Council of Texas, the grid operator for most of the state. Schools and businesses closed, too, reducing electricity use.

Write to Jennifer Hiller at jennifer.hiller@wsj.com

(END) Dow Jones Newswires

February 11, 2026 12:00 ET (17:00 GMT)

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