Texas data centers raise blackout risk during extreme winter weather

The rapid expansion of data centers in Texas is driving electricity demand higher during the winter, compounding the risk of supply shortfalls that could lead to blackouts during freezing temperatures.

The Lone Star state is attracting a huge amount of data center requests, driven by its abundant renewable energy and natural gas resources as well as its business friendly environment. OpenAI, for example, is developing its flagship Stargate campus in Abilene, about 150 miles west of Dallas-Forth Worth. The campus could require up to 1.2 gigawatts of power, the equivalent of a large nuclear plant.

The North American Electric Relibaility Corporation warned this week that data centers’ round-the-clock energy consumption will make it more difficult to sustain sufficient electricity supply under extreme demand conditions during freezing temperatures like catastropic Winter Storm Uri in 2021.

“Strong load growth from new data centers and other large industrial end users is driving higher winter electricity demand forecasts and contributing to continued risk of supply shortfalls,” NERC said of Texas in an analysis published Tuesday. Texas faces elevated risk during extreme winter weather, but the state’s grid is reliable during normal peak demand, NERC said.

During Uri, demand spiked for home heating in response to the freezing temperatures at the same time power plants failed in large numbers due to the same weather. Texas grid operator ERCOT ordered 20 gigawatts of rolling blackouts to prevent the system from collapsing, according to a Federal Energy Regulatory Commission report. The majority of the power plants went offline ran on natural gas.

It was the “largest manually controlled load shedding event in U.S. history” resulting 4.5 million people losing power for several days. At least 210 people died during the storm. Most of the fatalities were connected to the outages and included cases of hypothermia, carbon monoxide poisoning, and medical conditions exacerbated by freezing termperatures, according to FERC.

In the years since Uri, Texas has received a staggering amount of requests from data centers, crypto mining facilities and industrial customers seeking a grid conenction. More than 220 gigawatts of projects have requested connection as of this month, a 170% increase over the 83 gigawatts of project requests back in January, according to data published Wednesday by ERCOT.

About 73% of the projects requesting connection are data centers, according to ERCOT.

If all of those projects were actually built, they would be equivalent to the average annual power consumption of nearly 154 million homes in Texas, according to a CNBC analysis based on 2024 household electricity data. But the Lone Star state only has a population of about 30 million people.

Beth Garza, a former head of ERCOT’s watchdog, said she is very skeptical these projects will all get built, describing the scale of the numbers as “crazy big.” More than half the projects have not submitted planning studies, according to ERCOT.

“There’s not enough stuff to serve that much load on the equipment side or the consumption side,” said Garza, who served as director of ERCOT’s Independent Market Monitor from 2014 through 2019. “There’s just so much stuff in the world to make those kinds of numbers work.”

Phantom data centers are showing up in grid connection requests across the U.S. as developers shop the same projects around to mutliple jurisdictions, said John Moura, the director of NERC’s reliability assessments. This makes it difficult for utilities to forecast future demand conditions.

The projects that ERCOT has approved to actually connect to the grid is much smaller at 7.5 gigawatts, but this is still a subsantial amount of new demand. By comparison, the six county region in southeastern Pennsylvania that includes Philadelphia, with a population of 1.7 million people, had a peak demand of about 8.6 gigwatts in 2024, according to the state utility board.

Texas’ supply and demand balance can become tight during winter and potentially fall into deficit. The state has 92.6 gigawatts of available resources and peak demand in an extreme Uri-like scenario could reach about 85.3 gigawatts, according to NERC.

But avalaible power could fall to around 69.7 gigawatts in extreme winter weather, leaving a supply deficit of more than 15 gigawatts. This is due to typical power plant maintainence and forced plant outages as well as reductions in power capacity due to winter conditions.

“What’s important to understand is the tightness we’re seeing,” Moura said. NERC’s winter assessment only included data center facilities that have reached certain milestones to filter out speculative projects, he said.

“I can’t stress enough how much of a monumental change this is for the electric industry,” Moura said of the data center requests. One solution is for data centers to show flexibility in their electricity consumption to help keep demand and supply in balance during extreme winter scenarios, he said.

In the case of Uri, natural gas plants made up 58% of all the unplanned outages in Texas, according to FERC. Freezing tempartures reduced gas production, led to challenges delivering fuel and problems transmitting electricity as power lines fell.

Texas has adopted rules to harden natural gas infrastructure for extreme winters in the wake of the storm.

When gas plants go out in such a large way, solar and battery storage also face challenges, according to NERC. Peak demand in winter is in the early morning hours when sunlight is lower and batteries may not have had enough time recharge, Moura said.

With data centers running around the clock, “maintaining sufficient battery state of charge will become increasingly challenging for extended periods of high loads, such as a severe multi-day storm like Winter Storm Uri,” NERC said in its analysis.

“Power shortfalls and rolling outages really could happen in the next few years in certain regions” of the U.S. as demand from facilities like data centers outstrips supply, said Rob Gramlich, president of power consulting firm Grid Strategies. “Those are unacceptable to everybody in the United States.”

Garza said she’s confident that the reliable demand from data centers will bring new supply. “Plants love that kind of of opportunity,” she said. “My expectation is that then attracts additional private capital investment to meet those supply needs.”