Texas power outage: why natural gas fell during the winter storm

Failures in Texas’ natural gas operations and supply chains due to extreme temperatures are the most significant cause of the energy crisis that left millions of Texans without heat and electricity during the winter storm that sweeps across the U.S.

From frozen natural gas wells to frozen wind turbines, all sources of power generation faced difficulties during the winter storm. But Texans rely heavily on natural gas for power and heat generation, especially during peak usage, experts say.

Officials at the Texas Electric Reliability Council, or ERCOT, which manages most of the Texas power grid, said the main cause of the outages on Tuesday appeared to be the state’s natural gas suppliers. Many are not designed to withstand these low temperatures on equipment or during production.

According to some estimates, almost half of the state’s natural gas production has been halted due to extremely low temperatures, while the freezing of components in plants powered by natural gas has forced some operators to close.

“Texas is a gaseous state,” said Michael Webber, professor of energy resources at the University of Texas at Austin. Although he said that all Texas energy sources share the blame for the energy crisis – at least one nuclear plant has been partially closed, mainly – the natural gas industry is producing significantly less energy than normal.

“The gas is failing in the most spectacular way right now,” said Webber.

More than half of ERCOT’s winter generation capacity, largely powered by natural gas, was shut down due to the storm, about 45 gigawatts, according to Dan Woodfin, senior director of ERCOT.

The interruptions during the storm far exceeded what ERCOT had predicted in November for an extreme winter event. The forecast for peak demand was 67 gigawatts; peak usage during the storm was over 69 gigawatts on Sunday.

It is estimated that about 80% of the network’s capacity, or 67 gigawatts, could be generated by natural gas, coal and some nuclear power. Only 7% of ERCOT’s predicted winter capacity, or six gigawatts, was expected to come from various sources of wind power across the state.

Woodfin said Tuesday that 16 gigawatts of renewable energy generation, mainly wind power, are offline and that 30 gigawatts of thermal sources, which include gas, coal and nuclear power, are offline.

“It appears that much of the generation that went offline today was mainly due to problems with the natural gas system,” Woodfin said during a call with reporters on Tuesday.

Production of natural gas in the state has fallen, making it difficult for plants to obtain the fuel needed to operate them. Natural gas plants generally do not have much fuel storage on site, experts said. Instead, mills rely on the constant flow of natural gas from pipelines that run through the state from areas like the Permian Basin in western Texas to major demand centers like Houston and Dallas.

In early February, Texas operators produced about 24 billion cubic feet a day, according to an estimate by S&P Global Platts. But on Monday, Texas production plunged to a fraction of that: operators in the state produced somewhere between 12 and 17 billion cubic feet a day.

Systems that obtain gas from the earth are not built properly for cold weather. Operators in the Permian Basin of western Texas, one of the most productive oil fields in the world, are particularly struggling to bring natural gas to the surface, analysts said, as cold and snow closes wells or causes power outages that prevent pumping fossil fuels from the ground.

“The collection lines freeze and the wells are so cold that they cannot produce,” said Parker Fawcett, a natural gas analyst at S&P Global Platts. “And the pumps use electricity, so they are not even able to lift the gas and liquid, because there is no energy to produce.”

Texas does not have as much storage capacity as other states, experts say, because the resource-rich state can easily pull it out of the ground when needed – usually.

From the state’s storage, resources are somewhat difficult to obtain. Luke Jackson, another natural gas analyst at S&P Global Platts, said that physically withdrawing stored natural gas is slower than immediate supply of production lines and is insufficient to compensate for dramatic declines in production.

Some plants were already shut down before the crisis started, adding to the problems, experts said. ERCOT has predicted four gigawatts of maintenance outages during the winter. Power plants in Texas generally maintain and upgrade their plants during the typically mild winter months in preparation for extreme electricity and energy demand during the summer. This is also putting a strain on the supply of the network.

Another winter problem: heating homes and hospitals by burning natural gas.

“In the summer, you don’t have so much direct burning of natural gas,” said Daniel Cohan, associate professor of civil and environmental engineering at Rice University, pointing out that during peak usage during the summer months, the demand is total for electricity.

The last time the state experienced a major freeze like this was a decade ago, in 2011. At that time, too, natural gas generation faced difficulties – if ERCOT had not reduced the load through the blackouts implemented during the storm, it would have resulted in widespread blackouts throughout the region, warned a federal storm report.

It is possible to “prepare for winter” natural gas plants, natural gas production and wind turbines, experts said, which avoids major disruptions in other states with more regular extreme winter. However, even after the updates were made after the 2011 winter storm, many Texas power generators have yet to make all the necessary investments to avoid the type of equipment disruptions that happen, experts said.

ERCOT directors also said that this week’s storm changed in the early hours of Monday morning, when extremely low temperatures forced many more generators to shutdown than ERCOT had predicted.

“It looked like the winter preparation we were doing was working, but that weather was more extreme than (past storms),” said Woodfin. “The loss of generation during Monday morning, after midnight, was really the part that made this event more extreme than we had planned.”

Upgrading equipment to withstand extremely low temperatures and other changes, such as providing incentives for customers to conserve energy or upgrading to smart devices, can help prevent disasters like this, said Le Xie, professor of Electrical and Computer Engineering at Texas A&M University and director energy digitalization assistant at A&M Energy Institute.

“We used to not worry too much about this extreme cold in places like Texas, but we probably need to prepare for more in the future,” said Xie. With climate change, he said: “We will have more extreme weather conditions across the country.”

– Jolie McCullough contributed reporting.

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