Science & Tech

ERCOT Can Handle Texas Summer, Says Grid Expert; Nationwide Vulnerabilities ‘Much More Concerning’

Texas A&M Smart Grid Director Thomas Overbye doesn’t expect significant problems with the Texas power grid this summer, but says the entire nation is at risk from high-impact, low-frequency events.
By Lesley Henton, Texas A&M University Division of Marketing & Communications June 23, 2021

Wind Turbines and electricity power collection grid substation
Wind turbines and an electricity power collection grid substation

Getty Images


The energy conservation alert from the Electric Reliability Council of Texas (ERCOT) this month has caused concern that outages and rolling blackouts will wreak havoc like they did in February when an ice storm crippled the state, but a Texas A&M expert doesn’t expect any major issues this summer.

Instead, Thomas Overbye, director of the university’s Smart Grid Center, said he’s much more concerned by the potential vulnerability of the electric grids that power the entire country to what are called high impact, low frequency (HILF) events.

“There is always a risk of a blackout, but I don’t expect any significant problems this summer with the ERCOT grid due to the heat,” said Overbye, a professor of electrical and computer engineering. He said the alert was caused by a generation shortfall due, in part, by some unexpected forced generator outages of mostly fossil fuel units, as well as a higher-than-expected electric load.

“While concerning, particularly in light of the events from February, what occurred this month does not indicate any fundamental weaknesses or problems with the Texas electric grid,” Overbye said.

What does keep him up at night are vulnerabilities in the power grids that serve the entire nation and can turn events into catastrophes.

“Characteristics of HILF events include some combination of large size, long duration and potentially catastrophic societal impact,” he said. “HILF events can occur initially in the electricity grid and then spread to other sectors of society, start in another sector and spread to the electricity grid, or simultaneously affect both.”

Examples of HILF events include a physical attack on the grid, a cyberattack, geomagnetic disturbances, or severe weather events such as ice storms.

Overbye said two major events in 2020-2021 demonstrated threats to the grid, and that the results could have been much worse.

“The first event – as a positive example of reliable grid functioning – was the grid’s performance at the beginning of the COVID-19 crisis,” he said. “In the early days of the pandemic, when fear was widespread and store shelves emptied as many sheltered in place, the lights stayed on. That the grid worked as it was supposed to during this time was due in no small part to the dedication of the many individuals who keep our critical infrastructure running.”

But the second example showed what happens when the grid doesn’t function reliably, in this case due to record cold. “The grid in Texas faltered and appears to have almost collapsed,” Overbye said. “While the events of February were certainly bad, had the grid failed altogether, the results would most likely have been much worse.”

Overbye said we don’t yet know the specific causes of the generation shortfall that prompted ERCOT to issue this month’s conservation alert.

“It isn’t unusual to have some coal and natural gas generation unavailable due to what are called forced outages,” he said. “Usually it is about 5 percent of the generation and is often due to some equipment issue at the plant.”

Additionally, he said, the electric load was higher than expected because of the unusually high temperatures (at least for mid-June) that cause additional air conditioner loading. “ERCOT actually set an all-time record for their June load,” Overbye said.

At Texas A&M’s Smart Grid Center, Overbye and colleagues are working to ensure that outages such as February’s never occur again and Texans are able to enjoy air-conditioned summers.

“As a society we need do the research and development to understand, to simulate, and to develop mitigation strategies for such catastrophic events,” he said, adding that the Smart Grid Center has a number of projects specifically focused on improving electric grid resiliency, including one associated with improving the resiliency of the electric grid to cyberattacks and another aiming to improve the resiliency of the electric grid to geomagnetic disturbances.

For more information about the Texas A&M Smart Grid Center, visit

Media contact: Amy Halbert, Texas A&M College of Engineering,

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