A deadly combination: No power and extreme heat. How likely is it and is Texas prepared?

Most Texas cities and counties would be unprepared to respond to a heat wave should it coincide with a power outage, experts who study extreme heat and the Texas power grid said.

As heat indexes across Texas are have soared, experts pointed to what happened in East Texas as a worst-case scenario: Parts of the region lost power for days when tornadoes swept through the transmission lines that deliver power to East Texas and Northwest Louisiana. In Harrison County, where more than 25,000 people were without power as of Wednesday, when heat index values were expected to reach 104.

Experts interviewed by the Star-Telegram said a grid collapse like what happened during the February 2021 winter storm would be unlikely to happen during the summer months, because the Texas grid is more equipped to handle extreme heat than extreme cold.

Instead, the real risk for power loss is at a more local level: The transmission and distribution systems that carry power from where it’s generated to customers’ homes and businesses. Disasters like tornadoes, wildfires or drought could cause serious damage locally, said Alison Silverstein, an independent energy consultant and former regulator with the Public Utility Commission and the Federal Energy Regulatory Commission.

“We are far more likely to have extended outages in the summer due to failures of the distribution and transmission system,” Silverstein said.

Power outages could also come from older parts of the grid, like if a distribution transformer were to overload and blow up, she said.

“Cities should be thinking about this,” said Andrew Dessler, a professor of atmospheric sciences at Texas A&M University. “If you’re not thinking about it, it’s like Houston not planning for a Category 5 Hurricane hitting it.”

Why we probably won’t see a catastrophe during the summer months

Although the threat of a grid collapse coinciding with a heat wave is a real one, Texas power grid experts agreed that such an event would be unlikely to happen.

The February 2021 storm left much of the state with power for days, and contributed to at least 246 deaths, although the true death toll could be higher. The event was precipitated by unusually low temperatures in the state, which caused Texans to use far more energy than ERCOT anticipated. That, coupled with natural gas plants freezing and other factors, caused millions of Texas to go days without power in freezing temperatures, said Joshua Rhoades, a research scientist at the University of Texas at Austin.

The Electric Reliability Council of Texas, or ERCOT, operates the power grid for most of the state. ERCOT directs and schedules the flow of power from the location where power is generated to customers, but it doesn’t own or operate power plants or power lines itself.

The Texas power grid is designed to generate only enough power to meet anticipated demand from customers. So if demand is forecast incorrectly, that could leave the grid in situations like on Tuesday, when ERCOT asked consumers to raise the temperatures on their thermostats and use less energy during peak hours.

If the grid was unable to lower demand voluntarily, it could ultimately resort to rolling blackouts, in which some customers could involuntarily lose power for a period of time, Rhoades said. But if that were to happen, it would be for a much shorter period than in 2021.

“Even if we did run out of power, it would not be as deep or as long,” as during the 2021 storm, Rhoades said.

So although a power grid collapse isn’t expected during the summer months, experts noted that anything was possible, and that even a local power outage, like the ongoing issues in East Texas, could be catastrophic during a Texas heat wave.

In Marshall, the county seat of Harrison County, a range of groups have responded to help residents get through the heat wave. The local pet adoption center opened its doors to serve as a cooling center for people and their pets on Tuesday. The county judge dump stations where residents could toss out the contents of their refrigerators and freezers as well as debris from the storm.

At least one person, a 35-year-old lineman from West Virginia, is believed to have died because of the extreme heat in East Texas. KETK TV reported that the power worker collapsed June 19 in his hotel room after working to restore power in the region. His official cause of death has not yet been determined, but officials told KETK they believe his death was heat related.

In Fort Worth, if a heat wave were to coincide with a widespread power outage, the city would “activate our Emergency Shelter plan and open one or more shelters as needed in coordination with our Non-Governmental partners,” a spokesperson for the city of Fort Worth said in a statement.

Why extreme heat is so deadly

At least 14 Tarrant County residents died from extreme heat last summer, although doctors who study heart health and the impact of heat said the true death toll was certainly much higher, because extreme heat can be so taxing on the heart. Of those who died from heat, at least eight cases included residents with no air conditioning, no working air conditioning, or who had their air conditioning turned off at the time of their death, according to the Tarrant County Medical Examiner’s Office. It’s too early in the summer to know how many people have died from heat in 2023, but emergency responders have already responded to 106 patients with a heat-related illness between May 1 and Tuesday, according to data from MedStar.

Although the majority of homes in Texas have air conditioning, at least a third of people living in the South reported difficulty paying their energy bills in 2020, according to the U.S. Energy Information Administration. So even if access to power stays consistent during a heat wave, low-income Texans with AC could still be vulnerable to extreme heat if they can’t pay their electric bills, Silverstein said.

The number of people killed by heat each year is an undercount, experts said, because that number usually only reflects the number of people killed by heat stroke, and not the people with other causes of death that were triggered by the heat. For the majority of people who die during a heat wave, it’s extreme heat’s impact heart that can cause fatalities. Hotter temperatures require the heart to pump blood more quickly in an attempt to keep the body’s core temperature stable, Dr. Sameed Khatana, a Philadelphia cardiologist who has studied extreme heat and health, told the Star-Telegram last year. For people with existing heart conditions, heat adds strain to an already burdened heart, and can make death from heart disease more likely.

Dessler, at Texas A&M, said more Texas cities needed to develop robust heat emergency plans, for extreme heat days with or without power. Some cities have plans that include cooling centers open around-the-clock and on-demand transportation for residents who need to get to a cooling center. Silverstein said that as climate change ensures that Texas summers will continue to get hotter and the weather more extreme, communities needed to invest in more detailed emergency management now.

“Unfortunately, the world is much riskier today than it used to be, because of climate-change driven weather and because of humans,” Silverstein said.