Impact of extreme weather events on electricity grids and the customers who depend on them

Extreme weather is causing power grid outages across the country, sometimes on a large scale, putting residents at increased health risk, as scientists predict an increase in the frequency of severe weather events in the future.

The effects of global warming are worsening in every region of the United States, according to the Fifth National Climate Assessment, an analysis of the latest climate science from 14 different federal agencies, released in November.

“You can see the trend, and there is an increased frequency of extreme events because of climate change,” Max Zhang, an engineering professor at Cornell University, told ABC News.

Data shows that increasing extreme weather events are leading to more power outages.

In the United States, the number of disruptions increased by 16% in 2022 compared to 2013 for the average person. The Associated Press reported, citing data from the Energy Information Administration.

Of all major power outages in the United States reported between 2000 and 2023, 80% (1,755) were due to weather, according to a 2024 report from Central Climatea nonprofit climate science information organization.

“The magnitude of the storm can really determine the magnitude of the outage,” Mike Jacobs, senior energy analyst at the Union of Concerned Scientists, told ABC News.

When power goes out, it’s usually not because the grid doesn’t have enough power, but rather because there are difficulties getting electricity to customers, says Daniel Cohan, an associate professor of environmental engineering at Rice University in Houston.

This is usually because transmission and distribution lines are disrupted by a series of events, including severe storms, lightning strikes, high winds or even severe wildfires, Cohan said. Tornadoes, floods and winter storms with ice and snow can also impact power lines, Zhang said.

One exception occurred during the 2021 Texas freeze, when millions of homes lost power due to frigid temperatures. In that case, there actually wasn’t enough electricity to go around, especially after more than half of the state’s natural gas infrastructure experienced unplanned outages, according to a report from the Federal Energy Regulatory Commission published in November 2021 found.

Widespread outages of this magnitude are actually quite rare, Cohan said, adding that outages tend to happen neighborhood by neighborhood.

According to the Climate Central report, most weather-related power outages between 2000 and 2023 were caused by extreme weather (58%), winter storms (23%) and tropical cyclones, including hurricanes (14%).

While extreme heat is not a direct cause of power grid outages, it does reduce the efficiency of power lines, Cohan said. In addition to that reduced efficiency, customers often use more electricity to cool their homes. This is an example of “compound risk” — in which multiple threats to the power system occur at once — but the likelihood is low, Zhang said.

Drought can also impact power grids, leaving less water available for cooling operations, particularly at thermal power plants that generate energy from coal, natural gas or nuclear power, Cohan said. Drought can also set the stage for devastating wildfires that can take down power lines, Zhang said.

The longer the power outage lasts, the more dangerous it is to human health, especially for residents with underlying health conditions, experts said.

Hundreds of people died when power went out during the 2021 Texas freeze, while heat is the leading cause of weather-related deaths in the United States, according to the Centers for Disease Control and Prevention.

The United States has been hit by two hurricanes so far this season — Hurricane Beryl in Texas in July and Hurricane Debbie in Florida in early August — and it took “much longer” — nearly a week — for Texas homes to get power back, Cohan said.

“I think it’s something that needs to be looked at carefully after the fact: Why did Texas utilities … take as long as some of their counterparts in Florida to get their systems back online?” Cohan said.

According to Climate Central, the states with the most weather-related power outages reported between 2000 and 2023 were Texas (210), Michigan (157), California (145), North Carolina (111) and Ohio (88).

At least 50% of outages caused by major events from 2017 to 2021 lasted more than 12 hours, while 36% exceeded 24 hours, according to a report by the Swiss Federal Office of Electricity (FOEN). National Renewable Energy Laboratory.

While it is unrealistic to aim to avoid 100% of power outages, state lawmakers and utility commissioners must ensure the resilience and integrity of systems so people do not experience unnecessary suffering, Cohan said.

“How can we improve responsiveness, so that more people can get back online more quickly?” Cohan asked. “Before their food rots in the refrigerator, or before they really suffer from heat or cold issues at home for days on end.”

Utility companies must maintain existing systems, many of which are at least 50 years old, Cohan said. Simple fixes like replacing wooden poles and other decades-old equipment or trimming surrounding vegetation are possible. But repairs must be done regularly, Jacobs said.

Other methods of modernizing or optimizing power lines, such as burying them underground, are often not feasible or too expensive.

“It’s not going to be possible to invest in burying lines everywhere,” Cohan said. “But we could look at places that are particularly vulnerable to wildfires, particularly vulnerable to hurricanes, where those investments might make sense.”

Zhang said it is up to homeowners to protect their homes from the elements, including sealing leaky walls and windows and installing insulation. This, experts say, will allow homes to maintain a comfortable temperature for hours after a power outage.

“Insulation and weatherstripping help you weather warm weather,” Jacobs said. “They help you weather cold weather.”

But mitigating climate change through increased use of renewable energy will ultimately be the deciding factor in whether the frequency of extreme events continues to increase, Zhang said.

“We need to reduce greenhouse gas emissions,” he said.