Power plants that burn coal and natural gas to produce electricity had significant drops in generation as a winter storm hit the US Southeast, forcing blackouts that left hundreds of thousands in the dark.
Duke Energy Corp. and the Tennessee Valley Authority cut power to homes and businesses during the holiday season as an extreme winter storm pummeled the region. Duke instituted rotating outagesDec. 24 that interrupted service to about 500,000 customers, while TVA for the first time in its history had rotating blackouts Dec. 23 and Dec. 24.
The disruption was the latest instance of a major failure to generate electricity in the US following a storm or natural disaster, a trend that’s brought attention to the state of the nation’s energy infrastructure and its dependence on fossil fuels to keep the lights on even as the Biden administration advocates for a transition to renewable energy.
The failure of coal and gas highlights how even the power sources that have long served as the backbone of the US electrical grid can still falter, especially as the South sees its population increase and relies more on electric heat.
TVA saw power generation from coal plants drop about 68% from more than 4 gigawatts early Dec. 23 to a low of about 1.5 gigawatts on Dec. 24, according to federal data. While gas generation increased Dec. 23, on Dec. 24 it fell roughly 25% from about 11.5 gigawatts to less than 9 gigawatts as the utility ordered outages for almost six hours.
High winds damaged several of the protective structures at the Cumberland Fossil Plant, the biggest TVA coal plant, as well as multiple gas-fired combustion turbines used during peak power periods, a TVA representative said in an email.
Read more: Top US gas supplier EQT saw output drops of 30%
Duke also saw its gas generation drop off just when it was needed most, according to federal data. Generation from its plants fell about 42% from more than 6.6 gigawatts to a low of about 3.8 gigawatts on Dec. 24, the day it instituted outages.
The weather caused a reduction in Duke’s generation and extra electricity couldn’t be brought in from other power producers or from out of state because those utilities were also facing shortages, a Duke representative said in an email Thursday. And some of Duke’s generation was also offline due to planned or maintenance outages unrelated to the storm.
The Tennessee Valley Authority holds the capacity for nearly 34 gigawatts of nuclear, fossil fuels and renewables. That capacity is supposed to hold up in worst case scenarios like Arctic blasts.
When temperatures dropped to single digits across Tennessee last weekend, however, some of that fossil fuel generation froze, triggering rolling blackouts.
This all happened as Tennessee set new records for electricity demand. TVA reported its highest winter peak demand of 33.4 gigawatts at 7 p.m. on Friday, Dec. 23, and the highest 24-hour electricity demand that day with 740 gigawatt-hours.
At the same time, two coal plants, the Cumberland Fossil Plant and the Bull Run Fossil Plant, were at least partially down.
TVA said there were issues at gas plants but did not provide details about the specific plants or how they were impacted during the storm. Winter weather can impact the entire natural gas system, from frozen drilling equipment and pipelines to plant failures.
“We have not seen much transparency out of TVA,” said Daniel Tait, COO of the nonprofit Energy Alabama. “We would argue and expect a lot more open, honest and transparent communication from TVA to tell the public exactly what’s going on and what happened so we can learn from it and do better in the future.”
TVA said it was generating about 23 GW on midday Friday, about 7 GW short of what was needed.
With insufficient generation and not enough imports from neighboring grids, TVA ordered rolling blackouts from its local power companies like the Nashville Electric Service, which voluntarily cut power to customers in intermittent intervals.
NES rotated blackouts between 320,000 customers in total, with 72,000 people affected at peak. NES has not provided data on who lost or maintained power but said it targeted feeder circuits that weren’t connected to critical facilities like hospitals.
Before the rotating outages, NES said that between 2,000 and 4,000 customers were without power “due to typical storm-related issues.”
The Arctic has warmed nearly four times faster than the rest of the planet in recent decades, much faster than previously thought, a recent study found. This rapid climate change has been stretching the Arctic polar vortex, which is the band of strong winds normally lassoed around the North Pole and the northernmost polar air. When weakened, the polar vortex can dip south and push frigid air over Canada, the U.S. and parts of Asia.
This phenomenon is projected to make severe winter weather like this most recent event more common, according to a study in Science that reviewed data from 1980 to 2021.
TVA did not respond to a question from WPLN News about how climate change and the projected increases in winter storms would affect their current power plans.
TVA is building more gas plants
To manage winter demand, TVA has opted to build more gas plants, like the heavily-contested 1.5 GW plant near Clarksville, the planned plant for Kingston, and the approved Humphreys County facility, which the Southern Environmental Law Center alleged did not have its climate impacts fully considered by TVA in a lawsuit this week.
This strategy proved to be problematic this past weekend for TVA, which was not the only utility impacted. The reliability of natural gas during winter storms has been questioned more closely since the events of the February 2021 storm in Texas. A recent report found that natural gas and coal capacity in the U.S. may be overestimated by more than 20%.
In other words, adding more fossil fuels to the grid won’t prevent blackouts.