The Tennessee Valley Authority avoided blackouts during this week’s Arctic freeze partially thanks to people around Tennessee voluntarily reducing their energy consumption.
On Tuesday afternoon, TVA asked people to turn down their thermostats and reduce their energy use on Wednesday morning, the expected peak of the freeze event.
Shortly after, demand flattened.
At 10 p.m. Tuesday night, total electricity demand was about 10 percent, or 3.4 gigawatts, lower than TVA forecasted. Electricity peaked at 8 a.m. on Wednesday, setting a new record of more than 34 gigawatts — and about 1.7 gigawatts lower than expected, according to the data TVA reported to the U.S. Energy Information Administration.
“I think we learned from this event that even a voluntary call for conservation made a big difference,” said Daniel Tait, a researcher at the Energy and Policy Institute. “If customers are willing to do this out of their own goodness for the system, then think about what kind of opportunity we could have if customers were actually being compensated to do this.”
Courtesy Tennessee Valley Authority The Tennessee Valley Authority faced lower demands than projected during a cold snap in January 2024.
The idea of paying customers to reduce energy use is called demand response. Energy advocates have long been calling on TVA to implement demand response programs to help create a more flexible grid and lower costs to customers, since reducing demand is cheaper than building new power plants.
TVA suggested the voluntary conservation call was effective.
“We do believe the public’s assistance in conserving energy helped reduce demand this week,” TVA spokesperson Adam May said in an email.
Note: Temperatures will get down to single digits again Saturday night, so it may be a good idea to keep up the voluntary efforts.
TVA used imported energy
While blackouts did not happen this time, the threat was real. TVA and systems it relies on haven’t fixed all of the issues that led to hundreds of thousands of Tennesseans losing power during rolling blackouts last winter.
TVA largely kept the lights on this week with imported energy, experts say. During the peak, TVA was importing about 5.6 GW of energy from other systems — equivalent to about 16% of the total energy needs.
There could be two reasons for this.
“It might have been that it was just cheaper to buy from a neighbor than to turn on some of their more expensive plants that they own or have contracts with,” Tait said. “Or it could have been that some of the plants that they wanted to use of their own didn’t perform as expected.”
Courtesy Tennessee Valley Authority The Tennessee Valley Authority used less total gas generation during peak on January 17, 2024, than during Winter Storm Elliott in December 2022, when the utility instituted rolling blackouts.
If the cold snap affected a wider swath of the country, like what happened during Winter Storm Elliott in December 2022, there may have been fewer imports available.
TVA said its staff would be analyzing the event in the coming weeks.
TVA used less gas this year
Last winter, the day before Christmas Eve, TVA lost a fifth of its power. The methane gas system, including the plants, pipelines, drilling sites and compressor stations, failed and several coal plants faltered, investigations later revealed. This translated to rolling blackouts and hundreds of thousands of Tennesseans losing power.
Methane gas, a fossil fuel better known as natural gas, is the largest source of electricity in the U.S. It has also been the cause of an outsized portion of blackouts. During the freeze last winter, 10 of TVA’s 17 gas plants had issues.
“You’re hearing TVA talk about gas as a reliability need and sort of as the ‘bridge to renewables,’ but if the bridge is offline when we need it most, it’s not a very effective bridge,” said Brady Watson, a senior campaign coordinator at the Union of Concerned Scientists, a science advocacy nonprofit.
Courtesy Union of Concerned Scientists A report by the Union of Concerned Scientists found that an overreliance on methane gas as an electricity source is a threat to grid reliability.
More: Tennessee is vulnerable to winter blackouts. Here is a big reason why. | WPLN News
During the cold snap in December 2022, TVA generated up to 11.5 GW of gas. TVA has added about 1.4 GW of gas capacity since then and plans to add another 5 GW of gas in the next few years.
This year, TVA’s gas generation maxed at 10.6 GW on Wednesday.
How to safeguard the grid
There are many ways to make the grid more resilient to cold snaps, heat waves and extreme weather in a warming world. Watson said TVA’s claim of building more fossil fuel plants for reliability was “ironic” given that their continued use will worsen many types of extreme weather in the future.
“There are better options out there that are better for the climate and better for reliability,” Watson said.
On a large scale, TVA could plan transmission lines with other regions in the nation to access power further away, such as wind power in the west.
At the city level, TVA could allow local power companies, like the Nashville Electric Service, to produce more of their own power. TVA has contracts with nearly all of its local power companies that limit them to generating just 5% of their energy needs — and TVA asked them to cut 10% of their power during Winter Storm Elliott.
“It puts the local power companies between a rock and a hard place with respect to providing reliable power to their customers in times of emergency,” said Jim Rossi, an energy law professor at Vanderbilt University. “They are almost 100% dependent on a monopolist that is TVA for their source of energy.”
At a smaller scale, TVA could focus more on energy efficiency, the cheapest way to reduce energy use. Efficiency is a broad term that includes things like heat pumps and modern windows in homes.
Small, scattered efforts can add up, according to Eric Larson, an energy scientist at Princeton University. He’s been overseeing research to determine how much rooftop solar panels, which cover just 0.16% of homes in the Nashville area, could reduce demand from utilities.
“If you were to actually be able to put more solar on rooftops, the amount of generation is pretty significant,” Larson said.
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