Photographs by Morgan Hornsby

On November 10 of last year, at a place called Paradise in western Kentucky, the Tennessee Valley Authority blew up the cooling towers of a large coal-fired power plant. The three stout towers, each 435 feet high, buckled at the waist in synchrony, then crumpled like crushed soda cans. Within 10 seconds, they’d collapsed into a billowing cloud of dust.

To anyone who watched the demolition happen, or saw the footage online, the message was clear: TVA, a sprawling, federally owned utility created 90 years ago as part of President Franklin D. Roosevelt’s New Deal, is getting off coal.

Though some people in the region regret that move, it’s a win for the local environment—and for the global climate. In the past few years, as the urgency of slowing climate change has grown, something like a consensus has emerged on how to do it: Green the electrical grid while retooling as much of the economy as possible—cars, buildings, factories—to run on zero-carbon electricity. The Inflation Reduction Act, signed by President Joe Biden last August, is supporting that plan with $370 billion in subsidies. In a 2021 executive order, Biden directed the federal government to “lead by example in order to achieve a carbon pollution–free electricity sector by 2035” and a net-zero economy by 2050.

Given this strategy, electric utilities are crucial to our future—and none more so than TVA, the largest public power provider in the United States. Its territory covers nearly all of Tennessee; large chunks of Alabama, Mississippi, and Kentucky; and bits of three other states. In one of the most conservative regions of the country, 10 million people get electricity from a federal agency that has no shareholders to answer to and no profits to make.

“TVA is this crazy unicorn—it’s not like anything else,” Stephen Smith, the executive director of the Southern Alliance for Clean Energy, told me. As a federal agency responsible not just for promoting the clean-energy transition but for building it, TVA is positioned to provide a national model—and TVA says it is doing just that.

But that’s not how Smith and other environmental advocates describe TVA’s behavior. They see a utility that is replacing coal plants, at Paradise and elsewhere, with gas-burning plants that will pollute the climate for decades. They see a utility betting heavily on small nuclear reactors that don’t yet exist. Above all, they say, TVA is failing to embrace proven clean-energy technologies, such as solar and wind power and energy-efficiency measures.

“TVA is a living laboratory that could be part of a phenomenal push to change to clean energy,” Smith said. Instead of an agency “on a war footing to get us to zero carbon,” he sees it becoming “an impediment in the executive branch.”

TVA has cut its carbon emissions by well over half since 2005, far more than the nationwide average for the electricity sector, while charging lower-than-average rates. It has done so by replacing coal with gas and by switching on a large new nuclear reactor. But like most American utilities, TVA has no plans to reach Biden’s goal of a net-zero grid by 2035; it’s targeting only an 80 percent carbon reduction by that date. “We aspire to net-zero by 2050, and we aspire to go farther, faster, if we can,” Jeff Lyash, TVA’s president and CEO since 2019, said at a meeting of the agency’s board of directors in November. With existing technology, though, he doesn’t think that’s possible.

What’s the right road to net-zero? The Tennessee Valley is an illuminating microcosm of a national debate, in which the imperative of addressing climate change is pitted against the enormous practical challenge of not only maintaining a reliable electric supply but dramatically expanding it to meet the needs of a decarbonizing economy. “TVA is in a unique position to lead in delivering the clean-energy future,” Lyash said in November. He and his critics agree on that much. But as for when that future will arrive, and what it will look like, they are very far apart indeed.  

T

VA was born from another global crisis. In 1933, when Roosevelt and Senator George Norris, a Nebraska Republican, persuaded Congress to establish TVA, the United States was at the nadir of the Great Depression, and the Tennessee Valley, where only a tiny percentage of the homes had electricity, was one of the country’s poorest regions. TVA transformed it. Starting with the Wilson Dam, at Muscle Shoals, Alabama, a series of dams controlled flooding on the Tennessee River and its tributaries and electrified the whole Valley. Hydroelectric plants still produce about 10 percent of the region’s power, carbon-free.

Private utilities hated TVA, and complained bitterly about what they saw as unfair competition. They challenged the agency’s existence before the Supreme Court and lost, twice. As late as the 1950s, President Dwight Eisenhower wanted to sell off the agency, which he saw as an example of “creeping socialism.” The agency survived by becoming quasi-independent of the federal government. The president appoints and Congress confirms TVA’s board, but since 1959, TVA has mostly done without federal appropriations. It pays its own way by selling electricity—not directly to consumers (aside from a few dozen industrial and federal properties), but to the 153 municipally or cooperatively owned local power companies, or LPCs, that distribute power to the people.

Top left: Widows Creek Steam Plant, 1961. Top Right: Wilson Dam, June 1942. Bottom: TVA directors with President John F. Kennedy in 1963. (Courtesy of National Archives Catalog)

From the start, TVA’s strategy was to make electricity cheap and accessible enough that people would use it for everything. The agency succeeded so well that demand soon outstripped what even a thoroughly dammed river could supply. In the ’50s, TVA began relying on coal as its main energy source, ultimately building 12 large power plants. Over the past decade, it has closed six, but giant piles of toxic ash remain. In 2008, a dike ruptured at the coal plant in Kingston, Tennessee, spilling more than 5 million cubic yards of ash into the Emory and Clinch Rivers.

Environmentalists have long had reason to distrust TVA. In the ’70s, when the newly created Environmental Protection Agency began regulating air pollution, TVA resisted. Accustomed to making its own engineering decisions, it argued that investing in scrubbers for its coal stacks made no sense—after all, it was about to replace most of them with nuclear reactors. But the agency completed only seven of a planned 17 reactors—demand for electricity grew slower than forecast—and today, unfinished reactor hulks lie scattered around the Valley. The fiasco left TVA constrained by debt, which still totals nearly $20 billion.

[From the April 1962 issue: Harry Caudill on TVA and the destruction of the Appalachian Mountains]

Nevertheless, TVA is proud of its nuclear fleet. Although Georgia Power is expected to bring a new reactor online soon, TVA has been the only U.S. utility to have managed that in the past three decades. It began construction on the two reactors at its Watts Bar plant, in Tennessee, in 1973; mothballed them for years; then completed them in 1996 and 2016. In the first half of 2023, they and the agency’s other reactors helped it generate nearly 60 percent of its kilowatt-hours without emitting carbon—significantly higher than the national average. But it has “fumbled, failed, and flopped” into that enviable position, Stephen Smith told me. The climate crisis demands transformative change, Smith said, and TVA has abandoned its historic mission to provide precisely that.

TVA’s Colbert gas plant, which is under construction, in Florence, Alabama, July 7, 2023 (Morgan Hornsby for The Atlantic)

In downtown Chattanooga, the people directly responsible for delivering electricity to the Valley’s 10 million residents sit in TVA’s system-operations center. It’s a large, hushed, dimly lit room, in which curving rows of workstations face a wall filled with an illuminated schematic of TVA’s sprawling transmission grid. The first rows of operators track the physical condition and voltage of the transmission lines. The operators behind them “dispatch” power as needed from hundreds of generators around the grid, matching supply to demand minute by minute. That complex job is simplified by having lots of “dispatchable” power, which is what coal, gas, nuclear, and hydro plants provide, at least in principle: power that’s available any time of the day or year.

In a conference room overlooking the control room, I met Greg Henrich and Aaron Melda, TVA’s vice president and senior vice president for transmission and power supply. Melda had helped formulate the agency’s decarbonization strategy, and he grabbed a marker to sketch out the numbers on a flip chart. The strategy’s central element is the closure of TVA’s last five coal plants, all more than 50 years old, by 2035. “Over the same period, we will add 10,000 megawatts of solar,” Melda said. To store energy for when the sun isn’t shining, TVA will also add 1,000 megawatts of battery capacity.

Over the next decade, though, the agency’s main carbon-reduction strategy is to build more gas plants—7,000 megawatts’ worth, roughly the capacity of the current coal fleet. When I visited the system-ops center last fall, TVA was finalizing plans for the latest addition: a 1,450-megawatt gas plant in Cumberland City, Tennessee, at the site of its biggest coal plant, whose two generating units are scheduled to retire in 2026 and 2028. Environmentalists strenuously opposed the gas plant—even the EPA questioned it—arguing that it would commit TVA to emitting carbon long past 2035 or even 2050. In the near term, though, the switch from coal will substantially reduce emissions of carbon and other pollutants. “You replace coal with gas, you’ve now taken every one of those megawatts down 50 percent in its carbon intensity,” Melda said.

Why not just build more batteries and more solar, and take the intensity down to zero? It would cost a lot more, Melda said, and batteries discharge within several hours. A few rainy days could leave you unable to meet demand. Nor is solar a big help on dark winter mornings, which are the moments that TVA worries about most. The majority of homes in the Valley have electric heat. A spokesperson for TVA, Scott Fiedler, later said that gas is “the only mature technology that allows us to quickly add renewable energy and maintain the low cost and reliability” needed.

I visited the system-ops center on a chilly November day a week before Thanksgiving. Early that morning, as people cranked up their thermostat, TVA had seen a fairly typical winter peak in the load on its grid. Warmer weather was coming that would drive down demand, Henrich said, but it would rise again on Thanksgiving morning, as people roasted turkeys. That afternoon, the load would plummet. “Everybody’s asleep on the couch,” Henrich said. “It’s awesome to watch—it’s truly societal behavior driving your load.”

He opened the blinds on the conference-room windows so we could see into the control room itself. It looked pretty quiet, with a lot of the workstations empty. “When does it ever get exciting?” I asked. A month later, my question was answered.

Aaron Melda (left) and Greg Henrich, TVA’s vice president and senior vice president for transmission and power supply, at TVA’s main headquarters, in Chattanooga, July 6, 2023 (Morgan Hornsby for The Atlantic)

On December 23, people in the Tennessee Valley awoke to temperatures that had plunged 40 degrees or more overnight. Worse, both units of the Cumberland coal plant had shut down, because thick ice from a big storm had encased instruments on the exposed boilers. In the morning, the Bull Run coal plant wouldn’t start, and some natural-gas plants failed too. As demand soared to an all-time winter record of 33,427 megawatts, the operators in Chattanooga found themselves about 8,000 megawatts short. Neighboring utilities couldn’t help; the storm had affected half the country.

For two hours that morning, TVA had to instruct its 153 local power companies to cut demand by 5 percent. On Christmas Eve, it asked for a 10 percent cut for more than five hours. To comply, the LPCs shut off power neighborhood by neighborhood for 15 minutes or more at a time. The rolling blackouts were the first in TVA’s 90-year history. At Christmas dinner, Fiedler told me, his mother required him to explain why his storied organization had cut her power on the holiday. “She wore me out,” he said.

TVA likes to boast of its reliability, and environmental advocates seized on the Christmas failure. “The emperor has no clothes,” Amanda Garcia, the director of the Southern Environmental Law Center’s Tennessee office, told me. “The winter storm to me provided a perfect example of why TVA needs to change”—by showing that fossil fuels are no guarantee of reliability and that it should be transitioning to renewables faster. The Sierra Club ranks TVA among the very worst American utilities for its energy transition. The Center for Biological Diversity calls it a “climate laggard.” Both want the agency to replace all its coal plants as soon as possible with renewable energy, not gas.

A modeling study released in March by the Center for Biological Diversity and by GridLab, a nonprofit consulting group, concluded that TVA could indeed stop burning both coal and gas by 2035. To do that, it would need to build the equivalent of about 145 large solar farms, with a total capacity of 35 gigawatts, in its territory, along with the transmission lines needed to import about 12 gigawatts of wind power from the Midwest. (The Valley isn’t windy enough to produce cost-effective wind power.) Then, by 2050, it would have to nearly triple that expansion again in order to electrify and decarbonize the Valley’s economy. The goals are ambitious, given the delays that now plague many renewable and transmission projects—but the benefits to society would dwarf the costs, the study found. Consumers would save more than $250 billion, mostly from switching to cars that run on TVA’s electricity rather than gasoline. Carbon emissions would drop by hundreds of millions of tons.

The first step toward a clean-energy future, advocates agree, would be to reduce energy waste in the Valley. About a quarter of homes there rely on resistance heating—the method employed in electric furnaces and space heaters. Many heat pumps also fall back on it at freezing temperatures, Huntsville Utilities’ president and CEO, Wes Kelley, told me. “That is basically the equivalent of turning on a bunch of big hair dryers to heat your house,” Kelley said.

According to National Renewable Energy Laboratory estimates, efficiency measures, including more and better heat pumps, could save roughly as much electricity as the Cumberland gas plant will generate. “If you reduce that resistance heating, you’re helping the system as a whole”—by reducing the peak load—“as well as the customer,” Maggie Shober, the research director at the Southern Alliance for Clean Energy (SACE), told me. Because people in the Valley use so much electricity, monthly bills are high even though rates are low, creating an especially heavy burden on the poor.

Utilities generally have little incentive to invest in energy-saving measures, which only reduce their revenue. But TVA should be different: It doesn’t need to make a profit. Since 2018, it has run an admirable program, called Home Uplift, that provides heat pumps, weatherization, and other measures to low-income homeowners, all for free—but so far, only to 5,000 of the hundreds of thousands of Valley residents who might be eligible. TVA could do much more, SACE and other critics say, especially now that the Inflation Reduction Act is subsidizing energy-efficiency programs. For its part, TVA says it’s planning more of these types of investments, including rebates to replace older and less efficient heat pumps. Fiedler, the TVA spokesperson, said the agency will lower energy costs in underserved communities by $200 million over the next five years through Home Uplift and other programs.

TVA’s Wilson Dam, in Muscle Shoals, Alabama, July 7, 2023 (Morgan Hornsby for The Atlantic)

The environmental advocates I talked with were all suspicious of TVA’s clean-energy intentions. SACE’s Stephen Smith, a close observer of the agency for more than three decades, thinks TVA is building gas plants now and planning nuclear for the future because large power plants are what it is comfortable building, and it has a monopoly on building them in the Valley. The future of the industry should lie in “shifting from central stations to a more distributed model that opens up a whole new powerful toolbox for fixing the climate crisis,” Smith said. “But TVA is not going there.”

He and other advocates see a “rapidly closing window of opportunity to secure a liveable and sustainable future,” to quote the most recent United Nations climate report, and in that stark light, TVA’s current fleet of renewables looks inadequate, especially if you set aside the hydroelectric dams and focus on what it has achieved lately. It buys about 1,200 megawatts of wind from the Midwest; it has installed about 1,000 megawatts of solar capacity in the Valley. That’s far less solar power, Amanda Garcia pointed out, than deployed by utilities in the Carolinas or Georgia. Though she acknowledged TVA’s plans to expand solar over the coming decade, “actions speak louder than words,” she said.

But TVA is actually making a big effort these days, Gil Hough, the executive director of TenneSEIA, the state solar-industry association, told me. Hough worked for SACE from 2000 to 2010, promoting solar with Smith. Now he helps deliver it to TVA.

In the mid-2010s, he told me, the agency did indeed walk away from solar because it was focused on paying down its nuclear debt. Under Lyash, though, TVA has changed, Hough said. It may have only 1,000 megawatts of solar online—but it has more than 2,200 under construction or contracted. “TVA wants every megawatt we can provide them right now,” Hough said. “It’s us who’s holding them back.” Supply-chain disruptions have slowed solar projects and raised prices. But Lyash announced in May that TVA would award contracts this year for 6,000 megawatts of solar power, to be brought online between 2026 and 2029. “We are building as much solar as we can get panels for,” he said.

What got TVA’s attention was the demand from large corporations, says Reagan Farr, the CEO of the Nashville-based Silicon Ranch, which owns and operates solar farms for TVA and other utilities. Farr told me that companies like Google and Meta, by insisting on renewable energy, convinced TVA that it could no longer fulfill its mission of economic development without expanding its solar capacity. “The power of these large companies—their procurement decisions drive actions,” Farr said.

Local resistance to solar farms is a growing problem, both TVA and the industry say. At the November TVA board meeting, Chief Operating Officer Don Moul announced a $216 million plan to build a 100-megawatt solar plant on top of the coal-ash pile at the Shawnee power plant, in Kentucky. If it works, Moul said, as much as 1,000 megawatts of solar might one day rise from ash piles around the region—poetic justice, and a way to “alleviate some of the land challenges that we’ve heard about from so many of our stakeholders,” Moul said.

One of TVA’s key constituencies are the local power companies that distribute its electricity. Their perspective is often very different from that of environmental advocates. At a listening session before a February 2023 board meeting in Muscle Shoals, a dozen of their representatives got up to speak—not about renewables or climate change, but about the blackouts. They were a “black eye for all of us in the Valley,” said Brian Solsbee, the executive director of the Tennessee Municipal Electric Power Association and a former TVA employee. “How does TVA ensure it never happens again?” It needs new generation capacity, Huntsville Utilities’ Wes Kelley told me.

When it was Lyash’s turn to speak, he said what he has said repeatedly: that TVA plans to use all available technologies to decarbonize. He promised a renewed focus on energy efficiency and an aggressive expansion of solar—but also of gas and, in the long run, nuclear. “Don’t put all your eggs in one basket,” he said. Renewables, in his view, are one basket.

TVA’s Watts Bar Nuclear Plant, in Rhea County, Tennessee, June 30, 2023 (Morgan Hornsby for The Atlantic)

The Tennessee Valley is going through a period of economic expansion that would make Roosevelt proud, and TVA, with its reputation for cheap and reliable power, is partly responsible. The Valley’s new growth includes electric-vehicle, battery, and solar-panel manufacturers—the industries that will drive the electrification of America. When I first met Lyash in Chattanooga, where he had just presented TVA’s Engineer of the Year award, he rattled off some of the names. “Ford, GM, Toyota, Mazda, Volkswagen, LG, SK—those industries are going to decarbonize transportation,” he said. “So we have to provide them the energy now.” Demand is growing already, and Lyash expects it potentially to double by 2050. A study last year by the National Renewable Energy Laboratory (NREL), which mapped how the grid might be decarbonized by 2035, in line with Biden’s goal, assumed that demand might even double by then.

The decision to build a new gas plant at Cumberland comes in that context as well as that of climate urgency. In TVA’s view, even if it could build enough additional renewables and transmission lines to replace the Cumberland coal unit it plans to retire by 2026, which it says it can’t, solar and wind wouldn’t offer “firm, dispatchable power”—power that’s available regardless of weather or time of day. The basic problem, as the NREL report explains, is “seasonal mismatch”: There’s not enough sunlight to meet peak demand on cold winter mornings and not enough wind on hot summer afternoons; both can be minimal for days.

Given this reality, is it reasonable to build a new gas plant today, even though it will emit some carbon for years to come? I put the question to Paul Denholm, a senior research fellow at NREL and the lead author of the recent study. “That is a fantastic question, and it’s something everybody is trying to figure out,” he said.

All visions of a decarbonized grid and of an electrified, net-zero society require huge expansions of wind and solar power. But the NREL study foresees that a net-zero grid will also need some kind of gas to meet peak demand. In three of its four net-zero scenarios, turbines are still burning substantial amounts of natural gas in 2035, and the carbon is being captured rather than released into the atmosphere. In all scenarios, many gas turbines are retrofitted to burn zero-carbon hydrogen.

TVA’s vision of the future, as Lyash and Aaron Melda explained it to me, aligns broadly with the NREL study. Any gas plants that TVA builds now, they said, will one day either burn “green hydrogen” or involve carbon capture—neither is in wide use yet, and TVA is investing in both. The reason TVA won’t promise a net-zero grid by 2035, Lyash said, is because “it’s going to take deploying technologies that are not currently available at a price people can afford and a scale that can be implemented.” The NREL study assumes that those technologies will be developed in time to reach net zero by 2035; TVA doesn’t want to count on that.

It’s no surprise, Denholm said, that utilities are struggling to figure out how to cut the last 10 to 20 percent of their carbon emissions. NREL researchers haven’t figured it out either. “The fact that you have conservative utilities saying they know how to [cut] 80 percent—that is a really remarkable shift,” he told me. “I think we need to recognize that and applaud it.”

Another influential report, Princeton’s 2021 “Net-Zero America” study, included a scenario in which only renewable energy was allowed: By 2050, wind turbines were visible from about one-eighth of the area of the Lower 48 states, solar farms covered an area the size of West Virginia, and long-distance transmission lines mushroomed to five times their existing capacity. Even when such facilities share land with other uses—Silicon Ranch, for instance, allows sheep to graze or pollinator gardens to bloom among the solar panels—they are a significant industrial intrusion on the landscape.

In some regions, people may prefer less of those—and more of the compact central power stations that TVA knows how to build. The NREL and Princeton studies both include net-zero scenarios in which the expansion of renewable facilities and transmission lines is constrained, perhaps by “challenges with siting and land use,” as NREL puts it. Both scenarios rely, as does TVA, on nuclear plants. “I can’t make the numbers work without new nuclear,” Lyash told me.

Like many nuclear engineers these days, he thinks the future lies in small modular reactors, or SMRs. At a site on the Clinch River, TVA is planning the first of what it hopes will be a fleet of 20 or so identical SMRs, using a relatively conventional design. “Our goal is not just to build a plant, but to build a plant that sets the model for the U.S. industry,” Greg Boerschig, one of the engineers running the TVA effort, told me.

The way environmentalists focus on TVA’s renewable capacity or lack thereof frustrates Lyash. “The point is,” he said, “what are your carbon emissions, and what’s your price, and what’s your reliability?” Different regions with different starting points—Arizona has a lot of sunshine, Oklahoma has wind, TVA has a legacy of nuclear and hydro—might reach their clean-energy goals in different ways.

Toward the end of our last conversation, Lyash opened an app on his phone that shows real-time carbon emissions from electricity generation. “One of the countries that gets held up as having deployed huge amounts of solar, and it’s a big percentage of their capacity, is Germany,” he said. “Germany’s carbon emissions right now are 426 grams per unit of electricity. And today, right now, TVA’s is 247 … And our price is less than a third of theirs.”

That happened to be a bad day for Germany’s numbers and a good one for TVA’s—but long-term data confirm Lyash’s point: Germany gets a far higher percentage of its electricity from renewables than TVA, but emits substantially more carbon per kilowatt-hour. Germany has made different choices. It closed its last nuclear reactor in April.

TVA’s Norris Dam, in Andersonville, Tennessee, June 30, 2023 (Morgan Hornsby for The Atlantic)

Environmentalists are right to be wary of TVA. In the past it has performed badly on a variety of environmental issues. It built an unnecessary dam, the Tellico, that drowned important Cherokee cultural sites and hundreds of farms and notoriously threatened to extinguish a little fish, the snail darter. (The darter has since recovered.) It stepped back from solar and energy-efficiency efforts when it could have led the way. It was slow to reduce air pollution from its coal plants—which are still lethal polluters—and allowed the major coal-ash disaster in Kingston to happen. This May, even as Lyash was promising 6,000 megawatts of new renewable energy, TVA doubled down on its Cumberland decision: It released a draft environmental-impact statement saying that it also wanted to replace the Kingston plant with gas power by the end of 2027. That will lock in higher emissions for longer, environmentalists say.

Garcia and Smith think TVA lacks public accountability. They point out that it has no independent public-service commission to regulate it, only a board that, like corporate boards, has no staff of its own and thus depends on management. They would like to loosen TVA’s monopoly and free local power companies to buy power elsewhere, bridling the “unicorn” with market discipline.

But that would risk undermining the very thing that makes the agency such a precious unicorn: the public-power model. TVA has retained political support, at least in its sphere, for an active government role in improving people’s lives. And in a region where environmental causes are hardly unifying, TVA has said, publicly and repeatedly, that it wants to stop emitting carbon as fast as it can. How it does that should be debated—but in many conversations with TVA and its critics, I never heard a solid reason to doubt its good faith.

As I traveled the Tennessee Valley, I visited monuments from TVA’s golden age, including Wilson Dam, in northwestern Alabama, with its lofty, sunlit turbine hall and arches like a Roman aqueduct’s, and Norris Dam, in northeastern Tennessee, which closes off the narrow Clinch River with a tall, sculptural curve. TVA engineers and the people of this region built these marvels “for generations yet unborn,” as Senator George Norris liked to say,  with no notion of how valuable they would become in an age of climate change.

Now it’s time to build more.

This article is part of the Atlantic Planet series supported by the HHMI Department of Science Education.