TVA moves forward with natural gas and new pipeline to replace Kingston coal plant by 2027

Tennessee Valley Authority staff solidified plans to close the massive Kingston Fossil Plant by 2027 and replace its coal generators with a natural gas plant, some solar panels and battery storage.

The recommendation came in a final environmental impact statement, which was issued Feb. 16 after TVA fielded more than 600 comments during a public review process last year. The statement said it would cost $2.2 million to prepare the aging coal-fired plant for its long-awaited retirement.

The plant was the site of one of the most catastrophic industrial disasters in U.S. history when more than 1 billion gallons of coal ash spilled over the Kingston community and into the Clinch River on Dec. 22, 2008. Last year, TVA's coal ash cleanup contractor Jacobs Solutions reached a settlement with cleanup workers and their families who alleged the firm was responsible for multiple deaths and illnesses for not protecting them from the dangerous waste. The terms of the settlement are confidential.

Years before it took public comments on what should replace the Kingston plant, TVA entered into a partnership with Enbridge to build a new natural gas pipeline that could feed the plant's replacement.

TVA plans to retire its four remaining coal plants — Cumberland, Gallatin, Kingston and Shawnee — by 2035 and wants to reach net-zero carbon emissions across its system by 2050. Its coal plants are among the oldest in the nation and are facing performance issues.

The statement was a recommendation from staff for the future of the plant, once the largest coal plant in the world, and not a final decision.

As TVA leans on carbon-free energy sources for over half of its electricity, it uses coal plants largely on an as-needed basis to meet high demands, like during extreme weather. But all that turning off and on is a strain on the aging plants.

The TVA statement said the utility turns the Kingston plant off and on an average of more than 85 times a year, which exceeds the plant's design and has accelerated its deterioration.

Completed in 1955 to produce electricity for Oak Ridge during the Korean War, the Kingston Fossil Plant still burns 14,000 tons of coal a day to generate close to 1,400 megawatts of electricity, enough to power more than 800,000 homes. The plant is notable for its twin 1,000-foot chimneys, which tower over Interstate 40.

TVA has changed the way it stores coal ash and has closed seven coal plants since the spill, opting to replace coal generation largely with natural gas, another fossil fuel with lower carbon emissions. TVA has built several new gas plants, including the John Sevier plant in Rogersville, on the site of retired coal plants.

"A diverse generation portfolio – that includes nuclear, gas, coal and renewables – enables TVA to better meet changing market conditions, including the load growth our region is seeing," an agency spokesperson said in a statement.

Since 2005, TVA has cut its carbon emissions by about 60%, thanks to a combination of closing coal plants, opening a new nuclear generation unit at Watts Bar in 2016, and investing in renewable energy like wind and solar.

The environmental impact statement said TVA would need to build at least 1,500 megawatts of replacement generation ready to go at any hour to serve East Tennessee residents and avoid straining the high-output Watts Bar and Sequoyah nuclear plants, which are critical to the agency's clean energy capabilities.

Here's how TVA might build that replacement generation.

What will TVA do with the Kingston site?

TVA explored two options for replacing electricity production at the Kingston Fossil Plant, but its staff prefers the option that includes building a natural gas facility on the site. Either way, TVA plans to demolish the plant after it is retired in 2027.

Like at its Colbert and John Sevier plants, TVA would not build the new gas plant directly in the footprint of the closed coal plant.

TVA also evaluated what would happen if it kept the Kingston plant running, which the report said would cost $655 million in upgrades beyond the plant's routine operations. If TVA tried to convert Kingston's coal generators to gas, the agency said the gas plant would be less efficient and cost effective than a new gas plant.

Beyond a new gas plant, TVA's preferred option also would include a 35-acre, three- or four-megawatt solar site and a 100-megawatt battery storage system at the Kingston site. The report said three to four megawatts of solar is all that would fit at the Kingston site if a gas plant were built there.

In order to supply natural gas for a new Kingston plant, TVA is working with pipeline operator Enbridge to build a 122-mile natural gas pipeline across eight Middle and East Tennessee counties. The Ridgeline Expansion Project is subject to approval by the Federal Energy Regulatory Commission.

If all permitting goes through, Enbridge plans to begin construction of the pipeline in 2025 and complete it in fall 2026. The pipeline route would closely follow an existing East Tennessee Natural Gas pipeline to minimize impacts to landowners and the environment, though climate advocacy groups have criticized the plans.

“Rural Tennesseans have long borne the burden for powering our state with dirty and expensive fossil fuels, and this project continues that legacy,” said Emily Sherwood, a field organizer for the Sierra Club, in a release. “As the largest public utility in the nation, it’s time for TVA to shift their energy generation to clean and safe energy sources that center the needs of the communities they are charged to serve.”

The second and less likely route TVA could take to replace Kingston's coal power is to build multiple solar and battery storage systems across its system, including in East Tennessee, which would have lower carbon emissions but require more transmission upgrades.

TVA staff said in the report that they do not prefer this cleaner option because solar is less reliable and would take longer to become operational than a gas plant. TVA sees its highest energy demand in the late afternoon during the summer and in the early morning in the winter, two times when solar energy cannot reliably put electricity on the grid.

Though solar and battery storage are relatively cheap sources of energy, an additional 1,500 megawatts of solar and 2,200 megawatts of battery storage would require 10,950 acres of land, the TVA report said. The added solar would be in addition to TVA's overall goal of adding 10,000 megawatts of solar by 2035.

In its last long-term plan, released in 2019, TVA set goals to add up to 18,400 megawatts of new natural gas generation – split between combustion turbine and combined cycle plants – and up to 14,000 megawatts of solar capacity by 2038. The agency will update its long-term plan this year.

Daniel Dassow is a growth and development reporter focused on technology and energy. Phone 423-637-0878. Email daniel.dassow@knoxnews.com.

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This article originally appeared on Knoxville News Sentinel: TVA pushes to replace Kingston coal plant with natural gas by 2027