September 22, 2026 - The Tennessee Valley Authority's decision to abandon the retirement of two coal-fired power plants could cost the nation's largest public utility more than $1 billion over several years, but a final price has not been calculated for the reversal.

TVA, which supplies electricity across seven states, is assessing the work required to keep the Tennessee coal plants operating before determining how much it will need to invest, TVA spokesperson Scott Brooks told Knox News. The utility is required under its federal mandate to pursue the lowest-cost options for serving ratepayers, making the economics of its power plants a central factor in decisions about the utility's mix of various energy sources such as coal, natural gas, nuclear and hydroelectric.

The utility's total energy load has been higher in 2026 than TVA expected when it announced plans in 2021 to retire the coal units at its Cumberland Fossil Plant in Stewart County and its Kingston Fossil Plant in Roane County by 2035.

TVA staff said generating capacity as of January 2026 was "below TVA's firm requirement through 2031," according to an analysis of the Cumberland plant. The analysis found that keeping the Cumberland plant online could reduce TVA's total system costs by nearly $1.8 billion, but those gains are "partially offset by the investment required for (Cumberland's) continued operation and system-wide production (dispatch) costs."

TVA's analysis reached a different conclusion for Kingston. Staff found that continuing to operate the plant would result in roughly the same overall system costs as retiring it.

TVA estimated in early 2026 that keeping the Cumberland plant's coal units online would require a $738 million investment, according to documents prepared as the utility planned for the plant's retirement. TVA analyses also projected a $636 million investment to keep the Kingston plant operating, bringing the combined cost to about $1.37 billion.

Brooks, in an email to Knox News, said some assumptions have changed since the documents were prepared. The analyses were "based on known conditions and some educated assumptions based on the performance of the units at the time," as well as "some long-term strategies that we did not intend to perform based on the planned closures."

Like many power providers that still rely on coal, TVA operates an aging system of coal-fired plants. Kingston's coal units began operating in the 1950s and the Cumberland units plugged into the grid in 1973.

Federal energy landscape shifts amid TVA plans

In its first meeting of 2026, TVA's governing board voted to reverse plans to retire the Cumberland and Kingston coal units. The vote came after President Donald Trump, a consistent booster of the coal industry, spent 2025 reshaping the board by removing directors appointed by former President Joe Biden and replacing them with his own picks.

TVA said the decision was driven by power demand, which has exceeded expectations in recent years and is projected to keep growing, according to TVA staff. Data centers and a growing residential population have forced the utility to reassess how much generating capacity it will need in the years ahead.

Coal ash cleanup worker Brian Thacker stands at the Swan Pond Sports Complex with the TVA Kingston Fossil Plant in the background on Dec. 22, 2018, the 10th anniversary of the Kingston coal ash spill. TVA is now evaluating the cost of extending the life of the aging coal-fired facility after reversing plans to retire its coal units.

President Trump has sought to keep coal plants operating longer than planned, though federal judges have blocked some of those efforts. TVA's decision to extend the life of its Tennessee coal plants comes amid a rapidly shifting landscape for fossil-fuel power.

The Trump administration recently rolled back emissions restrictions for coal- and gas-fired power plants, but a federal judge also ruled TVA broke the law when it approved a $2.5 billion natural gas project at Kingston, creating new uncertainty around another major piece of the utility's generation strategy.

The utility has argued in court filings that it needs the natural gas plant to help meet growing demand from customers. TVA sells electricity to more than 150 local power companies, including the Knoxville Utilities Board, and serves ratepayers from Virginia to Mississippi.