The federal government’s Tennessee Valley Authority will replace one of its large and elderly coal-fired power plants with a new combined-cycle natural gas generator, rejecting pleas from environmentalists for a replacement with renewables. The nation’s largest public utility, TVA is moving away from coal, once its dominant source of power, in order to reduce carbon dioxide emissions.
The giant generating agency plans to shut down its two-unit Cumberland plant, with the first unit schedule to close in 2026 and the second in 2028. Each unit has a generating capacity of 1,235 MW. The first unit went into service in March 1973 and the second in November of that year. The plant featured two of tallest smokestacks in the world at 1001 feet, designed to lift the flue gas from the plant far into the atmosphere to disperse it. For years, TVA insisted that its federal status meant it didn’t have to follow US Environmental Protection Agency pollution control rules. The 1990 Clean Air Act amendments made clear that TVA was subject to EPA rules and the power agency in 1994 installed to wet limestone flue gas scrubbers, bypassing the tall stacks in favor of shorter ones.
Cumberland is one of only five coal-fired stations still in the TVA system.
TVA’s decision to go gas at the Cumberland site was the result of a final environmental impact statement (something TVA also once said it need not undertake), based on a draft EIS released this April as part of its 2019 Integrated Resource Plan. The draft evaluated demolishing the coal-fired plant and replacing the capacity with combined-cycle gas at the Cumberland site, simple-cycle gas turbines at other existing TVA sites, or solar and storage “primarily at alternate locations.”
The TVA draft concluded that the combined-cycle route was the preferred and least costly, with the combustion turbine option adding $737 million to the project, and the solar option $2.311 billion more expensive. TVA published the final EIS last Friday (Dec. 2), and quickly adopted its recommendation.
In choosing the gas option, Jeff Lyash, TVA president and CEO, said, “This transparent process is one of the ways that TVA is working to build a clean energy future which will enable ongoing and future growth across the region. Our focus is on ensuring that we provide affordable, reliable, resilient, and clean energy for generations to come.”
Evaluating the solar option, TVA found that solar and battery storage technology is “energy limited,” requiring transmission upgrades, including new lines and substations, wouldn’t be in place by the 2026 retirement of the first Cumberland unit, and would need some 20,000 acres of land, compared to 30-50 acres for the combined cycle capacity on the existing Cumberland site.
Jacinda Woodward, TVA senior vice president for power operations, added, ““The amount of solar and storage required to replace a Cumberland Fossil unit is also more expensive – $1.8B more expensive per the final EIS – and it requires transmission upgrades that could take more than a decade to complete.”
TVA’s decision drew fire from environmentalists. The Associated Press quoted Eric Hilt of the Southern Environmental Law Center, “In order to fight climate change and better serve its 10 million customers, TVA must scrap its gas plans and should instead use this opportunity to become a national leader in the clean energy transition by investing in renewable energy options – like solar power, wind power, and battery storage – that are affordable, effective, and available right now.”
Before joining TVA in 2019, Lyash, 61, served as president and CEO of Ontario Power Generation Inc., one of the largest generating companies in Canada. He had also worked in senior positions for CB&I Power, Duke Energy, and Progress Energy. He has a mechanical engineering degree from Drexel University and held a senior reactor operating license from the US Nuclear Regulatory Commission. He is the highest paid official in the US government, at about $9.8 million in salary, performance bonuses and benefits in the fiscal year ended Sept. 30. In contrast, Tom Fanning, CEO of Atlanta-based Southern Co., got $15.8 million last year, according to the Atlanta Journal Constitution.
–Kennedy Maize