Note: This story was updated at 8:50 p.m.
An assessment by the Tennessee Valley Authority will evaluate its power generators, including the coal-burning Bull Run Fossil Plant in Claxton, and determine whether the plants will be needed in the future, a spokesperson said Monday.
The focus of the assessment, which could take three to six months, will be on plants that are the least efficient, least cost-effective, and expected to have the highest future costs, TVA spokesperson Scott Brooks said. Plants that fit into that category are the Bull Run Fossil Plant, the one remaining unit (Unit 3) at the Paradise Fossil Plant in western Kentucky near Drakesboro, and combustion turbines (gas turbines), Brooks said. The assessment will look at whether TVA needs Bull Run or Paradise or combustion turbines in the future.
No decisions have been made yet, Brooks said.
He said TVA is assessing its entire generating asset base, including coal, nuclear, natural gas, and hydropower. The public utility is always evaluating its energy mix and making decisions, Brooks said. TVA President and Chief Executive Officer Bill Johnson cited a “mismatch” between energy supply and customer demand, according to S&P Global, which attended a quarterly TVA board meeting in Knoxville on Wednesday.
The results of the assessment will be provided to the TVA board of directors. It’s not clear yet if the assessment will include a recommendation to the board, but the board could make a decision based on the assessment.
Bull Run, which is across the Clinch River from east Oak Ridge, started operating in 1967, and it’s one of the newer coal-burning plants. The 881-megawatt plant can generate enough electricity to power about 400,000 homes. TVA has added the latest environmental controls at Bull Run for emissions and is making changes to go from wet to dry storage for coal ash and other coal combustion residuals, Brooks said.
Regarding the combustion turbines, Brooks said they help meet peak power demands all over the Tennessee Valley. Some of the combustion turbines have been around for decades, and some don’t run all that often, Brooks said. TVA has 87 simple cycle combustion turbines, and besides natural gas, they can burn diesel or fuel oil.
Brooks said the assessment is being driven by current and future demands. TVA’s energy demands are flat to declining, including because of energy efficiency measures that include customers using more efficient light bulbs, appliances, and heating and cooling systems.
“We’re looking at whether we have more generating assets than we need at the lowest feasible cost,” Brooks said.
He said TVA’s goal during the last five years has been a diverse power generation portfolio. That has included shutting down 10 coal units at Johnsonville in 2017 and three units at Allen in Memphis this year, adding nuclear power at Watts Bar Unit 2 and upgrading Browns Ferry, and increasing energy efficiency and the percentage of renewable energy, such as wind and solar power. Hydropower is still about 10 percent of TVA’s power generation portfolio, Brooks said.
The Chattanooga Times Free Press, which attended the TVA board meeting on Wednesday, reported that TVA has shut down 32 of the 59 coal-fired units it once operated, including the 13 units at Johnsonville and Allen, and is reviewing the two units at Bull Run and Paradise. Other units still operating in Tennessee include two units at Cumberland near Nashville, nine units at Kingston, four units at Gallatin, and nine units at Shawnee. Unit 3 at Paradise, which became operational in 1970, has a generating capacity of 1,150 megawatts, enough to supply more than 950,000 homes.
Two other units at Paradise were retired in 2017 and replaced with a more efficient combined-cycle gas plant, according to S&P Global.
The Times Free Press reported that newer natural gas plants that TVA has added to replace its John Sevier, Allen, and oldest Paradise units during the past four years are twice as efficient as the older coal units were when they operated. The newspaper said TVA has shifted its generation mix to get more than half of its its power from carbon-free sources, including its seven nuclear reactors.
S&P Global reported that 58 percent of TVA’s portfolio was coal in 2007, but that figure is now down to 26 percent.
More information will be added as it becomes available.
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