Federal public utility Tennessee Valley Authority on Tuesday said it would idle nine coal-fired power units totaling nearly 1 GW at three power plants starting in 2011. Utility officials said the plans were part of a strategy to replace older and less-efficient coal-fired units with “low-carbon” and “carbon-free” generation.

The units to be idled are: Shawnee Unit 10 near Paducah, Ky.; John Sevier Units 1 and 2 near Rogersville, Tenn.; and Widows Creek Units 1-6 near Stevenson, Ala. Two units at the Widows Creek plant will be idled in fiscal year 2011, and four other units there will be idled between 2011 and 2015. Shawnee Unit 10 will be idled and evaluated for possible conversion to biomass fuel. Two units at John Sevier will be idled within the next four to five years.

"Much of our stakeholder input and other assessments point toward a greater reliance on nuclear power and energy efficiency and less reliance on coal," said TVA President and CEO Tom Kilgore. "Replacing some coal with other, cleaner fuel sources allows a reduction in air emissions including carbon. One of TVA’s key goals is to improve air quality."

No employee layoffs are associated with the units being idled in 2011, TVA said. "We will work to lessen the impact on employees," Kilgore said. "We are looking at a number of ways to create new opportunities and options for most, if not all, employees affected. We do not expect that involuntary staffing reductions would be necessary, but we can make no guarantees.”

The TVA coal fleet consists of 59 units at 11 plants with about 15,000 megawatts of generation. The Watts Bar Fossil Plant, which was shut down in 1983, was the last TVA coal-fired plant to be retired.

TVA said that it had spent $5.3 billion on reducing air emissions. "Last year, sulfur dioxide and nitrogen oxide emissions for the TVA coal fleet were about 90 percent lower than during their peak years," Kilgore said.

He added that about 8,000 MW of its fleet were equipped with advanced environmental controls and will remain part of TVA’s long-term generating capacity. Other units totaling about 6,000 megawatts would require scrubbers or other advanced environmental equipment additions in the future. Those units will be evaluated to determine whether to install controls, idle them, or replace them with alternative generation.

The loss of 1,000 MW—about 3% of TVA’s combined capacity—would not be a problem for TVA to offset, Kilgore said. Two gas-fired generation plants at John Sevier and nuclear power units coming online will cover the loss, he said.

The public utility’s fleet currently comprises 29 hydroelectric dams, 11 coal-fired plants, three nuclear plants, and 11 natural gas–fired facilities.

Last week, the TVA board approved a 2011 budget that calls for $248 million for work at the Bellefonte nuclear site in North Alabama to maintain the option for future power generation. Next year, the TVA board will reportedly decide whether to complete construction of Bellefonte 1, which was halted in 1988 when the unit was almost 90% complete. The 2011 budget also includes $635 million for construction of the Watts Bar 2 nuclear facility in East Tennessee, scheduled for completion in 2013.

The budget also includes $314 million for construction of natural gas–fired power generation and $351 million for environmental improvements at coal-fired plants.

Sources: TVA, POWERnews