TVA to build 1,450 MW combined-cycle plant despite EPA concerns

The new plant would replace retiring coal generating capacity.

TVA to build 1,450 MW combined-cycle plant despite EPA concerns
(TVA plans to retire the two-unit coal-fired Cumberland Fossil Plant in Stewart County, Tennessee Source: TVA.)

TVA will proceed to build a 1,450 MW combined-cycle natural gas plant despite concerns voiced by environmental regulators.  

The new facility would be built on the site of the two-unit coal-fired Cumberland Fossil Plant in Stewart County, Tennessee.

TVA plans to retire Cumberland. The first coal unit would retire by the end of 2026 and the second unit by the end of 2028. Before the first unit retires, TVA would build the new combined-cycle plant to be operational by 2026.

TVA, the largest public utility in the U.S., plans to consider a wide range of generation options to replace the second unit.

However, the Environmental Protection Agency has said the new combined-cycle project is at odds with President Biden’s clean energy goals.

The utility provided the EPA with a final environmental impact statement in early December, analyzing alternatives for replacing the Cumberland plant. It compared the costs and benefits of two types of natural gas plants as well as a solar array with battery storage. The analysis recommended a combined cycle natural gas plant as the preferred alternative. It determined that the solar array would cost $1.8 billion more and could not be completed by the utility’s 2026 deadline.

The EPA issued a detailed response to the analysis on Jan. 6, writing that TVA relied on “inaccurate underlying economic information” and “may continue to underestimate the potential costs of the combined cycle gas plant and overstate the cost of solar and storage.”

EPA added that TVA also failed to account for the opportunities presented by recent federal legislation providing $375 billion over 10 years for clean energy projects.

TVA says its decision was made following a “multi-year, transparent, and public process” and that the natural gas plant at Cumberland will deliver up to a 60% reduction in carbon emissions from the site.

“Replacing retired generation with a natural gas plant is the best overall solution because it’s the only mature technology available today that can provide firm, dispatchable power by 2026 when the first Cumberland unit retires – dispatchable, meaning TVA can turn it off and on as the system requires the power,” said Jeff Lyash, TVA President and CEO said.

Documents related to TVA’s decision can be found here.

Biden has set a goal of a carbon-pollution-free energy sector by 2035 that TVA has said it can’t achieve without technological breakthroughs in nuclear generation and energy storage. TVA has set a goal to reduce greenhouse gas emissions by 80% by 2035, compared with 2005 levels.

The Cumberland Fossil Plant is the largest generating asset in the TVA coal fleet.

Along with a second coal-burning plant, Bull Run, Cumberland went offline during a deep freeze over Christmas weekend. Along with unspecified “issues” at some of TVA’s gas plants, the outages forced TVA to resort to rolling blackouts for the first time in its 90-year history. TVA has said it is investigating what went wrong but has provided few details.

This article includes reporting from The Associated Press.