timesfreepress.com-America's largest government-owned utility is looking to replace its biggest coal power plant with more energy-efficient and cleaner natural gas generation to supply the electricity needs of more than 1.1 million homes in Tennessee and Kentucky.

The Tennessee Valley Authority on Monday released a draft environmental report that recommended the best alternative for its aging Cumberland Fossil Plant in Cumberland City, Tennessee, is to shut down the twin-unit coal plant and replace it with a combined-cycle natural gas generating facility.

But environmental groups are urging TVA to abandon the use of any fossil fuels at Cumberland to help meet the U.S. climate-control targets, including President Biden's pledge that the nation's electricity industry be carbon free within the next 13 years.

"Today's proposal is yet another indication that TVA is ready to move beyond coal, but might get stuck in the past with gas," Amy Kelly, a campaign representative for the Sierra Club's Beyond Coal Campaign in Tennessee, said in a statement after the TVA environmental study was released. "One less coal plant in the Tennessee Valley means cleaner air, safer water, and progress toward reducing climate-disrupting emissions, but replacing coal with another fossil fuel gas plant makes no economic and environmental sense."

TVA officials insist that natural gas can be "a cleaner bridge fuel" essential for maintaining power reliability when the sun doesn't shine, the wind doesn't blow or TVA's nuclear and hydroelectric units are out of service. TVA said it has reduced its carbon emissions by 57% since 2005, which is nearly double the industry average, and continues to reduce its carbon emissions while maintaining its 99.999% reliability of power delivery.

TVA's 478-page study released Monday - and scheduled to be officially published in the Federal Register on Friday - said the Cumberland coal-fired generators are increasingly less efficient and generate too much costly pollution for TVA. The coal units northwest of Nashville were built between 1968 and 1973 and are capable of generating 2,470 megawatts of electricity,

Although TVA has installed wet limestone scrubbers and a selective catalytic reduction (SCR) system to limit both sulfur and nitrogen oxide emissions from Cumberland, the plant remains one of the nation's biggest air polluters, releasing over 8 million tons of carbon pollution into the air each year.

The planned shutdown of the Cumberland Plant and a similar study underway on the closing of the Kingston Fossil Plant follows TVA's earlier closings in the past decade of its John Sevier, Widows Creek, Colbert, Allen and Paradise coal plants.

"The aging coal fleet is among the oldest in the nation and is experiencing deterioration of material condition and performance challenges," the environmental study said of TVA's fleet of coal units, which once included 59 units that supplied nearly two-thirds of TVA's electricity generation. "The continued long-term operation of some of TVA's coal plants, including the Cumberland Fossil Plant, is contributing to environmental, economic and reliability risks."

Among four alternatives considered by TVA for the Cumberland plant, the preferred option is to replace most of the plant's generation with a combined-cycle natural gas plant, which is more efficient and emits far less carbon and sulfur dioxide than the coal units they will replace. TVA spokesman Scott Brooks said Monday that TVA projects it will need to continue to produce power for the area served by Cumberland, especially as more transportation and industrial customers electrify cars and machinery now powered by gasoline, propane, and natural gas.

TVA will take public comments on its new draft environmental statement through June 13 and will host three meetings about Cumberland's future that will be open to the public in May.

TVA will release a similar draft environmental study on its Kingston coal plant later this summer, Brooks said.

TVA is proposing to retire one of the Cumberland units as early as 2026 and no later than 2030 and to shut down the other unit by 2033. TVA has set a goal of cutting its total carbon emissions by 80% below the 2005 levels by 2035 by phasing out the last of the 59 coal-fired units TVA once operated.

The Sierra Club said if TVA chooses to build new methane gas plants and pipelines, they would be obsolete in just 10 years due to TVA's own carbon reduction commitments, leaving TVA ratepayers stuck paying the bill for plants that can't be used.

"Replacing the Cumberland coal plant with gas is a move back to a time when there weren't better options available," JoAnn McIntosh, a Sierra Club volunteer who lives in Clarksville near the Cumberland plant, said in a statement Monday. "Renewable energy and storage can now provide that replacement power as reliably and more economically than gas, and without the environmental impacts that are making our world increasingly less habitable for us and our children."

Environmental groups are urging the U.S. Senate to confirm three new directors to the TVA board. The nominees by President Joe Biden include two long-time environmental activists who are expected to be warier about building any new fossil fuel generation.

The Senate could vote on the three nominees next month, but TVA already appears to be moving toward gas-fired generation, at least in part, for the Cumberland plant.

Last November, the TVA board delegated to CEO Jeff Lyash the decision about future alternatives for both the Cumberland and Kingston coal plants, and the board allocated $3.5 billion for new gas-fired generation, according to TVA's annual financial report filed with the U.S. Securities and Exchange Commission.

Separate from TVA's review, Tennessee Gas Pipeline Company, L.L.C., a Kinder Morgan, Inc. company, also has submitted a request to the Federal Energy Regulatory Commission to construct a 32-mile natural gas pipeline to the Cumberland plant site to fuel the proposed new gas-fired generation. Under the proposal submitted last October, the pipeline company would build a 30-inch pipeline lateral originating from Kinder Morgan's existing line in Dickson County, Tennessee to provide up to 245,000 dekatherms per day of additional natural gas transportation for TVA at Cumberland.