New Units Arrive at Johnsonville

While visiting a General Electric factory in Hungary this summer, Justin McBath and his Tennessee Valley Authority team members got a sneak peek at a new aeroderivative gas turbine that would be headed to a TVA site in New Johnsonville, Tennessee.

On startup, the new unit made a magnificent sound.

McBath and his team were awestruck.

“I’m excited about what it means for the Tennessee Valley as a whole,” McBath, TVA’s senior project manager in Generation Projects and Fleet Services, said.

This technology will be the first of its kind for TVA’s fleet of natural gas plants.

Johnsonville Combustion Turbine Plant is set to receive all 10 of the aeroderivative turbines by summer 2025. Six units have already arrived. When all 10 units are online, it will ultimately add 500 megawatts of new generation to the site.

The plant is also retiring all but four of its 20 existing combustion turbines.

With the four existing units and 10 new units, Johnsonville will have a total operating capacity of approximately 900 megawatts. 

Cleaner Power

Modified from jet engines, aeroderivative turbines are designed to reach full output within 10 minutes, compared to simple-cycle turbines that take 30 minutes to an hour to reach full production.

The new equipment will supplement solar generation on days when sunshine is limited.

“When solar farms cannot produce energy efficiently, these units will kick in to make up that difference,” McBath said.

The advancements should allow for cleaner power production, offering multiple environmental advantages relative to other generating sites.

The new units also have a smaller footprint, allowing for better reuse of the existing site.

The Johnsonville plant also uses the best available selective catalytic reduction technology and carbon dioxide catalysts to control nitrogen oxide and carbon monoxide levels.

“The aeros are being installed to allow for more green power production to exist,” McBath said. “These are the bridge to that.”

The units were designed and constructed at locations across the world, making this a truly global collaboration to ensure they were built to the highest standards.

The newest and best technology helps ensure their success.

 “For me, it’s the excitement around new technology and being able to use it in a unique way that ultimately takes us in a direction towards more sustainable and renewable energy,” McBath said.

These units provide a step toward a cleaner generation mix. They’re a flexible, responsive and reliable addition to the power grid.