Take an exclusive tour of the Raccoon Mountain Pump Storage Plant

CHATTANOOGA (WDEF) – Raccoon mountain is popular with walkers, bikers and those who want to enjoy the view but few have any idea of what’s going on within the mountain.

There’s a 5 acre lake that TVA set up at the facility in the late 70’s to generate power quickly.

Ashley Henderson takes us on an exclusive tour.

Since 9-11, the thirty-eight floor elevator tour to see the generators has been closed to the public. But we got a rare tour inside the facility from 70 feet below the river level today.

The ramp to below the level of the Tennessee River, goes to a facility that was carved out of the inside of the mountain.

Manager Thomas Gamble tells us ”It’s essentially a huge storage, bulk energy storage is what the lake is utilized for, so that supplies power to roughly a million homes in the Tennessee Valley so that’s great benefit, quick start, quick shutdown machines so we can help with any kind of system disturbance, unit trip or storms come though and we lose a section of the system or things of that nature we can help the system absorb that fairly quickly, generally within a two to three minute window we’ll be able to stabilize the system up to that 1600 megawatt capability.’

Yes, he said within 3 minutes. It takes up to 16 hours to start up a coal fired plant.

“Originally they were, pump storage was designed around support of nuclear facilities, if you were to lose a twelve hundred megawatt Sequoyah or Watts Bar machine, they could call us, we could recover that load for up to 20 hours.”

This facility cost 300-million dollars in 1979 dollars….but today it’s a valuable piece of the TVA system.

What about the cost to operate?

“When we’re pumping at night, generally you consider that a cost, we’re having to pay to fill the reservoir, but by balancing that with our system, we’re enabling our coal or gas fleet to prevent shutdowns.”

It’s costs 20 to 30 dollars per megawatt hour to pump water into the lake….because it’s done at night when power is cheaper. But, it can be sold at 40-60 dollars per megawatt when it’s sold.

“The red buswork, is actually the twenty-three thousand volt system, coming from the generator out to the main transformer.”

This is a sight most people will never see, in one of the few pump stations in the world. And after almost 40 years its still paying it’s way.

The general public still cannot tour the Turbine Bay inside the mountain but the visitors center remains open, with interactive displays which document the history of TVA, and the building and operation of the pump storage facility.

In Chattanooga, Ashley Henderson, News 12 Now.