The price of natural gas has been dropping dramatically and is now near a 10-year-low. That's good news for the Tennessee Valley Authority, which is almost ready to start up a power plant in East Tennessee that burns natural gas.
But as 10 News Anchor Emeritus Bill Williams found out on a trip to the plant in progress in Rogersville, the natural gas powered generators in that plant are just part of the story:
In April 2010, Bill first talked with Project Manager Roger Waldrep at the site near the old John Sevier Plant in Hawkins County. At the time, the only construction work on the 550-acre field was some site preparation:
"Since that time we've spent 2.4 million man hours and 18 months building the plant you see behind us that's nearly 92 percent complete," said Waldrep in a recent interview.
In those 18 months, 1100 workers have laid 2-million feet of cable, placed 44 tons of structure steel, poured 45-thousand tons of concrete, and more, all at a cost of around $820-million dollars.
This is a combined cycle plant. Here's how it works: Natural gas is burned in three jet-engine size, quiet-running combustion turbines to produce electricity.
Then the exhaust heat from those turbines makes steam to turn yet another huge turbine to produce more electricity.
"What you see immediately behind me in red is the high pressure steam turbine. Some of you may have seen it come through Knoxville last year on a barge, associated with the generator. That steam is delivered through this large pipe and valve system here to turn the steam turbines for motive power," said Waldrep.
In the control room, a team of operators stays busy monitoring and checking out all the equipment prior to start-up.
Tests have already been run on two of the combustion turbines and operators say they have performed well.
When this plant goes on line in the next two or three months, it will be providing electricity to about half-a-million homes at a very low cost, and almost no pollution. TVA will then have five combined cycle plants operating. They would like to have more.
The John Sevier Combined Cycle Plant is part of TVA's plan to add two thousand megawatts of natural gas power production by the year 2020, to replace older, coal-fired units.