POWER September 2012 - 40

TOP PLANTS
John Sevier Combined Cycle
Project, Rogersville, Tennessee
Owner/operator: Tennessee Valley Authority
The Tennessee Valley Authority (TVA) is known for its large fleet of coal-fired
plants. With TVA's renewed emphasis on nuclear power and gas-fired generation,
the organization will soon fulfill its new goal: " to be one of the nation's leading
providers of low-cost cleaner energy by 2020. " Construction of the 880-MW John
Sevier Combined Cycle Plant puts TVA one step closer to achieving that goal.
By Dr. Robert Peltier, PE
Courtesy: TVA
T
he Tennessee Valley Authority (TVA) is
a federal utility that provides electricity
to seven southeastern states. Electricity
is produced by a system of 29 hydroelectric
dams, 56 units at 11 coal-fired plants, three
nuclear plants, and 11 gas-fired plants, for a
total of 33,700 MW of installed capacity. The
coal-fired plants produced about 51% of the
electricity generated in 2010. That mix of resources
will change in the future with TVA's
new integrated resource plan that states: " any
needed capacity will be replaced with lowemission
or zero-emission electricity sources,
including renewable energy, natural gas,
nuclear power and energy efficiency. "
Replacement Strategy
The integrated resource plan includes closing
uneconomical coal plants. In August 2010,
TVA President and CEO Tom Kilgore unveiled
plans to idle or retire nine units at several of
TVA's older coal plants, including two units
at the four-unit, 704-MW John Sevier Fossil
Plant (JSF), located near Rogersville, Tenn. In
April 2011, TVA announced additional plant
retirements, including the remaining two units
at JSF that will be " idled " at the end of this
40
year; TVA will " control, convert, or retire "
those remaining two units no later than the
end of 2015. In total, the plan calls for retiring
about 2,700 MW of coal-fired capacity across
the TVA system by the end of 2017.
At the same time, TVA has been busy upgrading
its system with new gas-fired plants.
The John Sevier Combined Cycle Plant
(JSCC) is the fifth combined cycle gas plant
TVA has bought or built in the past five years,
for a total capacity of about 4,000 MW. TVA,
which used little natural gas to produce electricity
only five years ago, now owns gas-fired
plants at Caledonia, Magnolia, and Southaven
in Mississippi and at Lagoon Creek near
Brownsville, Tenn., in addition to its fleet of
combustion turbines located at several of its
coal-fired sites. Kilgore noted during a May 4
conference call with the financial community,
" We started [the move to gas-fired plants] long
before low gas prices, so that just shows you
that a balanced portfolio really does work. "
A More Efficient Option
JSCC, located adjacent to JSF, was approved by
the TVA Board in June 2009 in response to a
ruling by the U.S. District Court for the Western
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District of North Carolina regarding control of
interstate emissions. The court set an accelerated
schedule (compliance by Jan. 1, 2012) for
TVA to install emissions control equipment on
all four units at JSF. TVA determined that the
short compliance schedule combined with an
extended conversion shutdown was much more
costly than shuttering two units, idling the remaining
two units, and building a new gas-fired
combined cycle plant.
Reliable electricity production from the
new plant is essential because it, according to
a TVA spokesman, " anchors the eastern portion
of TVA's power system, the absence of
generation would increase the risk of power
supply disruptions and reduce overall power
system reliability. "
In April 2008, URS was contracted to
perform engineering and procurement for a
combined cycle conversion project in Gleason,
Tenn. Then, in spring 2009, that project
was deferred and the engineering and material
were redeployed to the JSCC project.
In March 2010, Kiewit Power Constructors
Co. (KPC) was awarded a contract for
construction of JSCC with a June 2012
completion target date. The air permit was
POWER | September 2012
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POWER September 2012

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