POWER October 2019 - 24

TOP PLANT
erating its $1.1-billion, 1,360-MW Brunswick
County Power Station in 2016; the
two plants are separated by seven miles.
" From the outside, [the two plants]
look very similar, " said Humberson.
" [Brunswick] was a blueprint in how the
Greensville plant is laid out, but once you
pull back that layer, the plants are very
different animals. "
Humberson noted several of Greensville's
details that he said set it apart from
any other U.S. power plant. " This is the
first power plant in the U.S. that had to
meet medium-risk [cybersecurity] NERC
[North American Electric Reliability Corp.]
requirements prior to going into service, "
he said. " We had teams and teams of
people focused on how to meet NERC
medium-risk requirements before entering
commercial operation. "
MHPS Turbines
The M501J gas turbine, with a 15-stage
axial-flow compressor, can operate
at 1,600C inlet turbine temperature,
and provide up to 64% net thermal efficiency
in combined-cycle operations.
The Greensville turbines were built at
MHPS's manufacturing facility in Savannah,
Georgia.
The plant's design also includes an 80cell
direct dry air-cooled condenser (ACC)
and a thermal energy storage facility that
includes a thermal energy storage tank
and a chiller system.
Other components of the plant include
an auxiliary boiler of 185-MMBtu-per-hour
capacity, a diesel-fired emergency generator,
two propane-fired emergency generators,
and a diesel-fired water pump.
The power produced at Greensville is
transmitted to the Rogers Road switching
station-built new for the plant-via
two 500-kV transmission lines.
" The station is the largest power block
of its kind in the world, " Humberson said,
noting " the three combustion turbines to
produce electricity, " and the steam generation,
" which is used to make even
more electricity.
" Environmentally, especially in terms
of carbon emissions, Greensville is one
of the cleanest natural gas-powered stations
in the country, " Humberson said.
" The station's air permit has the strictest
CO2 limits in the nation. In our air permit,
CO2e [carbon dioxide equivalent] is layered
throughout. We also are bound by
the heat rate on our plant, and we built
in a CO2e limit that we knew we could
achieve. We have a greenhouse gas,
heat rate emission limit that we have to
correct back to. We don't have any start24
up
exemptions, we have limits based on
what we can do when we start up. "
Koonce highlighted the project's environmental
targets when construction
began in 2016. " The most important part
is that we believe the Greensville power
station will be the cleanest and most
environmentally friendly
combined-cycle
facility anywhere, " he said. " Virginia
has imposed stricter carbon limits on
Greensville than any regulatory agency
on any existing fossil-fired facility anywhere.
And we expect to live up to that
strict standard. "
Commitment to Safe and Quality
Construction
" Greensville was no easy project, " Humberson
said. " We worked exceptionally
hard, we got in on time, we got in on budget,
even though we were delayed about
72 days getting our air permit. Fluor was
our EPC [engineering, procurement, and
construction contractor] on this project
and performed admirably in the face of
all challenges.
" I think it had a lot to do with our relationships
with OEMs (original equipment
manufacturers), with Fluor as the EPC,
to overcome construction issues, " Humberson
said. " It was always 'project first,'
and everyone bought into it. "
Humberson talked about the camaraderie
as the plant was being built, and
how " a family atmosphere " permeated
the project.
" We were getting people committed
with their own personal families. We got
the craft level and all the way up buying
into this plant, " he said. " We had a 0.39
OSHA [Occupational Safety and Health
Administration recordable incident] rate,
with more than 8 million man-hours
[worked]. We took more of a family approach
with safety ... brother's keeper, we
are all in this together. We actually shut
the site down in July 2017, and all our craft
workers were able to bring family members
to the site. We asked the question,
'So who is it you go home for?' "
Humberson said Dominion Energy
organized a plant tour even with several
units still under construction. " There was
lots of clean-up so we could feel comfortable
bringing in thousands of people. It
got workers invested in safety programs.
I like to tell the story of how I was walking
around with one gentleman [that] I
thought was a worker, but it was his dad
that worked at the site. He told me how
thankful he was for the opportunity to visit
the site; he told me, 'My whole life I've
never known what my dad did.' Workers
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POWER POINTS
Winning Attributes
✔ The Greensville Power Station was
built in two years, with construction
finishing on time and on budget.
✔ Dominion Energy said the plant has
the largest power block of its kind in
the world, using three combustion
turbines to produce electricity and
steam, with the steam used to make
more electricity.
✔ The project had an exemplary
safety record, taking a " family
approach " to safety, according to
the director of generation projects
and generation construction.
were saying 'thank you' for letting them
experience their work with their families.
We had probably the happiest construction
site I've ever seen in my life. "
Along with MHPSA and Alstom, other
companies involved with the project included
Fluor, the EPC; AMECO, a Fluor subsidiary,
which provided construction tools and
rentals for the project; and Enexio, which
provided
the ACC. Fluor subcontracted
Timmons Group to provide the engineering
design for three miles of road renovation to
support the plant's construction.
Generator step-up transformers and
unit auxiliary transformers were provided
by the SGB-SMIT Group. The plant
uses the Emerson Ovation distributed
control system.
The Greensville plant is expected to
provide up to $7 million in property taxes
for Greensville County in its first year of
operation, and studies show the plant
will have about a $36 million annual impact
on the area. The plant is staffed by
49 full-time workers with dozens more
jobs tied indirectly to the plant.
Greensville also has a positive community
impact beyond providing electricity
and revenue to the Southside area.
" We actually built a welding lab at
Southside Virginia Community College, "
Humberson said. The lab, built in a partnership
with Fluor, Dominion Virginia
Power, Greensville County, AMECO,
and the Virginia Tobacco Commission,
opened in March 2017. " We teamed up
with the local community college and
built a welding lab. The first students
to come out of the program worked at
Greensville, " he said. ■
-Darrell Proctor is a POWER
associate editor.
POWER | October 2019
http://www.powermag.com
POWER October 2019

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