POWER August 2017 - 22

PLANT OF THE YEAR
3. When it rains, it pours. Midway through the construction period, the team was
forced to contend with the Texas coastal plain's propensity for flooding. On Memorial Day weekend
in 2015, the Greater Houston area was drenched by a historic downpour. The project site
recorded 11.5 inches of rainfall. " When we came back to work on Tuesday morning, the entire
carbon capture site was underwater, " TIC's Robert Wolosyn recalled. TIC's consortium partner
Mitsubishi Hitachi Industries credited TIC with having the foresight to lime-treat all its backfill
material, which kept the water from permeating and allowed for quick drainage. " All we had to
do was scrape off about an inch of the top layer that was very muddy and it was all hard and
good, and we were able to go back to work, " said Wolosyn. Courtesy: TIC
NRG, which had envisioned the project
as a small-scale commercial carbon capture
project, was bent on choosing a technology
that was as mature as possible. " Only two
passed the test, " Greeson said. One was Flour
Corp.'s advanced Ecoamine FG Plus technology,
equipment tested on a large scale at a
plant in Bellingham, Mass., which promised
to capture about 400 thousand tons of flue
gas CO2 from a 60-MW unit.
The second technology under consideration
was developed by MHI in conjunction
with Japan's Kansai Electric Power Co. (see
sidebar, " A Highly Tested Carbon Capture
Technology " ). The lure of MHI's technology,
according to Greeson, was that it had been
demonstrated at a large scale at Southern
Co.'s Plant Barry in Alabama. A memorandum
of understanding and a confidentiality
agreement with MHI allowed NRG to assess
the technology in detail with the help of outside
engineering firms. Greeson also credited
Southern Co. and the Electric Power Research
Institute for allowing NRG to tour the
DOE-funded demonstration project at Plant
Barry, which captured and injected 500 metric
tons of CO2 per day (about 90%) from a
25-MW flue gas slipstream.
power generators, it managed to thwart a
hostile takeover by Exelon Corp., and was in
the process of revenue diversification with
the acquisition of Reliant Energy's retail
business in Texas. The company was also
actively decarbonizing its fleet-which was
then 32% coal-fired-and was considering
a 2.7-GW expansion at the South Texas
Project nuclear plant, along with new wind
farms in West Texas, solar in California and
New Mexico, and multiple gas-fired power
projects in California, Texas, and throughout
the Northeast.
Investor documents from 2009 show that
NRG wasn't confident that federal climate
change legislation being considered at the
time would " stick. " As Greeson recalls, the
company's impetus to build a carbon capture
system was simply to preserve its existing
fleet in a low-carbon environment. " So, we
formed a small team of folks and said, 'Hey,
we're going to get run over by this issue if we
don't address it,' " he said.
But conceiving a solution was complicated
by three factors, he said: First, how
the carbon technology worked; second,
how to sequester captured carbon; and
third, how to pay for it all. " We're not a
government entity, and we're not a ratebased
company, " he said. " Everything we
do is subject to competitive pressures,
competitive markets. And so, we can't just
22
raise the price of electricity, because then
customers won't buy our products. "
The NRG team ultimately settled on the
idea of building a carbon capture system at
the W.A. Parish facility near Houston, mostly
because the site offered access to a number
of opportunities to sequester the CO2 in oil
fields that were good candidates for enhanced
oil recovery (EOR). " Using the plant
in Houston, we kind of had an environment
where there was an opportunity to be successful
on all three fronts, " Greeson said.
Also, he noted, the Texas Legislature had just
passed " very strong " incentives to abate half
of the EOR severance tax, and another substantial
reduction if a project uses anthropogenic
CO2. The facility also benefited from
franchise tax credits. The capture system,
too, offered exemptions from property taxes
because it is considered a pollution control
device, and a substantial amount of equipment
used in the facility was exempt from
sales tax.
Fleshing Out the Project
At that point, the project was still a skeleton
of an idea that required " putting flesh on the
bones, one by one, " Greeson said. That entailed
selecting the technology, applying for a
grant from the Department of Energy (DOE),
and making preliminary arrangements with
an oil field.
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" In the end when we were doing our final
capital raise with our lenders and our partners
and NRG's board, having Plant Barry
successfully operate was critical to everyone
having confidence that this technology
would work at the scale we were proposing, "
Greeson said.
The biggest factor was simply economics.
To cover costs required to capture CO2 and
deliver that gas to the oil field, NRG reasoned
that the project needed to be sized to the oil
field. NRG ultimately settled on injecting the
gas into wells to optimize production at the
West Ranch Field in Jackson County. However,
the 11,500-acre field discovered in 1938
and now operated by exploration and production
company Hilcorp is about 80 miles
southwest of the W.A. Parish site, and transporting
the gas would require a 12- to 16-inch
buried pipeline.
" So, as we settled on which oil field was
going to be our target, we realized because of
sub-surface simulations and production simulations,
that the amount of CO2 [proposed
by the 60-MW capture system] was not going
to be enough to create an upfront loaded response
of oil from the oil field, " Greeson explained.
" We would still get all the 60 million
barrels that we know are in there that can be
produced with CO2, but it might have taken
30 or 40 years to get there. With the increased
amount of CO2 [from Petra Nova], that can
happen in 10 years. "
What it required, NRG determined, was
a massive increase in scale and scope of
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POWER August 2017

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