POWER September 2014 - 36

TOP PLANTS
San Pedro de Macorís typifies the challenges
facing the nation as a whole. The city
gets much of its power from a 153-MW floating
engine plant supplied by Wärtsilä. More
than once, the plant has been forced to shut
down when its owner, EGE Haina-one of
the firms spun off from CDE-was unable to
pay its fuel bills.
EGE Haina, the nation's largest generator
by installed capacity, needed to expand
its generation in the area as well. That would
soon lead to an unusual partnership, one that
would eventually build the largest power
plant in the Caribbean, the largest plant ever
delivered by Wärtsilä, and one of the largest
engine plants in the world.
Double or Nothing
In 2011, Barrick approached Wärtsilä about
building a gas engine plant that would support
operations at Pueblo Viejo. Barrick-
which had previously purchased two other
plants from Wärtsilä-needed a highly reliable,
low-maintenance solution that would
function efficiently in the hot, humid tropical
environment. Wärtsilä already had significant
experience developing plants in the
Dominican Republic, with a total of 900
MW of generation then in operation (including
EGE Haina's barge plant). It proposed a
plant based on its combined cycle Flexicycle
design employing its 18V50DF engines.
The dual-fuel, 17.1-MW 18V50DF, introduced
in 2007, has been deployed in both
marine and power generation applications.
It can run on natural gas and light or heavy
fuel oil, and can change fuels on the fly.
When operating on gas, it has an extremely
low emissions profile. In Flexicycle configuration,
the engine exhaust is directed
through a heat-recovery steam generator,
and the steam is used to drive a steam turbine.
Flexicycle plants can achieve efficiencies
approaching those of gas turbine
combined cycle plants and can maintain that
high efficiency across their full operating
range (unlike gas turbines).
In September 2011, Barrick and Wärtsilä
signed a turnkey contract to deliver a
215-MW Flexicycle plant at Pueblo Viejo
comprising 12 18V50DF engines and an associated
steam cycle.
EGE Haina had already been in discussions
with Barrick about how the mine's
large power needs would affect the local grid.
When plans for the new plant began taking
shape, EGE Haina's management realized
the efficiencies and savings that could be captured
by joining the project. In December, it
signed a separate turnkey contract with Wärtsilä
for a nearly identical plant on the same
site. Thus, the single 215-MW plant became
a parallel two-unit 430-MW project, the larg36
1.
Two plants, one site. The Quisqueya I and II plants in the Dominican Republic are
nominally separate but operate as one. Both plants send power to the national grid, though
Quisqueya I primarily supports the nearby Pueblo Viejo gold mine. Waste heat recovery systems
on the two plants each drive a steam turbine generator that supplements power from the engines.
Courtesy: EGE Haina
est Wärtsilä had ever delivered.
The combined plant would cost about
$700 million, with Barrick and EGE Haina
each contributing $350 million (again, via
separate contracts). That figure represented
almost a third of the total energy infrastructure
investment in the Dominican Republic
over the previous 13 years, according to government
data.
Construction and Commissioning
Site work started in February 2012. The initial
plan was for a four-month gap between
the two projects, but delays in permitting
meant that both plants had to be constructed
on a very similar time schedule. The shift in
schedule meant that a large number of tasks
had to be carried out in parallel, and the engine
halls had to be built more or less simultaneously.
This created a more crowded job
site, which put extra pressure on site supervision
and workers.
The simple cycle system was completed in
the summer of 2013. Performance tests began
in September, and the completed plants
were handed over in December. Construction
peaked at 1,400 workers; approximately
3.5 million man-hours were put in by final
completion.
Quisqueya I is owned by Barrick, while
Quisqueya II is owned by EGE Haina, but
the plants function more or less as one, from
a single control room operated by EGE Haina
personnel. Quisqueya I powers the Pueblo
Viejo mine-which reached commercial
production shortly before the plant was complete-with
excess electricity flowing to the
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grid; Quisqueya II delivers power solely to
the grid. About 150 workers are employed at
the site (Figure 1).
The startup of the Quisqueya plants had an
immediate impact on the Dominican energy
market. The CNE announced shortly afterward
that Quisqueya's generation had caused
a 30% drop in spot prices for electricity, from
$0.20/kWh to $0.14/kWh. This resulted in
significant savings to both end users and
CDEEE, which purchases up to 20% of its
power on the spot market.
In addition, the large size of the facility,
as well as the high flexibility of an enginebased
plant, means Quisqueya is also capable
of providing frequency support for the national
grid.
Though the plants are initially being run
on fuel oil, they will switch over to natural
gas as soon as reliable supplies are available.
Over the long term, it is hoped that
fuel for the plant will come from a liquefied
natural gas import terminal being proposed
for San Pedro de Macorís. This would supply
not just the Quisqueya plants but also
several other plants in the area that are under
construction or planned for conversion
to gas firing.
For leveraging a public-private partnership
to supply badly needed generation and
frequency support as well as supporting an
important industrial project in a difficult development
environment, Quisqueya is a deserving
Top Plant. ■
-Thomas W. Overton, JD is a POWER
associate editor (@thomas_overton,
@POWERmagazine).
POWER | September 2014

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POWER September 2014

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