POWER September 2017 - 22

TOP PLANTS
World's Most-Efficient Combined
Cycle Plant: EDF Bouchain
Courtesy: GE
When you bring two power giants together to develop a new breed of combined
cycle gas turbine plant, you expect the results to be pretty good. When EDF and GE
installed the first commercial 9HA gas turbine in the Bouchain plant, the outcome
was great: A new world record for combined cycle efficiency-62.22%.
Aaron Larson
I
f you know anything about France's electricity
grid, you probably know it relies
heavily on nuclear power. In fact, since
the late 1980s, uranium atoms have been
used to generate more than 75% of the nation's
electricity-the highest nuclear power
percentage of any country in the world. But
times may be changing.
Nicolas Hulot, the French energy minister
under recently elected President Emmanuel
Macron, in a radio interview on July 10,
said as many as 17 of France's 58 reactors
could be closed by 2025. The move is aimed
at reducing the country's reliance on nuclear
power to 50%.
So, where is France's power going to come
from? The Macron administration pledged to
close the country's five coal-fired power plants
by 2022, so it won't be from that resource.
The long-term goal is to double renewables to
32% by 2030, but variable wind and solar generation
requires a reliable backup. Therefore,
highly efficient natural gas-fueled plants could
offer one dependable solution.
First 9HA Gas Turbine Installed
And when it comes to efficient natural gas22
fired
plants, there are none better than EDF
Bouchain. The 605-MW unit has been recognized
by Guinness World Records as the
most-efficient combined cycle power plant in
the world, with a third-party verified net efficiency
of 62.22%.
The plant was developed under a unique
industrial partnership between EDF and GE.
The unit was constructed with the first commercial
GE 9HA gas turbine, a machine that
has some remarkable capabilities beyond just
high efficiency. The plant can go from startup
to combined cycle operation in less than 25
minutes. It can also be turned down to as low
as 30% of its top generating capability while
still meeting emission requirements. The
flexibility is important for the industry's ongoing
efforts to increase the use of renewable
energy and protect the environment.
The Bouchain location had been host to
two 250-MW coal-fired units, which were
retired in 2015. The new combined cycle unit
has reduced site CO2 emissions by 50%, reduced
SOx emissions by 95%, and cut particulate
emissions to zero. The new unit has
a footprint one-quarter the size of the coal
facility while generating more power.
www.powermag.com
" For those areas in the world where footprint
is an issue, this thing is significant in terms of
power density, " said then-GE Power President
and CEO Steve Bolze during a media event on
June 17, 2016. " It replaces a coal plant. It is on
25% of the footprint of the old plant. It generates
more power with 50% less carbon emissions.
This is a big deal, " Bolze added.
The Bouchain site allowed the old plant's
aero-cooling tower to be reused, which limits
the amount of water pumped into the nearby
Scheldt River. Another big benefit was the
ability to transmit the new unit's generation
via the existing 400-kV underground line.
Delivering a Giant
Construction began on the combined cycle
plant with excavation work and soil preparation
in 2012. Civil engineering work began in
2013. That year, deep foundations were constructed
for the gas turbine, steam turbine,
and generator. It took three months to install
all of the rebar and pour the 2,500 cubic meters
(m3) of concrete needed for the power
train pedestal foundation.
The following year, the first heavy-lift
components began arriving on-site. They inPOWER
| September 2017
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POWER September 2017

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