Inside Cestas

300 MW Cestas project 300 MW Cestas project
Photos: Schneider Electric
Schneider Electric leveraged its global manufacturing footprint to supply electrical components for Cestas.
Space and time
Power electronics and grid connection: Thousands of acres, thousands of electrical
components, vast amounts of wiring: The challenges facing Schneider Electric on the
construction of the Cestas plant were daunting, particularly in the fields of supply
chain and schedule management.
Compared to other widely deployed
forms of electricity generation, photovoltaic
technology is both relatively new
and evolving rapidly, and as such, building
solar PV projects on time and on budget
can be challenging for developers and
contractors. More so when you are building
the largest PV project in Europe, are
attempting to achieve a levelized cost
of electricity below €105/MWh ($115/
MWh), and are racing frantically against
the clock.
Schneider Electric faced all of these
issues as a member of the consortium
that constructed the Cestas PV project in
France. And as one of the world’s largest
suppliers of electrical solutions for a
range of industries, it was well positioned
to meet these challenges.
A giant in Bordeaux
France has long relied on nuclear power
to meet the majority of its electricity
needs, and is behind its neighbors
in Spain, Italy and especially Germany
in terms of the percentage of electricity
demand met with PV. This makes the
nation an unlikely location for the largest
solar PV project in Europe.
At 300 MW, Cestas is much larger than
other PV projects on the continent, and
managed to squeak in to qualify for a relatively
high rate under France’s feed-in
tariff. This program has since become
essentially useless for large-scale PV
plants.
When extremely ambitious and large
projects are announced, industry veterans
are quick to recall others that never
came to fruition, such as a 1 GW megaproject
planned in Serbia. Cestas is a different
story, as the project began construction
last November, and work is
currently underway across dozens of
square kilometers outside Bordeaux, on
France’s Atlantic coast.
Schneider Electric’s role
Mega-projects like Cestas pose difficulties
in many areas, including financing
(see pp. 8 – 10). They also involve technical
and logistical trials, many of which were
borne by Schneider Electric, along with
its partners in the consortium including
EPC Eiffage and mounting systems supplier
Krinner.
The company’s role covered managing
energy “from the solar panels to the highvoltage
grid.” This includes not only supplying
the hardware and software solutions,
but also performing operations and
maintenance services along with its partners.
Components supplied by Schneider
Electric include 200 of its PV Box RT
units, each of which houses two Conext
Core XC 680 inverters, including its Conext
Control monitoring solution.
The project features two notable technical
details. First, it is connected directly
to a 225 kV transmission line, for which
Schneider Electric is building a substation.
Second, it utilizes PV modules
mounted in east and west-facing orientations,
which broadens the plant’s output
over a 24 hour period.
Scale, money and time
The scale of Cestas brings up the question
of how different it is to supply components
to a project of this size. Ultimately,
many of the challenges are the same, only
on a larger scale. This is especially true for
Cestas, which consists of 25 individual
plants, each 20 MW in capacity, spread
across the fields and forests between the
Garonne River and Arcachon Bay in the
Aquitaine region.
Schneider Electric’s challenge was not
only scale, but scale and timing as well.
France’s feed-in tariff contains a penalty
for late construction that can impact the
financial viability of projects. For every
month that a project is completed after a
certain date, the term of the feed-in tariff
is shortened by three months.
“It means that if you connect your project
three months after the time of the
contract, then you lose nine months of
feed-in tariff,” explains Schneider Electric
Director of Solar Power Generation &
Energy Storage for Western Europe and
Northwest Africa, Ignace de Prest. This
deadline is so sharp that few projects end
up qualifying for the full 20 years of the
feed-in tariff.
De Prest also notes that the complexity
of the project translated to lengthy
negotiations between consortium members
and sub-contractors, which intensified
the time pressures. As if this were
not enough, there is the added dimension
of cost. While the feed-in tariff of €105/
MWh is much higher than is currently
offered, it is a disconcertingly low level
for the successful completion of a solar
PV project in Europe.
Global manufacturing, supply
chain mastery
In its role as supplier, Schneider Electric
leveraged its global manufacturing, with
its Conext Core inverters made at a factory
in India, and the RT boxes assembled
and integrated in Spain. “There were
challenges in the fact that the construction
is very quick,” notes de Prest. “We
were delivering more than eight PV boxes
per week for several months.”
High-volume delivery of product manufactured
on several continents can be
inherently tricky. “The standard nature
of our components, the mastering of
global supply chain, and synergies with
other partners of Schneider Electric for
procurement of components and so on
– the fact that we have a very competitive
cost of manufacturing, scale effects –
that’s all related to the competitiveness of
the project,” explains de Prest. “The tariff
is low and there was a lot of competition
for this project.”
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