Our Projects

Our Projects

Current Projects

Clemessy, member of the consortium building the largest solar farm in Europe

In November 2014, Clemessy, as leader of a consortium, won the contract to design, build, operate and maintain Europe's largest photovoltaic power plant in Cestas (F).

Work began as soon as the contract had been signed.

It required mobilising the expertise of:

  • RMT, subsidiary of Clemessy, for the engineering and supervision work, as well as leading the consortium
  • Eiffage Travaux Publics to install the tracks
  • Eiffage Energie Aquitaine associated with Eiffage Energia for the connection work
  • Schneider Electric for the electrical conversion chain
  • Krinner France associated with Krinner Germany for the foundations to be screwed, les structures porteuses et la pose des solar panels.

This project developed by Neoen, one of the leading French players in the field of renewable energies, will represent an overall power capacity of 300 MWp (megawatt peak).

The facility covers an area of over 250 hectares in the vicinity of Bordeaux. It is comprised of 25 sections of 12 MWp.
The farm is connected directly to the very high-voltage grid and come into service in October 2015. Each year it produces over 350 gigawatt-hours, which corresponds to the household consumption of the whole population of Bordeaux.

The Constantin solar farm in figures :


plants or SPVs

983 500

305 Wc photovoltaic modules

16 542

metal tables supporting the modules

3 700

km of solar cables


km of buried cables


km of MV cables

3 826

string boxes


prefabricated 33 kV alternating current transformer substations (including 400 inverters and 200 step-up transformers)


km of internal trails


225 kV substation including two 225 kV/33 kV transformers with a capacity of 140 MVA

Follow the progress of the biggest solar power plant in Europe :

  • Octobrer 2015
    • September 2015
      • Ten months after starting the construction work on site, the Cestas solar power plant produced its first kW on Wednesday 30th September at 11.00am.
        Production started on one of the 25 power plants which make up the whole solar park. In accordance with the time schedule, the other power plants will be progressively brought into service up to the beginning of November.

      • All the construction work is finished

      • The no-load tests on the 200 PV Boxes are finished and commissioning of the substation went according to plan.
    • July / august 2015
    • June 2015

      • The modules continue to be installed efficiently, with a peak of 15,000 in one day!

      • The mechanical tests on the HV substation are finished and the live tests have started.

      • A showroom intended for the general public and in particular children allow them to discover the history of solar energy and how it works along with the key figures concerning the Cestas facility.
    • May 2015

      • The work of installing the screws is complete.

      • The installation of the modules goes on according to plan and is over 70 % complete.

      • The work of installing the PV Boxes continues. Dry runs have been carried out on 6 SPVs.
    • May 2015

      • The work of installing the screws is complete.

      • The installation of the modules goes on according to plan and is over 70 % complete.

      • The work of installing the PV Boxes continues. Dry runs have been carried out on 6 SPVs.
    • April 2015

      • The buried cable work is totally completed.
      • The MV test go normally.

        • The teams of electricians working on the substation have finalised the installation of the HV equipment.
        • The main LV boards, 48V charger and inverter and the control cabinets have been installed in the control room.
        • RTE carries out work in the HV substation and implements its equipment

        • The work is over one week ahead of the tight erection schedule put in place at the beginning of the contract.
        • The modules continue to be installed efficiently and over 50 % have been installed.
        • Like a field of light, the solar energy production plant now forms part of the landscape.
      • March 2015

        • The number of hours worked passed the 130,000 mark at the end of March. The workforce on site continued to increase and reached an average of 250 people. No accidents have been recorded at this stage of the project. Congratulations to all the teams involved.

        • The SJB boxes (marshalling and protection boxes) are manufactured in our Colmar workshop. Over 3,800 boxes are assembled. Each of them has a barcode which allows them to be identified and located in the power plant.
        • Anticipation guides our experts since the beginning of the project. Clemessy, who will carry out the maintenance and operation of the solar power plant, incorporated the maintainability of the power plant as early as the engineering and design phase.
        • At this stage of the sitework, our teams are validating the design of the washing machine which will perform the cleaning of the 983,500 photovoltaic modules, a prototype developed with our partners especially for this project, which includes very strict requirements (max. width of 1.2 m to be able to pass between the panels).

        • The HV substation building is now finished and the equipment is installed.
      • February 2015

        • The company Krinner continues to install screws at the average daily rate of almost 2,000 screws. The installation of the modules is just as efficient with a peak of 7,400 modules a day.

        • The overhead cables for connecting the modules  is implemented by Eiffage Energia and the first continuity tests are carried out.
        • The delivery and the installation of the PV Boxes (Schneider) for the first power plant are completed.

        • Deliveries of the modules to the site reach a peak of 16 containers per day.
        • Paying particular attention to the quality of the modules, a new visit to China enables us to inspect the latest panels manufactured and to finalize the formats and circulation of the test reports.
        • At the same time, the mobile test laboratory for the modules on site is operational and its capacity progressively increases.
      • January 2015

        • The assembly of the modules' supporting structures has considerably increased; there are now 4 complete SPVs.
        • The logistics system is set up to allow transportation from the port of Bassens: unloading on site via a dedicated quay and storing the modules in three tents thus make it possible to create a buffer stock directly on site.

        • The work of installing the modules begins on 2 SPVs.
        • The overhead electrical work, as well as the installation and connection of the boxes begin.

        • The building site is located in a locality and an area of major interest as regards biodiversity (Landes d'Aquitaine region). It is home in particular to the “fadet des laîches”, an endangered species of butterfly. An office of ecologists was contacted to make an assessment and define the conditions required for it to be properly preserved and developed in line with the restrictions imposed by the administrative authorisations.  This relates in particular to the development and protection of a wetland within the space of the site..
        • The work of consolidating the vegetation on the boundaries of the land started in order to take advantage of a favourable period and to allow the development of the plants before the facility is brought into service. The choice of species was given very particular attention.
        • Monitoring of the fauna and flora within the wetland was put in place. It has already revealed a significant colonization of amphibians



      • December 2014

        • December saw an acceleration in the work carried out on the site with increased mobilisation and the start of the construction work on the first 6 plants.

        • The installation of the foundation screws is finished on two power plants and the assembly of the modules' supporting structures has started on one power plant.
      • November 2014

        • The earthworks for the tracks come to an end.
          In total, the future solar farm will criss-crossed by 24 km of tracks.

        • The base camp is functional and will be completely finished within a few weeks to accommodate the consortium companies and the subcontractors.
        • At the peak of the building work, more than 250 people will be mobilized to build the Constantin solar power plant, the largest photovoltaic power plant in Europe.

        • The work on the trenches and buried electrical cables has started, as has the work on the foundations of the HV substation.
        • The first screws on the boxes’ mounting brackets are put in place.

        • Innovation and anticipation are the watchwords for the project management team.
          A significant amount of prior preparation work, supplemented  by the performance of "dry runs" on all the operations allows productivity in line with the schedule right from the very start of overall construction work.
        • The dry runs covered all the operations: manufacture of the solar panels, quality control, administrative export processes, transport and customs clearance, unloading, storage, assembly…).These dry runs were carried out for each of the 3 manufacturers of selected panels allowing the installation of the first three complete one MW facilities in advance.
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