Biomass chips after silo entry and cleaning © Bertrand Bechard

Renewable energies for energy performance

Along with reducing resource requirements, renewable energies provide the most promising answer to the announced depletion of fossil energy and the need for concrete moves towards a post-carbon society. The Group's divisions design and produce cutting-edge technical solutions in these areas.


panneaux solairesInstallation of photovoltaic solar panels on the Cestas solar farm ©Eiffage Energie

The Energy division companies are experts in solar energy, from studies through to cabling and maintenance. They develop optimised, bespoke solutions for both private and public facilities in France and abroad.

Europe's largest photovoltaic solar plant featuring a million photovoltaic modules is currently in service in Cestas (South-West France). The project led by Clemessy relied greatly on the complementary know-how of Clemessy, Eiffage Énergie and the Infrastructures division. The 250 hectare farm is now in operation and produces 350 GWh/year (equivalent to the domestic consumption of the city of Bordeaux) directly injected into the RTE high-voltage grid. The teams from Clemessy will be in charge of operation and maintenance for several years to ensure the facility functions correctly.

Quilapilún Solar Plant ©Eiffage Energie

The Chilean subsidiary of Eiffage Energia won the contract for the construction of Quilapilún solar plant near Santiago. Once completed in 2016, the plant will be one of the country's largest, deploying 350,000 photovoltaic modules (110 MWc). Eiffage Energia takes charge of the civil engineering work, material supplies and the installation and electromechanical assembly of the panels, confirming its expertise in this field. And as a result, the teams will have contributed to almost a third of the country's photovoltaic facilities.

Kari, the Korean space centre, has appealed to the expertise of Clemessy Switzerland for two solar panel simulators under various space programmes, to validate the entire electric architecture of satellites.


Eiffage Energie Tertiaire Nord completed the extension of the experimental photovoltaic platform in Loos-en-Gohelle (Pas-de-Calais). This infrastructure was designed to test and analyse all sorts of modules and batteries used in solar farm construction to identify combinations that deliver optimum output. Thanks to internally developed instrumentation, technical data about the facility can be presented during educational tours.  

geyser geothermie
Geyser in Iceland – Photo competition 2012 © Michel Ballet (Eiffage Construction)

Geothermy and thermal sea power


In Nancy, the Infrastructures, Energy and Construction divisions completed France's biggest ground-coupled heat exchanger in challenging conditions (depth of earthwork and heavy traffic).

Another project, the "Cologen" PPP contract led by Eiffage Construction, will be implementing the principle of geocooling or ground-coupled heat exchanger. It will use the ground's thermal inertia to cool (or heat) the buildings of the future secondary school in Carces.

Lastly, Eiffage Infrastructuras is testing geothermy as part of the smart predictive heating system of the PAVIREX roadway (more details in the chapter on innovation).


A new challenge for Clemessy

Clemessy has joined the "Geodeep" cluster, created in 2014, with the aim of developing its geothermy projects. Twelve companies from the French energy industry and two trade associations -AFPG and SER- work to develop renewable energy solutions that produce geothermal heat and power.


smartseille see water loop

boucle eau de mer

© Sea water loop - Picture from the smartseille eco-district interactive demonstrator ©Eiffage-Enodo


Energy solidarity was a structuring factor in the design of the Smartseille eco-district which gave rise to a number of innovations, including the sea water loop. The fruit of a partnership between Eiffage and EDF Optimal Solutions, the innovation involves building a warm water network using sea water as the source of balance. The water will be drawn from a mean sea depth in the harbour basins without disturbing operations at the Grand Port Maritime de Marseille, or the local natural conditions. Thanks to this system, renewable local energies will represent a 70% contribution to the heating and air-conditioning of the district's buildings which will also be linked up via a network of pipes to create heat exchanges between them. All air-conditioning and heating requirements will primarily use excess heat or cold produced by neighbours: surface area distribution between office space and housing achieves the balance.


Eiffage Métal has over 45 years' experience building offshore oil rigs that it has been using in the field of renewable maritime energies for several years. In 2014, the activities of Smulders and Eiffel Iberica confirmed the division's leading role in the offshore wind farm market, accounting for 70% of Smulders' annual revenues thanks to its involvement in large-scale projects deployed through to 2016.

In 2015, the Eiffage Génie Civil teams in Le Havre completed an innovative gravity-base foundation made of traditional concrete crowned with a metal mast, produced by a Smulders group entity. The foundation is towable by a conventional vessel and will serve for tests for the future wind farm in Fécamp.


© Eiffage Génie civil

Eiffage Énergie is more active in the onshore wind market, as illustrated below:

  • In the South-West region of France, in recent years the Infrastructures department has been partnering with Eole-Res, a developer, builder and operator of renewable energy production plants in Mediterranean and Middle-Eastern countries. The teams bury medium-voltage power cables between turbines, connect them to the ERDF stations, and create the farms' fibre optic network.
  • In Spain, the renewable energies department of Eiffage Energia performed the electromechanical assembly of four V100-type 2MW turbines for the Tarzy wind farm in Les Ardennes.
  • In 2016, Eiffage Energie Maine Bretagne (agent) and the Infrastructures division are building a farm of four 2 MW turbines in Séverac (Loire-Atlantique). This is an original project as it is largely financed by residents living near the site.
  • Eiffage Energia Chile is working on the wind farm of Sierra Gorda este, in the Antofagasta region, and Eiffel Iberica is building 33 masts in Mexico.
© Dupont Photographe

Energy production by cogeneration, biomass or biogas

Biomass heating and cogeneration are attractive energy solutions that the teams at Eiffage Énergie fully master, from design to maintenance. Since its creation in 2004, Eiffage Énergie Aquitaine's production department has worked on more than forty cogeneration plants. Another twenty have recently been delivered and around sixty are under study for three major market gardeners, Rougeline, Saveol and UCPT. Two types of equipment are proposed: gas plants producing between 2 and 4.5MW of heat and electricity, or power plants associated with biogas facilities (500 kW to 2 MW).

For example, the Paimpol cogeneration plant (Côtes d’Armor) is equipped with a 4.5 MWe gas engine producing electricity sold to EDF. A water and exchanger network converts exhaust gases to heat three greenhouses each spanning three hectares. A project for a second cogeneration plant on the same site is under study.

Eiffage Construction is building the carcass of these plants and particularly the fourth-largest plant located in the Côtes d’Armor department.

A biomethanisation unit (306 kW) has also been built on the organic farming site in Larrère (Landes) and will produce the equivalent of electrical power necessary for 410 homes and heat for 265. Teams from the industry business line of Eiffage Énergie Aquitaine have deployed the entire installation including electrical equipment, the grinder feed system and the methanisation tanks.

Biomass cogeneration plant ©Bertrand Béchard

Other divisions in the Group contribute to the construction of boiler plants and biogas facilities. Eiffage Construction has taken part in the construction of several biomass boiler plants like the one in Chambéry, a fully prefabricated structure supplied with local wood since winter 2014.

In the Champagne-Ardennes region, establishments of the Infrastructures division contribute to the construction of biogas and biogas purification facilities for local farmers, particularly for silage platforms used to store and ferment grain. After transformation and purification, the biomethane produced by the process can be injected into the natural gas networks of GrDF or GRTgaz.


Residual energy recovery made possible

In 2015, Eiffage built several facilities to recover residual energy from processes or equipment.

As an example, heating of the Agora sunspace at the GreEn-ER school in Grenoble (Isère) is provided by heat released by the server room (for hot air) and the cold rooms (to supply the heating floor). Similarly, the Pierre Berger Campus in Vélizy Villacoublay (Yvelines) is also heated thanks to heat produced by cold rooms, food service and servers, covering an estimated 60 to 70% of requirements.

GreEn-ER innovation and research centre Grenoble Eiffage ©Régis Bouchu - Actophoto