Bringing geothermal energy to life

Thuy PHAM, project manager at Tractebel, agreed to answer a few questions about her collaboration with ENGIE Solutions on the GeoMarne project.

What are Tractebel's missions in the GeoMarne project?

Tractebel is involved in this project as Prime Contractor to ENGIE Solutions for the construction of the GeoMarne production plant and heating network. Accustomed to working on major projects, Tractebel has drawn on the experience of CIMES Assistance to complement its skills in the field of heating networks.

The EMO service entrusted to our company covers several areas of this project. First of all, the design of the network, with the realisation of the thermo-hydraulic simulation required by our partner CIMES to produce plans for 19km of distribution network.

Concerning the power station, we are responsible for the design studies, assistance in the awarding of supply and works contracts, and site supervision until commissioning of the power station.

From the sketch study phase to the acceptance of the power plant, Tractebel is the preferred partner of ENGIE Solutions for the construction of this exemplary geothermal site.

Through this project, Tractebel, alongside ENGIE Solutions and the Paris-Vallée de la Marne Urban Community, is contributing to the objectives of developing renewable energies and combating climate change.

What is the role of engineering, and therefore of Tractebel, in this project?

Tractebel has been involved, and is still involved, in two stages in this project: firstly, we mobilised our engineering team to design the power plant and heating network. In the second stage, we provided our expertise to the project owner during the construction phase.

The first phase began with the production of a sketch, based on the feasibility study carried out by ENGIE Solutions. We confronted this with the constraints of the developer, the Paris-Vallée de la Marne Urban Community (architectural, environmental, safety, etc.) and the needs of the final operator.

On the basis of this sketch and the process solution initially selected, our teams intervened to optimise the equipment and operation of the power plant, in order to maximise the rate of renewable energy delivered, and to facilitate the steering and maintenance of the power plant during the operating phase.

All these stages seem very conceptual, how can the project be made more tangible?

Thanks to the technology, in the PRO (detailed studies) phase of the chosen solution, we were able to establish a 3D model of the power plant using REVIT. This 3D model allows us to install the equipment, model the piping routes, and cable tray passages, visualise the maintenance areas and identify possible constraints or conflicts between different items of equipment in order to adjust them... even before it comes out of the ground!

The control unit can thus be visualised by the various parties involved.

Thanks to this 3D model, we were able to do a design review with the ENGIE Solutions team. This review was organised in consultation with the operators, allowing adjustments to be integrated directly into the model to facilitate future maintenance operations.

Then... the "works" phase begins?

Indeed, based on the elements described above, we refined the project budget and drafted all the documents necessary to launch consultation of the companies. Several work packages were put together: Civil Engineering, Heat Pumps, Gas Boilers, Geothermal Exchangers, Fumbers, Mechanical Equipment and Piping and finally, EIA for "Electricity Instrument and Automation". This is when the second phase of our mission started.

Our expertise and knowledge of the markets were made available to ENGIE Solutions in the analysis of the offers and in the technical meetings organised to select the companies that would carry out the work. Once lots have been awarded, Tractebel will then manage and monitor the worksite.

From July, the company EIA will manage the commissioning of the power station and our process and automation experts will be present to assist them, for an effective start of the installation in autumn 2021.

Why is this assignment important in your career at Tractebel?

We are proud of the work we do. Despite the health crisis and thanks to our knowledge of the market, we have managed to keep to deadlines and establish figures in line with the feedback from companies.

On a more personal note, I am particularly pleased to be involved in a meaningful project that is fully in line with the energy transition approach of the Paris-Vallée de la Marne Conurbation Community. GeoMarne is, moreover, an exemplary project in terms of geothermal energy. It will provide 82% renewable energy, whereas conventional installations are generally around 60%! A nice professional challenge that Tractebel enabled me to take up.

"I am particularly pleased to be taking part in a meaningful project that is fully in line with the Paris-Vallée de la Marne Conurbation Community's energy transition approach. GeoMarne is, moreover, an exemplary project in terms of geothermal energy. A nice professional challenge that Tractebel enabled me to take up. " Thuy PHAM, project manager at Tractebel