Eiffage Énergie Systèmes has been selected to design and build a building-based battery energy storage (BESS) plant in northern France
Partnering with Entech, our specialists have secured a major project to construct a battery energy storage plant and a dedicated high-voltage substation for an independent solar power developer. Bringing together a wide range of technical capabilities, the project will be delivered on a turnkey basis, with completion targeted for March 2027.
The scope also covers ongoing maintenance, which will be managed by our teams in close coordination with battery supplier Envision Energy.
Battery energy storage systems (BESS) are central to the evolution of modern power grids. In addition to smoothing renewable generation, they enable rapid grid support services requested by RTE, helping to maintain frequency, voltage, and overall system stability.
Eiffage Énergie Systèmes, through a dedicated joint venture established with its technology partner Entech, is delivering a comprehensive solution for large-scale battery energy storage systems (BESS). The scope of work covers the full lifecycle of the facilities, including design, detailed engineering, construction, and long-term operation and maintenance under extended contractual agreements. This integrated approach ensures both technical consistency and operational reliability throughout the project’s lifespan.
By combining the strengths of both organizations, the joint venture brings together extensive expertise in infrastructure development and advanced energy storage technologies. Eiffage Énergie Systèmes contributes its wide-ranging capabilities in civil engineering, electrical systems, and complex infrastructure delivery, while Entech focuses on energy storage system design and intelligent power plant control solutions. This collaboration enables the partners to address every technical aspect required for the successful deployment of modern BESS installations.
According to Jean-Marc Monzein, Director of the dedicated structure created to oversee these BESS projects, the collaboration within the Eiffage Group allows for a complete and seamless technical offering. The teams are able to manage civil works, structural foundations, mechanical systems, and electrical installations across high voltage (HV), medium voltage (MV), and low voltage (LV) levels. This includes AC and DC high-voltage equipment, electrical networks, switchgear, control panels, automation systems, and advanced supervision platforms. Entech, for its part, leads the design of the battery storage architecture and the intelligent systems that optimize plant performance and interaction with the power grid.
The facility itself is designed as a 50 MW battery energy storage power plant, capable of storing surplus electricity during periods when the transmission network operated by RTE is experiencing excess capacity. Once stored, this energy can be released back into the grid as required, with the plant capable of injecting up to 100 MWh of electricity once or twice per day. The system has been engineered for long-term performance, with an expected operational life of approximately fifteen years, supporting grid stability and flexibility over the long term.
From a technical standpoint, the power plant is structured around a modular and scalable configuration. It is composed of six identical and duplicable “islands,” each connected to a dedicated high-voltage substation. This modular design simplifies construction, facilitates maintenance, and allows for potential future expansion. Each island integrates four battery containers, each with a capacity of 5 MWh, along with two 40-foot medium-voltage station containers. This configuration ensures an efficient balance between energy storage density and operational accessibility.
The energy conversion process within the plant follows a carefully engineered sequence. Electricity stored in the batteries is initially in direct current (DC) form. This DC power is then converted into alternating current (AC) using power conversion systems. Following conversion, the electricity passes through 33 kV transformers, which step up the voltage to a level suitable for reinjection into the transmission network. Once transformed, the energy is fed back into the RTE grid, where it contributes to balancing supply and demand and enhancing overall grid resilience.
The project is being delivered under an Engineering, Procurement, and Construction (EPC) contract model, reflecting a compact and optimized technical solution. This approach minimizes interfaces between stakeholders, reduces project complexity, and supports cost efficiency while maintaining high performance and safety standards. In addition to the EPC scope, the contract also includes a comprehensive Operation and Maintenance (O&M) component. This long-term O&M service will be delivered jointly with Envision Energy, ensuring continuous monitoring, performance optimization, and reliable operation throughout the plant’s service life.
Overall, this project highlights the growing role of battery energy storage systems in modern power networks and demonstrates how strategic partnerships can successfully deliver complex, large-scale energy infrastructure solutions.
Source link: https://www.eiffage.com/
