05.01.2026

Eiffage Énergie Systèmes builds an energy storage facility (BESS) in northern France

Our experts, in partnership with Entech, have won a tender to build a storage facility and associated HV substation for an independent solar energy producer. A whole galaxy of expertise has been developed to bring this project to fruition, with turnkey delivery scheduled for the end of March 2027. The contract also includes a maintenance component, which is the responsibility of our specialists, in partnership with battery supplier Envision Energy.

Battery energy storage systems (BESS) play a key role in the transformation of electricity grids. As well as managing intermittency, they can be called on at any time by power grid operator RTE to perform frequency system services, thereby ensuring that frequency, voltage and, more generally, electricity grid stability are maintained. 

Eiffage Énergie Systèmes handles facility design, engineering and construction via a joint venture with partner Entech, as well as the maintenance and operation of these units under long-term contracts.

“Our Branch and the Eiffage Group's combined expertise enables us to cover all the technical requirements for this type of installation: civil engineering, roadworks, mechanical engineering, high and medium-voltage equipment, HV current (AC and DC), LV current, networks, switchboards, automation and monitoring, while Entech is responsible for energy storage design and intelligent power plant control," said Jean-Marc Monzein, head of the unit set up for these BESS projects.

The facility consists of a 50 MW BESS plant capable of storing electrical energy when the RTE grid has excess capacity and feeding up to 100 MWh back into the grid once or twice a day for around 15 years.

"The power station consists of six duplicable islands connected to an associated HV substation. Each of these islands comprises four 5 MWh battery containers and two 40-foot Medium Voltage Station (MVS) containers. The energy stored in the batteries passes through power converters (DC/AC) and then 33 kV transformers before being fed back into the RTE grid," explained Jean-Marc Monzein.

This project, based on a compact technical solution, a reduced interface and cost optimization, is being carried out under an Engineering Procurement and Construction (EPC) contract. It includes an O&M (operation and maintenance) component, which will be provided in consortium with Envision Energy.

Eiffage Énergie Systèmes
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