## A New Milestone for French Energy Storage TagEnergy has inaugurated a 240 MW / 480 MWh battery energy storage system (BESS) at Cernay-lès-Reims in northeastern France, making it the country's largest operational battery storage project. The facility was formally inaugurated on October 1, 2026, after roughly four months of commercial operation. ### Project Details Connected to transmission system operator RTE's 225 kV grid, the project comprises 140 Tesla Megapack battery containers spread across just over three hectares. French construction and engineering group Eiffage carried out the civil and electrical works, while Alsace-based engineering company Tewa Solar provided project management assistance from development through commissioning. According to TagEnergy, the facility fed 70.5 GWh back into the grid during its first four months of operation, completing 145 full charge-discharge cycles over 125 days. It entered operation after completing the simulations, tests and certifications required to provide frequency containment reserve, automatic frequency restoration reserve and voltage regulation services. ### Financing and Ownership A banking consortium comprising ABN AMRO, NORD/LB and Caisse d'Épargne CEPAC provided financing for the project. TagEnergy jointly owns the facility with Banque des Territoires, which acquired a 49% stake in 2025, leaving TagEnergy as the majority shareholder. The investment is the first under a three-year partnership aimed at financing several large-scale battery projects in France. TagEnergy CEO Franck Woitiez said the Cernay-lès-Reims project shows that large-scale electricity storage has become an industrial reality in France. The facility is roughly double the capacity of the previous largest operating French BESS, a 100 MW / 200 MWh plant near Nantes-Saint-Nazaire that began operating in August 2025. Source: pv magazine, TagEnergy press release This article was assisted by AI analysis. Please refer to the original source for official information.