Envision Energy and European renewable energy producer Kallista Energy have commenced construction of the 193 MW/386 MWh Neuilly-en-Thelle Battery Energy Storage System (BESS) in the Hauts-de-France region, marking the latest milestone in their partnership to strengthen grid flexibility and support Europe’s energy transition.
Construction of the project began in early July 2026, with commercial operations scheduled to commence before spring 2028.
The Neuilly-en-Thelle project builds on the companies’ earlier collaboration on the Saleux BESS project, Envision Energy’s first battery storage project in France, which broke ground in 2025. The new project is expected to serve as a scalable model for battery energy storage deployment across Europe while supporting the development of a more resilient and flexible energy system.
Under the agreement, Envision Energy will supply its battery energy storage solution and manage the project’s full lifecycle, including operation, maintenance, and battery recycling after its planned 25-year operating life. The system will utilize lithium iron phosphate (LFP) battery cells manufactured by Envision AESC, supported by the company’s 10 GWh battery gigafactory in Hauts-de-France, which has been operational since June 2025.
Once commissioned, the battery storage system will provide flexibility services to the French electricity grid, including frequency regulation through RTE’s reserve markets, helping balance electricity supply and demand. The project will have sufficient storage capacity to meet the equivalent of the daily electricity consumption of approximately 30,000 households, supporting greater renewable energy integration and enhancing grid stability.
Henry Peng, Senior Vice President of Envision Energy and President of the company’s Europe and Latin America regions, said the second BESS project with Kallista Energy reflects the continued expansion of a partnership focused on accelerating Europe’s energy transition. He added that Envision’s integrated approach, combining battery technology with lifecycle services, aims to maximize long-term asset value while strengthening grid resilience and supporting sustainable industrial development.
Johann Tardy, CEO of Kallista Energy Group, said battery energy storage is essential for accelerating electrification and expanding renewable energy deployment. He noted that the companies are leveraging the experience gained from the Saleux project to deliver another large-scale energy storage facility that will support France’s low-carbon energy transition.
Subscribe to get the latest posts sent to your email.











