Envision Energy and Kallista Energy Deliver 386 MWh Energy Storage Project to Accelerate Future Energy System in France
Envision Energy has announced an expanded collaboration with European renewable energy producer Kallista Energy to develop the 193 MW / 386 MWh Neuilly-en-Thelle battery energy storage system (BESS) project in Hauts-de-France. Construction of the project began in early July 2026, with commercial operations anticipated to start before spring 2028.
The Neuilly-en-Thelle project follows the Saleux project, which was Envision Energy's first BESS initiative in France and broke ground in 2025. This new project represents a significant advancement in the partnership between the two companies and aims to serve as a scalable model for energy storage deployment throughout Europe, contributing to the Future Energy System in the region.
Envision Energy will implement its advanced BESS solution and manage the entire lifecycle of the project, including site maintenance and battery recycling after 25 years of operation. Utilizing lithium iron phosphate (LFP) cells from Envision AESC's 10 GWh gigafactory in Hauts-de-France, which has been operational since June 2025, the project emphasizes local battery manufacturing and system integration to bolster regional industrial capacity and improve energy infrastructure resilience. Once operational, the system is expected to provide important flexibility services to the French grid, such as frequency regulation through RTE's reserve markets, assisting in balancing electricity supply and demand.
The project is projected to have a capacity equivalent to the daily consumption of 30,000 households, which will enhance grid stability, allow for greater integration of renewable energy, and support France's ongoing electrification efforts.
Henry Peng, Senior Vice President of Envision Energy and President of EU & LATAM Regions, remarked, "Our second BESS project with Kallista Energy reflects the continued growth of a partnership built on shared ambitions for Europe's energy transition. Beyond delivering safe, reliable and scalable storage technology, Envision provides comprehensive lifecycle support, helping customers maximize long-term asset value." He added that this integrated approach furthers the Future Energy System, strengthening grid resilience and supporting sustainable industrial development across Europe.
Johann Tardy, CEO of Kallista Energy Group, stated, "Battery energy storage is a key driver to achieve electrification of energy consumption and massive expansion of renewable energies, which aim at reaching a low-carbon economy. For the battery energy storage system in Neuilly-en-Thelle, we are leveraging the strong collaboration built with Envision Energy on our previous project in Saleux to deliver a new high-quality storage infrastructure to further support the energy transition."