Envision Energy, a specialist in green technology, has deepened its collaboration with European renewable energy producer Kallista Energy to deliver the 193MW/386MWh Neuilly-en-Thelle battery energy storage system (BESS) project in Hauts-de-France. Construction began in July 2026, with commercial operation expected before spring 2028
Expanding on the Saleux project, Envision Energy’s first BESS project in France, Neuilly-en-Thelle is another advancement in the companies’ partnership and provides a scalable blueprint for energy storage deployment across Europe, while advancing the Future Energy System in the region.
Envision Energy will deliver its BESS solution and oversee the project’s entire lifecycle. Powered by Envision AESC’s lithium iron phosphate (LFP) cells and supported by the company’s 10GWh gigafactory in Hauts-de-France, the project combines local battery manufacturing with system integration to reinforce regional industrial capacity and energy infrastructure resilience.
The system is set to provide essential flexibility services to the French grid once it is operational, including frequency regulation through RTE’s reserve markets, balancing electricity supply and demand. With capacity equivalent to 30,000 households’ daily consumption, the project will improve grid stability, facilitate greater integration of renewable energy, and support France’s electrification.
Henry Peng, senior vice president, Envision Energy and president of EU & LATAM Regions, said, “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 maximise long-term asset value. This integrated approach further advances our Future Energy System, strengthening grid resilience, accelerating the integration of renewable energy and supporting sustainable industrial development across Europe.”
Johann Tardy, CEO, Kallista Energy Group, said, “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”.
