eclanché SA, one of the world’s leading energy storage companies, has together with S4 Energy, has completed and handed over an innovative hybrid energy storage project for energy management provider S4 Ancillary Services in Almelo, The Netherlands. The project is an extension of an earlier pilot system created by Leclanché and S4 Energy. The overall system, now in operation, is a combination of Leclanché lithium-ion battery storage technology coupled with S4 Energy‘s flywheel storage to provide primary control power for frequency stabilization to TenneT, the local transmission grid operator. The combination with the fast-responsive flywheels reduces the energy throughput and amount of cycles of the Li-ion batteries and ensures an improved usage profile and longer system lifetime. Leclanché’s scope of supply and services in this project was the turnkey delivery of the battery energy storage system (BESS), the battery inverters and the energy management system (EMS) for monitoring and control of the battery system.