Ukraine's largest battery energy storage system (BESS), a 200 MW/400 MWh installation spread across six sites that represents one of the biggest storage deployments in Eastern Europe, is now begining commissioning work.
The battery energy storage system project, valued at €140 million, consists of 698 Fluence Gridstack cubes distributed across locations with individual capacities ranging from 20 MW to 50 MW. The system is designed to provide 400 MWh of storage capacity, which the companies state is sufficient to power 600,000 Ukrainian homes for two hours. Bulgaria has an operational 124 MW / 496.2 MWh battery energy storage system, beating the coming Ukrainian installation on energy duration but falls short on power output.
Commercial operations are scheduled to begin in October 2025, coinciding with Ukraine's winter heating season when grid stability becomes critical. The storage systems will provide frequency regulation, power reserves, and balancing services to support the national grid operated by Ukrenergo.
The project represents the first major energy infrastructure development delivered since the US-Ukraine Economic Partnership Agreement was signed in April, announced at the Ukraine Recovery Conference in Rome.
War conditions have forced Fluence to implement remote commissioning procedures for the first time. "The remote commissioning approach we have introduced ensures continuity and operational efficiency amid travel restrictions and will also enable faster scaling of any future deployments," said Julian Nebreda, Fluence's CEO.
