Harmony Energy has switched on a 100 MW/200 MWh battery energy storage system (BESS) at the port of Nantes-Saint-Nazaire. It is the largest BESS in France, with full operation expected by the end of 2025. August 22, 2025 Marie Beyer Image: Harmony Energy From ESS News UK-based renewables developer Harmony Energy recently switched on a BESS at the port of Nantes-Saint-Nazaire, France. With 100 MW of power output and 200 MWh of storage capacity, the facility is the largest of its kind in the count...