Alpiq has acquired the 100MW/200MWh Cheviré battery storage facility in the port of Nantes Saint-Nazaire from Harmony Energy.
The company said the asset, inaugurated in December 2025, is currently the largest operational BESS in France and can meet the electricity needs of 170,000 households for two hours.
It added that the deal underscores its strategy to integrate growing renewable generation into the energy system.
Amédée Murisier, head of business division assets at Alpiq, said: “The acquisition of the Cheviré battery storage facility marks a milestone in the implementation of our growth strategy in the area of flexible plants and for ensuring a sustainable, secure energy supply.”
He added: “Flexibility is key to integrating renewable energy and ensuring the stability of electricity grids.”
The Cheviré unit sits on the former site of a fossil-fuel power plant and provides ancillary services to the French grid.
Alpiq stated that the project is its second asset in France, alongside a 100MW BESS under construction in La Corne-en-Vexin for 2027.
It added that its secured BESS portfolio now exceeds 750MW across France, Germany and the Nordics with further investments planned.