Harmony Energy has energised France’s largest battery energy storage system (BESS), marking a major step in the country’s renewable energy transition.
The Cheviré battery, located in the port of Nantes Saint-Nazaire Harbour, has a capacity of 100MW/200MWh and is believed to be France’s first large-scale, two-hour duration battery storage facility.
The site, formerly home to the Cheviré fossil fuel power plant, operated between 1954 and 1986 using coal, gas and oil – its transformation into a renewable energy hub represents a significant shift from fossil fuels to clean energy solutions.
Situated next to the national grid operator’s substation, the project is designed to deliver critical balancing services to the grid.
Powered by Tesla’s Megapack and Autobidder technology, the system can supply electricity to around 170,000 homes for two hours – more than the population of Nantes. It will help replace fossil fuel peaking plants, strengthen grid resilience, reduce carbon emissions and stabilise energy prices.
Andy Symonds, CEO of Harmony Energy France, said: “The Cheviré battery project is a landmark achievement for the wider energy transition in France. It shows how disused industrial sites can be repurposed to enable a more sustainable electrification of our power systems. This project strengthens energy security, supports affordability and helps pave the way for a cleaner, energy system which is less reliant on burning fossil fuels.
“We began construction on site in summer 2024 and have just achieved energisation, one year later, showcasing how expertise, skill and productive collaboration between teams working on a shared goal can accelerate the transition to net zero.”
