Battery storage launched in Gueugnon

Verso Energy inaugurated its first battery storage system in Gueugnon, Saône-et-Loire, on October 6. This battery is paired with a floating solar power plant at Gravières de l'Arroux, a 23.1 MWc facility that became operational in July 2025 between Gueugnon and Rigny-sur-Arroux.

Technical details of the battery

The battery has a power capacity of 6 MW and 12 MWh, enough to supply electricity for two hours. Combined with the solar plant, the installation is described as the largest hybrid floating solar power plant in France. The total investment was about 27 million euros, with nearly 4 million euros allocated to the storage system.

Partnerships and construction

The batteries were supplied by Huawei, and the construction was handled by two local companies, CEME and Bouhet TP. The battery is designed to store surplus electricity produced during peak sunlight hours and re-inject it later when electricity sells better, until planned grid upgrades by Enedis on the source substation are completed by 2028.

Future use of the battery

Once the grid upgrades are complete, the battery will be used primarily to help maintain stable grid frequency, then for the capacity mechanism, and increasingly for buying and reselling electricity throughout the day. Verso Energy has also launched the construction of a second battery in Vésigneul-sur-Marne, in the Marne, which will have a capacity of 23 MW and 46 MWh, nearly four times more powerful than the Gueugnon battery.

Company strategy and control

The company has decided to retain control over the operation, with its own teams managing the batteries and selling stored electricity during periods of high demand or as services provided to the grid. Verso Energy's strategy extends beyond storage, aiming to become an energy company capable of aligning renewable production with consumption.

Current and future solar projects

The company already operates several ground-based solar power plants, including Aix-en-Provence (1.7 MWc, 2020), Roquefort in the Landes (4.7 MWc, 2022), and others in the Aude, Indre, and Loire-Atlantique regions. Additional solar projects are planned, including a 16 MWc power plant in Porcelette in Moselle in 2027, and two agrivoltaic projects in the Tarn.

Hydrogen and fuel projects

In terms of molecules such as hydrogen and fuels produced from electricity, the projects are changing scale. CarlHyng, in Carling in Moselle, plans to produce 300 MWe of hydrogen between 2027 and 2030. DEZiR, in Rouen, aims for 400 MWe for synthetic fuels by 2029. These plants will consume far more electricity than the entire solar power plants of the group, making their ability to modulate consumption according to grid needs crucial.