240MW/480MWh Cernay–lès-Reims project enters commercial operations as France accelerates battery storage deployment 

TagEnergy has officially switched on trading at its 240MW/480MWh Cernay‑lès‑Reims Battery Energy Storage System (BESS), propelling the project into France’s electricity market as the nation’s largest operational battery storage facility. 

Located in the Marne region of Grand Est, the landmark project is more than double the size of France’s next biggest operational BESS – a leap that cements TagEnergy’s position at the forefront of Europe’s accelerating energy storage revolution. 

The milestone marks TagEnergy’s first operational asset in France and signals the company’s long‑term commitment to the French energy storage market. 

The asset is co-owned by the Banque des Territoires, which actively supports the scaling of BESS infrastructures in France. 

TagEnergy CEO, Franck Woitiez, said the launch of commercial operations at the Cernay BESS represents a defining moment for the company’s European expansion. 

“As renewable generation continues to grow, battery storage is becoming indispensable to France’s evolving energy system,” Mr Woitiez said.  

“Bringing the Cernay BESS into trading not only establishes our first operational asset in France, it also reinforces our long‑term commitment to delivering the energy storage projects the country needs.” 

France is targeting 40 per cent renewable electricity generation by 2030 and carbon neutrality by 2050. With renewables currently supplying around 27 per cent of the nation’s electricity, large‑scale storage is emerging as critical infrastructure. France’s latest energy roadmap, PPE3, formally recognises storage as essential to grid flexibility and system stability. 

The country’s storage sector has surged from less than 50MW of installed capacity five years ago to around 1.5GW in early 2026. Projects like the Cernay BESS signal the next wave of utility‑scale deployment needed to support a cleaner, more resilient energy system. 

TagEnergy Managing Partner – France, Christophe Léonard, said the rapid rise of renewable generation is driving strong demand for large‑scale storage solutions. 

“As renewable output grows, the grid is seeing more periods of excess generation and sharper price swings,” Mr Léonard said. “Battery storage provides the flexibility needed to manage negative pricing events, integrate more renewable energy and reduce reliance on gas peaking plants.” 

Banque des Territoires, Deputy Head of Infrastructure Investment, Elise Stoffaes said this project delivers a valuable upgrade to power grid flexibility. 

“This commissioning marks a key milestone in our partnership with TagEnergy. It brings a large-scale storage asset online, securing the grid and strengthening renewable energy integration. This project perfectly demonstrates our strategic commitment to flexibility solutions.” 

The Cernay-lès-Reims BESS was delivered with Tesla Megapack technology, in partnership with transmission system operator and grid connection partner RTE, operational control partner SICAE, and local stakeholders including the Municipality of Cernay-lès-Reims and the Grand Reims metropolitan area.