Neoen: construction begins on a 248 MW BESS, the largest in France

Neoen is launching the construction of France's largest BESS (Battery Energy Storage System), with a capacity of 248 MW/496 MWh, the group announced on 02/04/2026.

This battery is to be installed on a 2.4 hectare site in Vernou-la-Celle-sur-Seine (Ile-de-France). It will be the first to be connected to RTE's 400 kV transmission grid. Construction work is scheduled to start in summer 2026. Commissioning is scheduled for 2028.

This battery will help to "provide the grid with frequency and voltage regulation services and will help to relieve congestion on the Île-de-France power grid, encouraging greater penetration of renewable energies in particular", says Neoen.

The group has signed a contract with the Japanese company Nidec, which will supply the battery packs. These parts will be assembled at its new production centre in La Fouillouse (Loire), near Saint-Étienne.

This is the second major storage project developed by Neoen in France. The independent power producer is also building a 92 MW battery at Pleyber-Christ (Finistère).

The group has a total portfolio of 2.2 GW under…