Neoen Brings Grid-Forming Battery Online in Brittany for RTE Pilot

French developer Neoen has commissioned a 92 MW / 183 MWh battery storage facility in Brittany, its fourth operational storage site in France. The Breizh Big Battery, situated in the municipality of Plœber-Christ, will participate in a pilot programme led by transmission system operator RTE.

The test centres on grid-forming technology, which allows a battery to maintain voltage and frequency independently — unlike the more common grid-following mode, where batteries simply synchronise with the existing network signal. Grid-forming systems generate their own stable reference points, giving them the ability to hold a node steady when disruptions occur. RTE will examine whether the Breizh facility can demonstrate this capability following a software update, with no need to replace its power inverters.

The project took 18 months to build, with Huawei and Equans participating in construction. Neoen is also providing a community benefit: a rooftop solar installation on a sports hall in Plœber-Christ.

The commissioning coincides with Neoen pressing ahead on a larger domestic project — a 248 MW / 496 MWh installation in Vernou-la-Celle that will be the biggest battery storage facility in France. Across all markets, the company’s storage portfolio is growing to a combined 3.5 GW / 10.6 GWh.

Source: ESS News (pv magazine)