France’s register names 908 batteries in service, 2,245 MW. That is up by 723 MW since the end of 2025, and RTE’s grid has almost no room left for more.

The register has grown from 145 MW at the end of 2021 to 2,245 MW

Each bar is one published edition of the register, counting only the batteries in it. A battery enters the register when its network operator files it, which happens at connection, so a bar counts what was connected and filed by that date.

Registre national des installations de production et de stockage d’électricité, ODRÉ, Licence Ouverte 2.0: every edition from the end of 2019, the rows filed as storage whose technology is battery. The register is published about every two months now, some six weeks after its date. What changed between editions.

Most of France’s batteries are small: 857 of 908 are between 1 and 5 MW

The fleet has two shapes. A few dozen large batteries sit on the transmission grid, and the five largest hold 592 MW between them. Beneath them are hundreds of batteries of a few megawatts on the distribution grids.

694 of France’s 908 batteries are filed under one family of names, NWJ, and most are the same 1.2 MW unit

The register files 694 batteries, 883 MW, under names beginning NWJ, almost all of them NWJ MET followed by a number or a place. That is 76% of France’s batteries by count and 39% by power. 605 of them are 1.2 MW, and every one connects to Enedis’s medium voltage grid. 204 entered service in 2025, against 91 in 2024, twice as many, and 130 so far in 2026. Until the register of 31 August 2026 most of them were filed with their names withheld: that edition published 564 names the edition of 31 December 2025 had withheld, 558 of them NWJ. The national company register gives NW JOULES as président of all four NWJ companies asked about so far (NWJ MET, NWJ MET 2, NWJ MET 3, NWJ MET4), which hold 132 of these batteries. Who holds the shares is not public.

Batteries whose name in the register begins NWJ, by the year of their date of entry into service. The last bar is this year to the register’s date.

The register’s own power figure for each battery. The register also files 14 storage installations of 51 MW whose technology is not battery or is not stated; they are not counted on this page.

Where the batteries are

One circle per battery, sized by power. Every one is in service: the darker circles are on RTE’s transmission grid, the rest on a distribution grid.

908 of 908 batteries placed: 833 at the distribution substation they connect through, at the position Caparéseau publishes for it; the rest near RTE’s substation in their commune or at the commune’s centre. Each battery’s page says which.

29 batteries of 10 MW and more, 20 of them on RTE’s transmission grid

The register names the batteries RTE connects by RTE’s own code for the site, so the largest, at Saint-Laid near Reims, appears as RTE’s storage site at Saint-Laid in Cernay-lès-Reims. The register gives no owner; who built and owns each one is for the owners’ own releases, which this page does not yet read.

The companies behind 137 of the batteries, from the company register

The national register names a battery, not its owner. Where a battery’s name is a company’s name exactly, the French company register (recherche-entreprises, from INSEE’s Sirene and the national companies register) gives that company and the companies that run it. Nothing is joined on a near match, so the batteries named after a site rather than a company are not here.

Every company, with its batteries. The company register as read by the government’s search service, recherche-entreprises.api.gouv.fr, under Licence Ouverte.

Every one of RTE’s 2,741 substations has less than 5 MW of room for a new battery

RTE, the French transmission system operator, publishes a map called Cartostock showing how much battery capacity each of its substations could connect without restrictions. On the read of 20 October 2026, every substation showed less than 5 MW, and every one was flagged as facing competing requests: in RTE’s definition, more than three battery requests nearby asking for more than three times the room there is.

The only room left is in ten zones where RTE offers 1,065 MW in all to batteries that accept limits on when they may run. RTE calls these offers “gabarit” connections, and every one on the map today is a limit on export: a battery there accepts set hours in which it may not put power onto the grid.

RTE, Cartostock (cartostock.cloud-rte-france.com), read 20 October 2026. RTE publishes the substations’ positions only approximately, for security, and gives the data no date of its own, so it is saved whenever it changes and the date here is the date we read it. Cartostock covers the transmission grid only; the distribution operators publish no equivalent for batteries.

Batteries hold 1,135 MW of certified capacity for 2026, against 2,245 MW in the register

France pays for firm capacity through its capacity mechanism, and every unit taking part is certified for the capacity RTE judges it can be relied on to deliver at peak. That certified figure is well below a battery’s power, because a battery holds only a few hours of energy. RTE publishes the register of certified capacity, but it names a unit only when its certified capacity is 100 MW or more; every smaller unit is counted only in its kind’s total.

One battery unit is named: AOLT_CXI20C9001, 114 MW, held by TOTAL FLEX. Who holds the rest, and where, RTE does not publish.

RTE, Registre des capacités certifiées, read 20 October 2026, the updated certified capacity. A battery unit in the mechanism can be several sites grouped by one holder.

What is not here, and why

A meter on any battery, because no French body publishes one: RTE’s output by unit covers no storage, and ENTSO-E carries French batteries only as one national total. Any instruction RTE gives a battery, because RTE publishes its balancing actions only as national totals. An owner, because the register carries none. A connection queue, because neither RTE nor the distribution operators publish one battery by battery; Cartostock’s room by substation is the nearest thing. The names of 149 batteries, 319 MW, which the distribution operators file as confidential. Prices: the French day-ahead price is on the European prices page. Nothing on this page is modelled.

Sources: Registre national des installations de production et de stockage d’électricité, on ODRÉ (Open Data Réseaux Énergies), Licence Ouverte 2.0. RTE, Cartostock and the Registre des capacités certifiées. Caparéseau (RTE and the distribution operators) for substation positions. geo.api.gouv.fr for communes. recherche-entreprises.api.gouv.fr for companies.