It is in Cernay-lès-Reims, in Marne, that the low-carbon energy specialist TagEnergy decided to install its battery storage platform. With a capacity of 240 MW and 480 MWh, the project includes the installation of 140 battery containers, capable of supplying nearly 20% of the residential needs of the inhabitants of Marne (half a million residents), according to the TagEnergy estimates. The investment made to launch this project is not communicated by the company.
Record storage capacity
“The Cernay-lès-Reims project is approximately five times larger, in terms of storage capacity, than the largest current project in France, located in the town of Saucats (Gironde),” says Christophe Léonard, associate director of the company. Based in Portugal, TagEnergy (60 employees; CA: NC), which raised 450 million euros in 2022, is controlled by TagEnergy SAS, a joint venture between the Impala SAS group, founded by Jacques Veyrat, and the company d investment Exor NV
Since its inception in 2019, TagEnergy has built a portfolio of over 6GW of solar, wind and battery storage technologies across the UK, Portugal, Spain, France, Italy and Australia, including 1.9GW are under construction or in operation. “TagEnergy is proud to announce this flagship project in France, just weeks after connecting the first phase of the southern hemisphere’s largest wind farm to the grid in Australia and the largest battery on the transmission network in the United Kingdom” , explains Franck Woitiez, CEO of TagEnergy, in a press release.
Operational at the end of 2025
Activities on the Marne site began in April 2024, with archaeological excavations carried out by the Urban Community of Grand Reims. Construction should now start in January 2025 and be spread over a period of twelve months, with a connection to the network planned for the end of 2025. “Job creation will mainly take place during the construction phase: around sixty FTEs (equivalent full time) will build this project Then, in the operational phase, the site will be operated remotely and will not require, apart from the upkeep of the greenery and maintenance, any permanent intervention”, supports Christophe. Leonard.
Concretely, the park will be made up of 140 containers 9 meters long, containing batteries but also inverters, which are equipment which transform the direct current from the batteries into alternating current. The containers will be connected to electrical transformers, allowing the voltage to be raised to the next level. Then, at the end of the chain, “in the immediate vicinity of the public electrical substation, there will be a private electrical substation at 225,000 volts”, describes Christophe Léonard.
Tesla as a partner
“These batteries are supplied by Tesla, which is the technological partner,” says Christophe Léonard. Tesla will integrate batteries into containers. “These are lithium iron phosphate (LFP) batteries, which are used in automobiles. LFP chemistry is less prone to thermal runaway, which is a considerable advantage given the number of batteries installed on the same site”, continues the associate director in France of TagEnergy.
More than a technical partner, Tesla is also the project manager. “They are the ones who will directly connect their batteries to the electricity network, and who will provide the services directly to RTE. This remains a project developed and managed by TagEnergy, but the market interface will be Tesla,” explains Christophe Léonard.
The choice of Marne
After a search for land carried out throughout France, TagEnergy settled on the town of Cernay-lès-Reims: in addition to being able to accommodate three hectares of energy storage project, the land chosen is located at proximity to an RTE public electrical substation with “very significant” connection capacity, according to the company. “On the other side of the project, there is the A34 motorway. It's interesting, because our wish is to limit the impact of our infrastructure, visually and soundly. We are here 400 meters from the houses the closest ones, in a fairly noisy environment, so it’s really very conducive to integrating there,” comments Christophe Léonard.
Christophe Léonard is the associate director in France of TagEnergy — Photo: Xavier-Alexandre Pons
No public assistance
The project was made possible thanks to a financial package supported by a banking consortium, bringing together the Dutch bank ABN AMRO, the German commercial bank NORD/LB and Caisse d'Épargne. In addition, the company has not received any public aid at this stage. “This is an interesting point of the project. We are convinced that the characteristics of the batteries will be able to bring value to the network in such a way that we will reimburse our investment,” anticipates the associate director of TagEnergy in France. At this stage, the company does not communicate on the estimated yields of the Marne site.
A growing market
“This is only the beginning of the adventure: we are only beginning to know how to store electricity on a large scale,” believes Christophe Léonard. In one of its reference scenarios, RTE indicates that 6 GW of batteries by 2030 could be necessary in order to achieve the level of reliability sought on the French network. “It is directly linked to the development of renewable energies,” continues the associate director of TagEnergy in France.
The TagEnergy project is in fact calibrated to respond to three functions of the French energy landscape: optimizing the use of carbon-free electricity production, providing critical capacity during periods of high demand, and strengthening the stability of the network, with a “time almost instantaneous response,” according to the company. “The trajectory defined in the Multi-year Energy Program, currently in public consultation, provides for a multiplication of capacity by 2.5 for wind power and by 4 for solar by 2035. This major transformation must be be accompanied by a significant development of flexibility solutions, alongside demand flexibility, battery storage is emerging as a pillar of this transition,” adds Christophe Léonard.
