Cheviré will have the largest battery energy storage capacity in France, utilising Tesla Megapack technology, with a total power of 100 MW / 200 MWh. It will be able to charge and discharge the equivalent of 2 hours of electricity, enough to power 170,000 homes – more than the population of the city of Nantes. These will be the first batteries of such capacity ever installed in France.
Located in the port of Nantes Saint-Nazaire, on the site of the former Cheviré fossil fuel power plant, which operated from 1954 to 1986 and was powered by coal, gas, and oil, Cheviré BESS will be a milestone in France’s energy transition.
Battery energy storage is now a crucial component in the strategy for deploying renewable energy.
Andy Symonds, CEO of Harmony Energy France, said: “This is not only a notable achievement for Harmony Energy, but the project also marks a significant milestone for the French energy system. It is the first battery storage installation of this scale in France.
“Battery energy storage installations will be necessary throughout France to provide essential services and support the rapid evolution of the energy landscape. They will facilitate electrification, the integration of renewable energy, the security of our supply, and help control costs for both the network and the customer. If we want to replace fossil fuels with renewable energy, we must also integrate flexibility into the system in order to maintain grid stability and ensure a continuous supply of electricity. This is exactly what this project will achieve by continuously balancing supply and demand. We look forward to commissioning this energy park next year, the first of a series of projects we plan to deliver on French soil.”
The Cheviré Storage Park: 364,000 Tons of CO2 Equivalent Avoided Over 20 Years
Located on the left bank of the Loire, downstream from Nantes, the Cheviré fossil fuel power plant was operated by Électricité de France (EDF) from 1954 to 1986. Fuelled by coal and oil, transported by pipeline, and later by natural gas starting in 1958, the plant consumed hundreds of thousands of cubic metres of Lacq gas annually.
Clément Girard, Director of Operations, said: “Located precisely on the site previously occupied by a fossil fuel power plant, the 100 MW battery system will have the capacity to store the equivalent of the electricity needs of approximately 400,000 people for 2 hours. Thus, starting from a site historically associated with high CO2 emissions, the delivery of the Cheviré BESS will transform the site into exactly the opposite, avoiding nearly 364,000 tons of CO2 equivalent over 20 years – equivalent to the carbon footprint of 41,000 people each year.”
To date, approximately 1 GWh of battery storage capacity is operational in France. The completion of the Cheviré BESS will represent a 20% increase in installed energy capacity. To support the deployment of renewable energy production in France, the French grid operator RTE anticipates total storage capacity in the range of 12 to 15 GW by 2050.
It is also worth noting that large multi-megawatt storage parks do not pose a significant threat in terms of land consumption. With very high energy density relative to their land footprint, only about 150 hectares of land would be needed to meet national targets by 2050. Thanks to a design that minimises the project’s footprint, the Cheviré BESS will cover the equivalent energy needs of the city of Nantes on an area of just 1.3 hectares.
Electricity Storage: A Less Carbon-Intensive, More Reliable, and Competitive Energy System
Battery storage technology has been used on a small scale in France for around 10 years. Thanks to its ability to absorb and release electricity on demand, battery energy storage now offers collective benefits to the national electrical grid. It helps stabilise the grid managed by the transmission system operator, RTE, preventing forced disconnection of certain users in case of instability or lack of supply. It also allows real-time adjustment of the balance between production and consumption by injecting energy into the grid when demand peaks.
Furthermore, battery storage contributes to stabilising electricity prices by reducing the need for fossil fuels and shifting excess energy production to periods of peak demand. This reduces the carbon footprint of the electrical grid and helps achieve national energy independence by minimising reliance on fossil fuels.
Clément Girard added: “For the electrical grid to function, there must always be a perfect balance between consumption and production on a national scale. Historically, thermal and hydroelectric power plants have played this balancing role. Batteries are intended to replace the most CO2-emitting plants while positively impacting electricity prices. The Cheviré storage park will provide regulation services to the Electricity Transmission Network (RTE) on a second-by-second basis and facilitate the integration of renewable energies by ‘shifting’ excess production to meet peaks in consumption. As RTE highlights in its own studies, the need for storage will only grow due to the electrification of energy use and the expansion of solar and wind power. Battery storage will be essential in ensuring the reliability and decarbonisation of the grid, while also avoiding high price volatility.”
Currently, France balances its grid during peak periods using fossil fuels, particularly gas. Since the war in Ukraine, France has reduced its reliance on Russian gas, instead importing large quantities of so-called “natural” gas, mostly shale gas from the United States. However, such fracking projects are banned in France due to their environmental and health impacts. The development of battery storage parks like Cheviré BESS will help reduce the environmental footprint of the French energy system.
Image credit: Parc de Cheviré photomontage by Yann Bay Architectes
