Alpiq acquires France's largest battery storage facility

Lausanne – Alpiq is consistently pursuing its growth strategy in the area of flexible assets: the Swiss energy company has acquired the Cheviré operational battery storage facility in the port of Nantes Saint-Nazaire (France) from Harmony Energy, a leading European developer of battery energy storage systems (BESS). With an output of 100 megawatts (MW) and a capacity of 200 megawatt hours (MWh), it is currently the largest battery storage facility in the country. The facility in western France was inaugurated in December 2025 and can provide ancillary services for the national electricity grid or cover the electricity needs of 170,000 households for two hours.

With the acquisition of the Cheviré operational battery storage facility in the port of Nantes Saint-Nazaire in France on 21.01.2026, Alpiq is once again underlining its commitment to better integrating the rapidly growing production of electricity from renewable energy sources into the energy system, thereby contributing to a sustainable energy future. Battery storage facilities and other flexible assets, such as pumped storage hydropower plants, are indispensable for balancing the volatility of electricity production from wind and solar energy and stabilising grid frequency within a fraction of a second.

“The acquisition of the Cheviré battery storage facility marks a milestone in the implementation of our growth strategy in the area of flexible plants and for ensuring a sustainable, secure energy supply,” says Amédée Murisier, Head of Business Division Assets and member of the Alpiq Executive Board. “Flexibility is key to integrating renewable energy and ensuring the stability of electricity grids. We are investing specifically in flexible power plants and storage facilities that help strengthen security of supply and deliver sustainable solutions for our customers. France is a strategic market in this regard, and Cheviré represents a milestone on our path to strengthening and further expanding our position as a provider of flexibility solutions in Europe.”

Electricity for 170,000 households for two hours

In terms of installed capacity (100 MW) and storage capacity (200 MWh), the Cheviré BESS is currently the largest battery storage facility in operation in France and in Alpiq’s portfolio of operating BESS assets. It is an important element in the country’s security of electricity supply and a powerful symbol of the energy transition. The battery storage facility is located on the site of the former Cheviré fossil-fuel power plant, which was operated using coal, gas and oil from 1954 to 1986. The BESS can use stored electricity, mainly from climate-friendly production, to provide important ancillary services for the national electricity grid. If required, it can also supply 170,000 households – more than the entire city of Nantes – with electricity for two hours.

The Cheviré BESS was developed and commissioned by Harmony Energy, a leading European developer of energy storage projects. Harmony Energy was founded in the United Kingdom in 2010, followed by the establishment of its subsidiary, Harmony Energy France, in early 2022 to implement storage projects in France.

Alpiq expands secured BESS portfolio beyond 750 MW

With the acquisition of the Cheviré battery storage facility, Alpiq is strengthening its leading position in the field of flexible assets. This represents another milestone in the implementation of Alpiq’s growth strategy and in the dynamic expansion of its BESS portfolio.

Cheviré is Alpiq’s second asset in France. A further 100 MW BESS facility (in La Corne-en-Vexin) is currently under construction and will be operational in 2027. Overall, Alpiq has secured a BESS portfolio of more than 750 MW in France, Germany and the Nordics, with nearly half of it operational or under construction. Alpiq is also planning further investments in BESS and other flexible plants and storage systems in key geographical markets across Europe. As a result, Alpiq’s BESS portfolio is set to grow to multiple gigawatts of installed capacity over the next few years.

Alpiq plays a pioneering role in the integration of renewable energy in France

As a leading electricity producer and energy service provider with Swiss roots, Alpiq operates in many European countries, including France, where Alpiq has developed into one of the leading electricity and gas suppliers since 2002.

In 2025, Alpiq supplied more than 25 TWh of energy to customers in France and purchased around 5 TWh of electricity, most of which was generated from renewable sources. For the ninth consecutive year, Alpiq was once again voted the best electricity and gas supplier by industrial customers in France. Alpiq contributes to security of supply and offers French electricity consumers and producers market access and flexibility solutions. As an intermediary, it bundles and markets electricity from decentralised production facilities with a total installed capacity of around 2,000 MW. In this way, Alpiq is playing a leading role in the integration of renewable energy, a role it is further expanding in France through the acquisition of Cheviré BESS and the strategic partnership agreement signed by Alpiq and Vialis at the beginning of December 2025 for the development of the Lac Blanc / Lac Noir hydropower project in the Vosges.

Further information about Alpiq can be found at www.alpiq.com.