18.11.2025 | Intelligent technology for a stable power grid
Large battery storage systems: a key pillar of the energy transition
Large battery storage systems are a key component of a sustainable energy future. They store electricity, for example from solar or wind power, and feed the energy into the grid when it is needed. They also balance out fluctuations in the grid, thereby increasing security of supply. Against this backdrop, Axpo is investing in one of Switzerland's largest battery storage facilities, as well as several projects in neighbouring European countries.
Renewable energies such as wind and solar energy are weather-dependent – they do not always supply electricity when we need it. This is precisely where battery storage comes into play: it stores surplus energy when production is high and releases it again when demand increases. In this way, it helps to keep the electricity grid stable and use renewable energies efficiently. Axpo uses sophisticated software and algorithms to operate the storage systems as efficiently as possible. This means that electricity is fed into the grid or stored exactly when it makes the most economic and technical sense.
Electricity for thousands of households
Axpo is currently building one of Switzerland's largest battery storage facilities in Gurtnellen in the canton of Uri, with a capacity of 50 MW. The facility can store up to 100 MWh, which corresponds to the daily electricity needs of over 10,000 households. Commissioning is planned for the first half of 2026. ‘With this step, we are making an important contribution to the flexibility of energy supply and security of supply in Switzerland,’ says Frank Amend, Head of Batteries and Hybrid Systems at Axpo.
Projects under construction in France and Germany
In addition to the Swiss project and the large-scale battery storage facility already opened in Landskrona, Sweden, Axpo has begun construction on several other projects.
In France, a battery with a capacity of 60 MW and up to 120 MWh of storage capacity is being built in Orbec (Normandy). Civil engineering work for the construction of the associated substation with transformer – the battery will be connected directly to the high-voltage grid – has already begun. The battery is scheduled to go into operation in the first half of 2027. In Presles-en-Brie, east of Paris, a second project with a capacity of 11 MW is also being built, which will be connected to the medium-voltage grid of the distribution network operator Enedis.
Construction work is also beginning in Germany, namely in Bernburg in the federal state of Saxony-Anhalt. A battery with a capacity of 15 MW is being built here. Numerous other projects throughout Europe are also in the planning stages.
Five questions for Rafaela Tsaousi, business developer in Axpo's battery team
Question: Why are batteries relevant for the future energy system?
Answer: Europe and Switzerland have set themselves the goal of becoming climate neutral by 2050 and increasing the share of renewable energies. To achieve this, the electricity system needs to be more flexible. Batteries help to close the gap between fluctuating generation and consumption, support grid stability and promote the integration of renewable energies. Their modularity makes them suitable for a wide range of applications – from small systems to large supply projects.
Question: What are the challenges and opportunities for battery projects, specifically in Switzerland?
Answer: The Swiss energy market is currently difficult to predict and is changing rapidly. A possible electricity agreement with the EU could open up new opportunities, for example through greater market integration. However, it remains to be seen whether this will happen, which makes long-term planning difficult. Nevertheless, we at Axpo are investing specifically in battery storage, not least because of its contribution to security of supply and system stability.
Question: What are typical applications for battery systems?
Answer: Battery systems are used for frequency regulation and energy shifting, among other things. They thus serve to stabilise the electricity grid and therefore benefit grid operators, utility companies and end consumers. Their flexibility is particularly valuable in a decentralised energy system. Operation becomes complex when several services are provided simultaneously – this requires advanced optimisation algorithms and specialised personnel. Other potential applications, such as voltage maintenance and congestion management, are currently being discussed within the industry. However, these come with technical challenges, as batteries can only store a limited amount of energy.
Question: What factors are important when developing battery projects?
Answer: The location conditions and grid connection are crucial. Close cooperation with local authorities and communities is equally important. At Axpo, we take a proactive approach and contact the communities and relevant authorities at a very early stage of the project to ensure constructive cooperation.
Question: What are the main considerations for integrating the plant into its surroundings?
Answer: For us, safety and useful integration into the surroundings are paramount. Like any technology, batteries have specific technical requirements. A well-thought-out fire protection concept and suitable noise protection measures are particularly important. In addition, we attach great importance to visual integration that is as inconspicuous as possible – especially at locations where the plant could affect the townscape or the surrounding area.
