Utility and power firms Axpo and energieUri have commissioned two large-scale battery energy storage system (BESS) projects in Gurtnellen, Canton Uri.
Announced 9 September, the projects, located at the same industrial site in the Plattischachen area, with Axpo’s installation rated at 50MW and energieUri’s at 8.4MW, were officially inaugurated marking what is currently Switzerland’s largest operational BESS facility.
The facilities are positioned adjacent to an existing national grid substation and energieUri’s Arniberg power plant. According to Hermann Epp, Member of the Cantonal Government and Director of Public Works, the Plattischachen industrial area is developing into an energy hub of national significance.
Axpo’s system is designed to serve national grid needs, while energieUri’s installation targets regional requirements within Canton Uri. Both projects aim to provide grid flexibility by storing surplus renewable energy and dispatching it during periods of high demand.
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System integrator Fluence supplied the BESS technology for both projects. Axpo’s subsidiary CKW handled installation and grid connection in cooperation with energieUri.
The projects were announced in September 2025, with construction commencing shortly afterward. Commissioning was completed in the first half of 2026 as originally planned.
The Gurtnellen project represents a significant scale-up from Axpo’s first Swiss BESS, a 2MW/2.17MWh system deployed in 2019. The company has stated plans to reach several hundred megawatts of installed storage capacity over the next three years across multiple European markets.
Axpo has already deployed a 20MW system in Sweden in February 2024 and acquired a 25MW project there in 2023. The firm also secured a contract in Poland’s 2024 capacity market auction for a BESS to be delivered in 2029.
Switzerland has historically focused on large-scale pumped hydro storage, including a 20GWh facility that came online in 2022. The country has also seen development of alternative technologies, including a proposed 1.6GWh flow battery project.
In May of this year, Invinity Energy Systems was selected to design and deliver the world’s largest flow battery for a data centre in Switzerland under construction by Flexbase.
Axpo has also been active in the US. In April, the company executed an energy storage revenue swap agreement for the 220MW/440MWh Hidden Lakes Reliability Project in Galveston County, Texas with Gridstor, a US-based developer and operator of grid-scale BESS.
