Romanian Developer Monsson Brings Battery Facility Online in Eskilstuna, Sweden

Monsson has launched Eskilstuna Power Reserve, the Romanian renewable energy company's first battery energy storage project in Sweden.

First Swedish storage investment reaches commercial operation

The facility pairs a 30 MW power rating with 60 MWh of storage capacity, configured for a two-hour discharge duration. Commissioning began in September 2026 and, according to the company, has now been completed, with commercial operation scheduled for November 2026.

The launch was marked by an event held on 22 October in Eskilstuna under the theme "Storing Energy, Powering Generations", attended by representatives of Sweden's energy industry, grid operators, authorities and the business community. The programme included presentations on the project's technology and business model, discussions with the Monsson team and guided tours of the facility ahead of commercial operation.

Fast-response flexibility for the SE3 zone

The system is built to deliver flexibility in power system operation and support grid stability within Sweden's SE3 bidding zone. It can switch between charging and discharging in under three seconds, allowing a rapid response to fluctuations in electricity generation and consumption. The project relies on Monsson's proprietary technology and the company's track record in developing, engineering and deploying utility-scale storage facilities. According to Sebastian Enache, Head of Strategy & M&A at Monsson, Eskilstuna Power Reserve represents an important step in the company's expansion into the Nordic market.

He said the 30 MW / 60 MWh project brings Monsson's energy storage technology and expertise to Sweden with the aim of contributing to grid flexibility and stability, and that the team in Sweden, together with colleagues in Romania, is ready to provide these flexibility services both locally and across Europe.

Joanna Lillequist, CEO of Monsson Energy AB, said the project expands the company's portfolio of storage solutions intended to support European energy systems with a growing share of renewable generation. In her view, it provides a foundation for continued development in the Nordic region, where flexibility and efficient energy management are important components of energy infrastructure.

European supply chain highlighted at launch

Daniel Ioniță, Ambassador of Romania to Sweden, described the facility as Romanian expertise at work in Sweden, designed, built and operated by Romanian professionals with technology developed at home and applied abroad.

He noted that more than 95% of the facility's components are manufactured in EU member states, calling it an example of how European strategic autonomy is built in practice. According to the ambassador, the facility strengthens Sweden's energy transition and the security of the regional power system, and demonstrates that Romania is competitive on the European energy market.

Municipality sees foundation for long-term partnership

Daniel Lindekrans Henriksson, Energy Strategist at Eskilstuna Municipality, said Eskilstuna has long pursued an ambitious energy agenda, with goals of becoming truly fossil-free and climate positive by 2045.

He said the investment provides a new capability for Eskilstuna and Strängnäs and that batteries can deliver multiple benefits for both the national and local grid. He described the project as the start of a long-term partnership, noting that ESEM, the municipality, is eager to innovate together to realise the potential, for example through its new local flexibility market.

Two decades in renewables behind Nordic push

Monsson has operated in Romania's renewable energy sector for more than 20 years and has become a significant supplier of electricity generated from renewable sources, with a portfolio exceeding 5 GW across wind and solar projects.

The company offers turnkey services spanning the design, development, construction and operation of renewable power plants, along with the construction and operation of battery energy storage solutions. The Eskilstuna project marks the extension of these activities into the Nordic market and the growth of the company's energy storage business. Media contact for the project is Sebastian Enache, Head of Strategy & M&A at Monsson.