EXECUTIVE SUMMARY
France-based renewable energy developer Neoen has begun construction of the 62.5 MW / 231 MWh Akkula Big Battery in Rauma, Southwest Finland. Finland’s first large-scale 4-hour BESS, Akkula will provide fast-response ancillary services, support frequency control, and enable higher renewable penetration. Fully owned and operated by Neoen, the project leverages existing grid infrastructure and is expected to enter commercial operation in 2027. Construction will create ~40 jobs, with long-term community benefits over a 25-year operational period.
Company: Neoen
Location: Rauma, Finland
Project: Rauma BESS
Capacity: 62.5 MW / 231 MWh
Technology: Lithium-Ion Grid-Forming BESS
Construction Partner: Nidec
PROJECT SNAPSHOT
France-based renewable energy developer, Neoen has announced the start of construction of 62.5 MW / 231 MWh Akkula Big Battery in Rauma, Southwest Finland. The project represents Finland’s first large-scale 4-hour battery energy storage system and one of the largest battery installations in the Nordic region.
Akkula Big Battery represents the Neoen’s third battery project in Finland, bringing the company’s total storage capacity in the country to 149 MW / 374 MWh. The project is fully owned by Neoen, which will be responsible for the long-term operations. Akkula is scheduled to reach full commercial operation in 2027 and has been developed next to the Hevossuo waste management site, using existing grid infrastructure and compatible land use.
Neoen has provided a notice to proceed to Nidec, which have the overall responsibility of construction of the project. Nidec will supply the battery containers, battery cells, and inverters. The facility will consist of 30 battery containers and will be located adjacent to the Hevossuo waste management site in Rauma, Finland. The project will be connected to Fingrid’s 110 kV overhead transmission line located next to the site, enabling integration with Finland’s transmission network.
Once operational, Akkula will operate in Fingrid’s reserve markets and the electricity wholesale market. The battery will provide fast-response ancillary services to support the balance between electricity supply and demand. These services will support frequency control and power system security while enabling higher penetration of renewable generation in Finland. The Akkula BESS includes grid-forming functionality and the capability to provide inertia to the transmission system.
The project has received financial support in the form of a tax credit for large clean transition investments granted by Business Finland. During the construction phase, Akkula is expected to create approximately 40 jobs, along with additional work opportunities for local contractors and suppliers. Over its planned 25-year operational period, the project will implement a benefit-sharing program for local communities in the Rauma area.
The project follows earlier developments such as Yllikkälä Power Reserve and Yllikkälä Power Reserve Two. In addition to its battery assets, Neoen operates and is constructing multiple wind power projects in Finland, including Mutkalampi, Hedet, Björkliden, Lumivaara, and Storbötet. Across all technologies, Neoen has more than 830 MW of capacity either in operation or under construction in the country, supported by several corporate power purchase agreements.
At the Nordic level, Akkula represents Neoen’s fifth battery project in the region. Globally, the company holds a battery storage portfolio totaling 2.5 GW / 7.0 GWh in operation or under construction, reflecting its continued expansion in large-scale energy storage markets.