Neoen Breaks Ground on Finland’s First 4-Hour Battery in Rauma

Neoen has provided notice to proceed to battery storage expert Nidec, signalling the start of construction of Akkula Big Battery located next to Hevossuo waste management site in Rauma, Finland. Nidec will act as the main contractor for the project, overseeing construction and providing the battery containers, battery cells, and inverters. The Akkula Big Battery will comprise 30 battery containers and, with a capacity of 62.5 MW / 231 MWh over four hours, will be the first large-scale long-duration battery in the Nordic region. The facility will be connected to Fingrid’s nearby 110 kV overhead transmission line, and Neoen will retain full ownership of Akkula as well as responsibility for its long-term operation.

The battery will participate in both Fingrid’s reserve markets and the wholesale electricity market, delivering rapid-response ancillary services that support the balance between electricity generation and demand. By enhancing frequency control and overall system security, the project will help strengthen the power system and enable greater integration of renewable energy. The battery also features grid-forming technology and can provide inertia to the network. In addition, Business Finland has awarded the Akkula Big Battery a tax credit under its scheme for large clean-transition investments, and the project represents Neoen’s fifth battery installation in the Nordic region.