Developer Ilmatar and investor Nuveen Infrastructure have put a 30MW/41MWh BESS in northern Finland into commercial operation.
The companies have commissioned the 1.36-hour Ainola battery energy storage system (BESS) project at the Piiparinmäki wind farm in the North Ostrobothnia region.
Ilmatar said it is one of the largest BESS in Finland that is directly connected to renewable energy production, indicating it at least shares some grid infrastructure with the wind farm, most likely an interconnection point. Energy-Storage.news has reached out to Illmatar for clarification on this aspect.
The BESS will participate in the wholesale electricity market via the day-ahead and intraday markets and is in the process of being approved for the reserve markets.
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“We are very pleased and proud that the Ainola BESS – whose development and deployment required pioneering solutions and a forward-looking approach – has now reached commercial operation and full market capability,” said Mika Jantunen, head of technology at Ilmatar.
Ilmatar developed and built the project and retains a 10% stake in its equity, while investment firm Nuveen Infrastructure owns the other 90%, having acquired the wind farm from Ilmatar in 2019. Or rather, Glennmont Partners acquired the project and then was acquired by Nuveen in 2021.
The project was co-developed by Glennmont Partners and, according to the information provided when construction was launched in 2023, the BESS was provided by Netherlands-based system integrator Alfen. Nuveen has since re-branded Glennmont to Nuveen Infrastructure.
The project was initially scheduled to come online in Q2 2024.
In late 2023, Ilmatar scored planning consent for 50MW PV, 20MW BESS in Finland, and the company is also working with ‘Sand Battery’ technology company Polar Night Energy to developer power-to-heat-to-power applications for its thermal energy storage tech. Polar Night Energy just commissioned its largest project yet, a 1MW/100MWh system for district heating.
Opportunities in Finland’s energy trading and ancillary service market are growing as its renewable energy generation does, driving the large-scale BESS market. In 2025 alone, large-scale projects (30MW-70MW) have been launched by Eco Stor AS, Ingrid Capacity and SEB Nordic Energy, NTR, Renewable Power Capital (RPC) and Ardian.
