Solarigo develops the Callio solar park: one of Finland’s first utility-scale solar + BESS hybrid systems
Solarigo is adding a battery energy storage system (BESS) to the Callio solar park in Pyhäjärvi, marking another step towards smarter and more optimised energy solutions. The project represents one of the first hybrid systems in Finland to combine solar power with battery energy storage.
The project integrates a 13 MWp solar park with a 4 MW / 8 MWh battery energy storage system into a single, optimised entity. The objective is to maximise the system’s ability to participate in electricity markets while supporting the overall energy system.
The battery energy storage system for Callio is supplied by WEG.
The Callio solar park is a joint project by Solarigo Systems, Skarta Energy, the City of Pyhäjärvi and the Pyhäsalmi mine. The project was built on a decommissioned and backfilled tailings area of the Pyhäsalmi mine. Commercial electricity production at the Callio solar park began in June 2025. The Callio solar park and battery energy storage project have received funding from the Finnish Ministry of Economic Affairs and Employment through the Next Generation EU recovery programme.
Hybrid solution improves market optimisation
Combining solar power with battery storage enables generation and storage to be managed as a single system in response to market conditions. The battery adds flexibility to the solar park and improves overall controllability, allowing for more active participation in electricity markets, including reserve markets.
In a hybrid system, the focus is not on individual assets, but on optimising the performance of the entire system. The aim is to utilise generation, storage and market opportunities in the most efficient and economically sound way.
“We have experience in asset optimisation and operating in electricity markets, and we see hybrid systems as a natural next step. Battery storage strengthens the market value of solar power and enables more active participation in, for example, reserve markets.
Eero Yliselä, Asset Management Director, Solarigo.
First hybrid project supports Solarigo’s strategic direction
The Callio battery energy storage project is Solarigo’s first to combine solar power and battery storage. The battery is built alongside the solar park and forms an important part of Solarigo’s strategic development.
Solarigo is advancing towards a multi-asset approach, where multiple energy storage, generation and consumption systems are managed as one integrated whole. Hybrid models create synergies through shared infrastructure and improved operational optimisation, enhancing overall project profitability.
“Looking ahead, Solarigo will focus increasingly on developing and operating integrated systems that combine multiple energy units, allowing us to capture market opportunities efficiently and over the long term. We will be delivering several battery storage and hybrid projects during 2026, and will share more details in the near future,” says Eero Yliselä, Asset Management Director at Solarigo.
Construction and project management as part of comprehensive expertise
Solarigo delivers both standalone battery energy storage systems and solutions integrated into hybrid parks. The development, construction and project management of battery energy storage systems are a core part of Solarigo’s expertise and a growing area of its business.
The Callio project brings together development work, technical execution and a market-driven approach. The battery energy storage system is not a separate add-on, but an integral part of the overall solution, enabling increased value creation through market-based optimisation.
