Callio is a multidisciplinary underground operating environment in the Pyhäsalmi Mine, Finland, offering facilities for energy storage, R&D, testing, and business development at 1,445 metres depth.

Where is Callio located?

Callio is headquartered in Pyhäsalmi, Finland.

What energy sectors does Callio operate in?

Callio operates in Energy Storage, Hydro, Solar.

Back to directory

Callio

Pyhäsalmi, Finland

Energy StorageHydroSolarPrivate

Visit website

About

Callio is a private headquartered in Pyhäsalmi, Finland specializing in Energy Storage, Hydro, Solar.

Callio is located in the Pyhäsalmi Mine, one of Europe's deepest mines at 1,445 metres underground. The facility provides a unique, stable environment for innovative projects and established operators. It hosts underground pumped hydro energy storage (UPHS) projects, battery energy storage systems (BESS), solar parks, R&D laboratories, testing facilities for mining and industrial technologies, and data center development. Key projects include a 170 MWh battery storage facility and Finland's first solar park built in a mining area (commissioned June 2025). The facility also serves as a testing ground for advanced technologies including autonomous vehicles, 5G communications, and navigation systems.

underground facilityenergy storageR&Dtesting environmentmining repurposingindustrial innovation

Headquarters

Pyhäsalmi, Finland

Company Type

Private