Commercial electricity production at the Pyhäsalmi mine solar park started

Electricity production at the Callio solar park started on 4 June 2025. The investment decision for the project was made in the summer of 2023 and construction began in December 2023. The start of electricity production has required seamless cooperation between many different operators, so the first day of production was an important achievement.

"The Callio solar park will be completed at the sunniest time of the year. The last challenges of the construction phase have now been overcome and the commissioning has gone smoothly. In terms of production, we can get straight to maximum power. We thank Solarigo Systems for bringing the power plant into production readiness," says Niko-Lassi Kurtti, Chief Development Officer, Skarta Energy.

The size of the solar park, which has a panel capacity of 13 MWp, is considerable. A total of
22,800 solar panels have been installed in the park. The annual production of the solar power plant is about 10 GWh, which corresponds to the annual consumption of almost 1300 Finnish households. The electricity produced by the park will mainly be utilised on site. When the underground operations of the Pyhäsalmi mine end, the Callio business area will be developed in the vicinity of the mine, the operators of which will make use of the mine's existing infrastructure and solar park.

"The development and construction of Callio has gone smoothly in cooperation with the mining company, the municipality and several other operators. Although the park itself is now complete, the project will continue with the design of the battery solution. We are planning a 4 MW (8 MWh) battery solution for Callio," says Project Manager Simo Rintakari, who was responsible for the Callio project.

One of the goals of Callio's project was to create the conditions for harnessing the decommissioned mining areas for solar power production. In December 2022, the Ministry of Economic Affairs and Employment granted a total of EUR 12.1 million in Next Generation EU grants to the Callio and Hitura solar power projects. However, the Hitura project is still waiting for the closure of the mining concession before legally valid permits for construction can be granted.

"The project is a great demonstration of how unused areas that have been modified by humans and have very low natural values can be harnessed for the production of renewable energy. Now, the decommissioned tailings pond of the Pyhäsalmi mine has in a way got a new start and will serve as an energy production plant for at least the next 40 years. The EU grant received was therefore a significant accelerator when considering the investment decision," says Santeri Ahokas, Senior Vice President, Project Business, Skarta Energy.

"The project was implemented in accordance with the restrictions set by the area's environmental permit as a completely floating solution, which required special care from the perspective of the project's design and construction. Investing in pre-engineering made the construction phase much easier, allowing the installation of the power plant to be carried out on schedule and without major challenges," says Juho Lasonen, Senior Project Manager, Solarigo Systems Oy.

It was important for the mine that the area could be used for other purposes when mining operations ended.

"The project has been well executed and the cooperation with Skarta Energy and Solarigo's project organizations has gone very well, even though the construction site is exceptional," says Aki Tuikka, General Manager, Pyhäsalmi Mine.