In Simo, northern Finland, Solarigo Systems Oy has developed one of the country's largest solar power plants. With approximately 120,000 solar panels and a capacity of 70 MWp, the project requires electrical infrastructure capable of reliably carrying the full output of the solar park to the grid. Solarigo selected Alfen Elkamo to supply six SELMA 5.0 MVA transformer substations, manufactured in Pietarsaari, Finland and delivered to the site between April and July 2025.
Supporting Large-Scale Solar Growth
As the scale of solar generation increases, reliable electrical infrastructure becomes increasingly important. At the Simo solar power plant, the transformer substations provide the critical connection through which the renewable electricity generated by the site reaches the grid.
For Solarigo, operational reliability was therefore one of the most important requirements when selecting a substation partner.
Jere Graf of Solarigo Systems Oy explains: "The transformer substation is the bottleneck through which all the energy from the solar park flows. If it goes down, production stops immediately - there's no room for malfunctions."
The Challenge
Developing a solar park of this scale requires more than installing photovoltaic panels. The electrical infrastructure connecting the site to the grid must be able to handle large amounts of renewable generation while delivering the operational reliability needed to keep the plant producing electricity.
Solarigo therefore needed transformer substations that met the project's technical requirements while also providing a strong balance between performance, reliability and cost.
The supplier also needed the experience and delivery capabilities to support a large renewable energy project according to schedule. Solarigo identified Alfen Elkamo's experience with similar projects as an important factor in its decision.
Graf says: "The pricing of the 5 MVA SELMA transformer substation units was competitive and met all our technical requirements. The price-to-performance ratio was spot on, and Alfen Elkamo already had a proven track record of successful similar deliveries."