The overhaul of turbines at the Melo hydropower plant in Nokia, Finland, has been completed, returning the facility to full operation and extending the lifespan of its equipment.
The project concluded with the first of the plant’s two Kaplan turbines re-entering service following refurbishment in the second phase of works. The 69.7MW capacity plant is located on the Nokianvirta, part of the Kokemäenjoki water system.
“After the refurbishment, the power plant’s technology is now in at least as good condition as that of a brand-new installation. At Melo, the turbines were last comprehensively refurbished nearly 30 years ago. With daily maintenance and monitoring, we can ensure that the work we have now completed will serve us well for decades to come,” said Juha Kähkölä, Project and Investment Manager at PVO-Vesivoima.
The investment decision was made in spring 2024, with refurbishment carried out in two phases. The second turbine was completed first and returned to operation in June 2025. Work on the first turbine began in August 2025, including dismantling, workshop refurbishment of components, and reinstallation in early 2026, followed by test runs in March.
The project was delivered in partnership with Andritz Hydro Oy, while Caverion Suomi handled generator dismantling and installation.
“In the two-phase project, we learned from our earlier experiences and further developed our working methods for the second stage. For example, we fine-tuned certain technical solutions, and during the installation phase we were better able to anticipate upcoming situations, which helped accelerate the work. We operated as the same team for nearly one and a half years, building a strong sense of team spirit and shared purpose. It was also great that the work was carried out by local experts from our partners and their subcontractors,” Kähkölä said.
The phased approach allowed the plant to remain largely operational throughout the upgrade. However, a minor oil leak in the second turbine led to a temporary suspension of its electricity production in late February 2026.
“The minor leak was detected in the 2. turbine — refurbished the previous year — before the 1. turbine had been returned to operation. Importantly, we were able to contain the leak effectively and trace its source to the turbine’s runner. Now that the refurbishment is complete and the 1. turbine is back in production, we are working with the equipment supplier to investigate the cause of the leak in the 2. turbine in more detail and to carry out the necessary repairs,” Kähkölä said.
The turbine overhaul forms part of PVO-Vesivoima’s long-term refurbishment programme. Previous upgrades include reinforcement of the Melo embankment dam in 2022 using a bored-pile wall, and modernisation of electrical automation systems in 2014–2015. The plant now meets current hydropower standards.
PVO‑Vesivoima Oy is part of the Pohjolan Voima Group.
