The overhaul of the turbines at the Melo hydropower plant, located on the Nokianvirta, part of the Kokemäenjoki water system in Nokia, has been completed. The project concluded when the 1. turbine of the plant’s two turbines — refurbished in the second phase — was handed back into operation. The refurbishment extends the lifespan of the plant’s machinery and ensures stable electricity production.
“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,” says Juha Kähkölä, Project and Investment Manager at PVO‑Vesivoima.
The investment decision for the refurbishment project was made in spring 2024, and the work was carried out in two phases. The 2. turbine, refurbished first, returned to operation in June 2025. In the second phase, refurbishment work on the 1. turbine began in August 2025 with dismantling of the machinery. The turbine components were refurbished in a workshop, and installation work began in early 2026, followed by test runs in early March. The refurbishment was carried out in partnership with Andritz Hydro Oy, while Caverion Suomi was responsible for dismantling and installation of the generator.
“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 says.
Because the work was phased, the power plant remained in normal operation for almost the entire refurbishment period. The only exception was a minor oil leak, which led to the suspension of electricity production from the second turbine at the end of 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 says.
The overhaul of the Melo hydropower plant’s turbines is part of PVO‑Vesivoima’s long‑term investment and refurbishment programme. In 2022, the Melo embankment dam was repaired and strengthened with a bored‑pile wall — a Finnish innovation. The plant’s electrical automation was modernised in 2014–2015. Following the turbine refurbishment, the Melo hydropower plant now fully meets modern hydropower requirements.
Further information:
Juha Kähkölä, Project and Investment Manager, PVO‑Vesivoima Oy
juha.kahkola@pvo.fi, tel. +358 50 303 8622
Melo hydropower plant
- Located on the Nokianvirta, part of the Kokemäenjoki water system, in Nokia
- Commissioned in 1971
- Turbines previously refurbished in 1998–1999; generators in 2014–2015
- Plant capacity: 67.9 megawatts
- Two Kaplan turbines
PVO‑Vesivoima Oy produces electricity at hydropower plants on the Iijoki, Kemijoki and Kokemäenjoki rivers. Its electricity production averages 1.8 terawatt‑hours per year. The company is part of the Pohjolan Voima Group. www.pohjolanvoima.fi.