The overhaul of PVO-Vesivoima’s Jumisko hydropower plant in Kemijärvi has begun. The overhaul will improve the power plant’s capacity to produce regulating energy that will provide an important balance to the national power supply and improve energy efficiency.

The power plant’s turbine, which dates back to the 1950s, will be completely replaced by a new turbine, and the electricity and automation systems that have reached the end of their service life will be replaced by modern systems during the overhaul of the Jumisko hydropower plant. Furthermore, the generator will be serviced. The overhaul is part of Pohjolan Voima’s systematic power plant overhaul programme.

Better regulating capability and energy-efficiency

The Jumisko power plant is one of the hydropower plants producing regulating power, which is necessary for the balance of the electricity system. Balancing electricity production through renewable hydropower is necessary to support the growing volume of wind and solar power. The overhaul increases the regulating capability of the Jumisko power plant, as well as its power.

  • “Thanks to modern equipment, the power plant will be more able to produce renewable electricity flexibly and reliably. The new turbine technology is more efficient, and modern electricity and automation systems improve the opportunity to control the power plant, as well as enhance remote operation control. The plant will also become more energy efficient,” says Jukka Kähkölä, Development Manager at PVO-Vesivoima.

The power plant’s capacity will increase by 1.5 MW, and electricity production volume by 6 GWh per year. The supplier of the new turbine is ČKD Blansko Holding, a.s. from the Czech Republic. The new electricity and automation systems will be supplied by Insta Automation Oy.

The power plant will be back in business in June

The work at the power plant started in mid-March as planned. The power plant will restart its operations at the end of June.

  • “The work started with demolition, and the actual installation work will begin in April. The power plant will be reconnected to the grid at the end of June. There are approximately 20 workers in total. At the overhaul site, special attention has been paid to safety due to the Covid-19 pandemic. Strict safety measures and valid guidelines are followed at the site. Everyone coming to the site is tested, and there are special arrangements at the site to prevent Covid-19 spreading,” says Juha Kähkölä.

The repair work in the power plant cannot be seen outside, because the power plant is deep inside the rock, where water is directed via a tunnel. During the overhaul, the mouths of tunnels and structures of regulating dams will also be cleaned and repaired.

Regulation is being carefully planned during the overhaul

Normal permit conditions for regulation are followed during the overhaul. The water level of regulation lakes was lowered under the snow to allow room for spring floods.

  • “Recreational use has been taken into account in the overhaul plans. The objective is that the lakes will have a good water level for recreational use at the beginning of the summer. Water levels and flows are being monitored, and careful plans are being made for regulation in the spring,” says Juha Kähkölä.

For further information
about the overhaul, please contact Juha Kähkölä, Development Manager, PVO-Vesivoima Oy,
tel. 358 50 303 8622,,

about regulation and the environment, please contact Aaro Horsma, Environmental Manager, PVO-Vesivoima Oy,
tel. +358 50 303 8661,

Jumisko hydropower plant

  • Completion year 1954
  • Power plant excavated inside the rock
  • 1 Francis turbine
  • Height of fall 96 m
  • Utilisable flow 36 m3/s, mean flow 14 m3/s
  • Capacity before the overhaul 25.8 MW

PVO-Vesivoima Oy produces electricity with its hydropower plants on the Iijoki, Kemijoki and Kokemäenjoki rivers. The average total annual energy production output of the company is 1.7 TWh. The company is part of the Pohjolan Voima Group. Twitter: @PVOVesivoima.