Insta delivered the modernization of the automation and electrical systems for the Jumisko hydropower plant and the Isojärvi pumping station for PVO-Vesivoima, part of the Pohjolan Voima Group, as part of a major refurbishment project. As a result of the refurbishment, the plant’s efficiency improved by approximately six percent and its output increased by two megawatts. Control capabilities and energy efficiency were enhanced, and the plant is now able to provide balancing power that is essential for maintaining grid stability with greater flexibility.
Hydropower accounts for nearly one fifth of Finland’s domestic electricity production. Its role in balancing the electricity grid is becoming increasingly important as weather-dependent renewable energy sources such as wind and solar power continue to grow.
In addition to increasing the plant’s output, the modernization reduced the risk of production interruptions associated with systems that had reached the end of their lifecycle. The refurbishment supports security of supply, improves production responsiveness, and extends the plant’s operational lifetime by decades.
Located in Kemijärvi, the Jumisko hydropower plant was commissioned in 1954. In the early 1950s, Finland’s forest industry was making significant investments, and concerns were growing about future energy shortages. To secure power availability, Pohjolan Voima began planning a hydropower plant in the Jumiskojoki watershed in 1951.
The plant, built inside bedrock, featured a hydraulic head of 96 meters, higher than that of any other hydropower plant in Finland at the time. More than seven kilometers of tunnels were excavated, and twelve kilometers of open canals were constructed between regulation reservoirs. Because the facility was built in remote wilderness in the challenging conditions of post-war Finland, and because both drilling expertise and much of the equipment had to be sourced from abroad, the project was exceptionally demanding.
The previous major refurbishment of the Jumisko plant had taken place in the 1980s. By the time the 2021 modernization project began, the turbine that had first started operating at the turn of the year 1954 had reached the end of its service life. The plant’s systems also required renewal.
“During the refurbishment, the original turbine from the 1950s was replaced with a new one. Automation and electrical systems that had reached the end of their lifecycle were replaced with modern solutions. In addition, the plant’s generator was serviced,” says Juha Kähkölä, Development Manager at PVO-Vesivoima.
Modern Automation and Electrical Systems Increase Power and Reliability
Modern automation and electrical systems play a significant role in improving both efficiency and operational reliability. They enhance the plant’s control capabilities and enable unmanned remote operation.
Modern remote and local control systems allow the plant to be operated more precisely, making operation easier. The new system also provides more extensive information about the plant’s condition and offers improved diagnostics. The data generated by the system enables better predictability than before.
“The new equipment increases both output and reliability. Production can be controlled more accurately according to changing electricity demand while also taking environmental and recreational requirements into account. Remote monitoring and maintenance planning have become more efficient as well,” says Kähkölä.
A Unique Location and Operating Concept Made the Project Especially Interesting
The renewal of the Jumisko automation and electrical systems included plant, machinery and turbine automation systems, generator excitation and protection systems, medium- and low-voltage systems, DC systems, power system studies, compliance with the VJV2018 requirements of Finland’s transmission system operator, and the design and verification of reserve market operating and disturbance reserves.
Insta, which supplied the automation and electrical systems for both the hydropower plant and pumping station, partnered with PVO-Vesivoima for the first time in the Jumisko modernization project. The new turbine was delivered by Czech manufacturer ČKD Blansko Holding a.s. The project involved numerous designers, installation specialists and commissioning engineers.
“This was an important and exciting opportunity for us to carry out a major project for PVO-Vesivoima. The refurbishment was particularly interesting because of the plant’s unique location and operating principle. Water is conveyed to the Jumisko plant through lakes, canals and a 7.5-kilometre tunnel. The machinery itself is also exceptional, as it is located more than one hundred meters underground in a cavern excavated inside bedrock,” says Aki Mahlanen, Vice President of Energy Business at Insta.
The Jumisko power plant has been excavated into the rock.
“The automation and electrical delivery for the hydropower plant and pumping station was implemented as a complete turnkey project, from engineering to commissioning and training. Engineering work began in 2019. Installation and commissioning activities started in early 2021 and continued through the summer,” Mahlanen continues.
At the same time as the plant received a new turbine as well as new automation and electrical systems, the tunnel entrances were repaired and cleaned, and the concrete structures of the regulation dams were refurbished.
After a twelve-week shutdown, the plant was recommissioned and first operated in test mode before returning to electricity production in July 2021.
Broad Automation Expertise Created Added Value
As a result of the refurbishment, the efficiency of the Jumisko plant improved by approximately six percent and its output increased by two megawatts.
According to Juha Kähkölä, renovating an existing facility presents challenges different from those of building a new one, and the exceptional circumstances of the COVID-19 pandemic added further complexity.
“Planning and carrying out the work during the pandemic was challenging and required more preparation and contingency planning than usual. We paid particular attention to health and safety on site and followed very strict safety procedures,” says Kähkölä.
Kähkölä praises Insta for its agility and flexibility. According to him, the broad automation and electrical expertise that Insta has developed across multiple industries brought additional value to the project.
“To us, Insta is a company that listens to the customer and operates with flexibility. It is extremely important that a supplier has the expertise and willingness to challenge ideas when necessary. It was a positive surprise that Insta already had excellent proposals and valuable insights during the sales and tendering phase,” says Kähkölä.
“Cooperation was smooth from the beginning. The project clearly demonstrated PVO-Vesivoima’s comprehensive expertise, extensive experience in hydropower modernization projects, and deep understanding of electricity generation,” says Mahlanen.
“During the project, challenges emerged that are typical of modernizing an old hydropower plant. Nevertheless, everything was completed on schedule, and the project as a whole was successfully delivered.”
“The Jumisko hydropower plant is truly unique in Finland. It was a privilege to be involved in the modernization of such an exceptional facility.”
Photos: Juha Kerkelä, Pohjolan Voima