Fimpec in charge of project manage­ment at the Kuhan­koski hydro power plant project

Photos: Tomi Immonen

The Kuhankoski hydro power plant is Koskienergia Oy’s largest investment to date, with a budget of more than EUR 20 million. The project involved the construction at Kuhankoski of a modern hydro power plant and an entirely new channel, partly flowing through a tunnel in the rock. Furthermore, a new natural fish pass was built for migratory fish alongside the old technical fish pass. Kuhankoski’s old power plant, built between 1919 and 1925, will remain operational alongside the new hydro power plant as a backup facility.

The new power plant will generate around 40 per cent more electricity than the old plant and increase annual production from under 25 GWh to 35 GWh.

The project was completed on schedule

Fimpec’s Tomi Rissanen, the project’s project manager, safety coordinator and construction supervisor, describes the project as unique. New hydro power plants like the one at Kuhankoski have not been built in Finland for decades. The project was challenging and long. Building worksite infrastructure, rock engineering (including excavation), the extremely demanding casting in-situ of the power plant and the coordination of the work between different parties demanded a lot from everyone involved.

“For example, approximately 130 in-situ castings were carried out over eighteen months on a hundred separate days, with the size of the cast parts ranging from a few cubic metres to several hundred cubic metres. They also included the attaching of huge turbine parts. As the turbine parts were cast in-situ in the concrete structure in three phases as the work progressed, the schedules of the main contractor SRV Infra and the plant’s turbine supplier Andritz had to be synchronised carefully,” he says.

Despite the challenges, the project achieved completion on schedule. Rock engineering and opencast mining began in November 2020, tunnel excavation in the beginning of 2021 and the casting in-situ of the power plant began in June 2021. The power plant building was erected using precast concrete elements in around a month in summer 2022, after which the in-situ casting continued until November.

The construction project was finished in January 2023, followed by the installation of equipment and automation-related work and finishing work on the construction project. The power plant’s test production began in March 2023, and regular production started in April. Since then, finishing work has been carried out at the power plant. The plant’s official inauguration was held on 2 June 2023.

“We got the project across the finish line on schedule through excellent co-operation between the various parties. The importance of staying on schedule was highlighted when we were able to benefit from the spring floods, and both power plants were running at full capacity for a few weeks before the river began to subside,” Rissanen sums up.

Budget and quality went hand in hand

They were able to stay within the project’s budget of just over EUR 20 million. Rissanen estimates that this was the result of, above all, Koskienergia’s quick and clear decision-making, flexible collaboration with the equipment supplier, predicting challenges, precise project management and supervision of the work. He points out that quality is extremely important in projects of this kind because the structures are difficult to fix after the fact.

According to Rissanen, one major success related to occupational safety: despite the extremely difficult circumstances, only two lost-time incidents occurred at the worksite, each leading to only a few days of sick leave.

A green transition project in safe hands

Over the years, Fimpec has participated as an engineering and project management partner in several key green transition projects, such as wind, solar and hydrogen plants.

“Hydro power is a key resource in Finland and at Kuhankoski, Koskienergia Oy has taken a modern approach to the challenges resulting from self-sufficient energy production in a changing world. In this project, together with Koskienergia, AFRY, SRV, Insta and Andritz, we have been able to carry out thorough work in engineering, technical solutions and project implementation,” stated Fimpec’s Business Unit Director Jorma Paananen at the power plant’s inauguration.

New Kuhankoski power plant

• Maximum power 5.4 MW.
•  Annual production approx. 35 GWh, and almost 40 GWh together with the old power plant.
• Two turbines and generators.
• Water is steered into the new power house along a new 100-metre tunnel.
• The drop height is approx. 3.5 metres (based on the height of the lakes Saraavesi and Lappvesi).
• A maximum of 160 m3 per second of water flows through the two new turbines.
• A natural, winding fish pass was built between the new and old power houses.
• The project included the building of a heat recovery system, which recovers the heat generated by the transformers and new power house and uses it to heat the old power plant.
• The budget was just over EUR 20 million.
• Construction took place from 2020 to 2023.

For more information, please contact:

Jorma Paananen, Business Unit Director, Fimpec PMO
tel. 040 347 373, jorma.paananen(at)fimpec.com

Tommi Rissanen, Project Manager, Fimpec PMO
tel. 040 556 7828, tommi.rissanen(at)fimpec.com

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