Kemijoki Oy continues preliminary planning of a pumped storage hydropower plant at Ailangantunturi in Kemijärvi

Kemijoki Oy is accelerating Finland’s safe energy transition and will continue preliminary planning of a pumped storage hydropower plant located at Ailangantunturi in the City of Kemijärvi. At the same time, the company will continue exploring the possibility of constructing additional pumped storage hydropower plants in Northern Finland.

The fall height of the pumped storage hydropower plant at Ailangantunturi would be approximately 200 metres, enabling the construction of a large-scale 550-megawatt pumped storage hydropower plant and providing a significant improvement to the security of supply of Finland’s electricity system. Pumped storage enables storing electricity at exceptionally high efficiency rates.

The importance of dispatchable hydropower to energy self-sufficiency and security of supply will increase as Finland shifts from fossil fuels to renewable energy. The rapid growth of wind power in particular creates more demand for balancing in the energy system in the form of energy storage and demand response, among others.

As part of the planning phase, Kemijoki Oy will carefully model and assess impacts from the construction and operation of the pumped storage plant at Ailangantunturi. The company has already begun discussions with the City of Kemijärvi as well as local landowners and will initiate the environmental impact assessment of the project in 2023.

“It is great to see that Lapland is attracting green transition investments. Looking ahead, it is important to determine not just the environmental impact of pumped storage but also the effect of potential new investments to Lapland’s regional economy and development,” says Mika Riipi, County Governor of the Regional Council of Lapland.

Apart from Ailangantunturi and as announced this spring, Kemijoki Oy is exploring the possibility of building several pumped storage hydropower plants of similar scale in the Kemijoki water area. The scale of the potential investments could total approximately 3 billion euros, of which the Ailangantunturi plant accounts for 600–800 million euros.

“As a large-scale energy storage technology, pumped storage has been tried and tested elsewhere in the world, but it is new in Finland. Over 70 years of operation, we have gained a vast amount of hydropower expertise, which we are now applying as we map the potential of and make plans for pumped storage hydropower plants. The aim of our operations is to ensure that Finnish electricity consumers – households, companies, and industry – have enough low-emission electricity in all situations,” says Tuomas Timonen, CEO of Kemijoki Oy.

According to Kemijoki Oy’s assessment, pumped storage hydropower plants will decrease the price of wholesale electricity while stabilising the fluctuations in and improving the predictability of electricity prices. Pumped storage hydropower enables the expansion of wind and solar power generation by increasing dispatchable electricity production that can quickly balance shifts between production and consumption.

Info box: The pumped storage hydropower plant in Ailangantunturi

  • Pumped storage hydropower acts as a hydroelectric battery and helps balance Finland’s electricity system. Distributed electricity production improves national security of supply.
  • The pumped storage hydropower plant will produce power when demand for electricity is high or when there is a disruption in the electricity system. When it is windy or sunny and there is an oversupply of electricity, the plant will pump water back up into the upper storage lake.
  • Water will be run through turbines down from the upper storage lake of the Ailangantunturi plant and into Lake Kemijärvi. Pumping water from the lake into the upper storage lake takes as long as it takes to empty the upper lake, i.e., 7–9 hours.
  • The size of the upper storage lake is approximately one square kilometre, equal to the land area required by 1–2 wind turbines. The pumped storage plant’s structures will be mainly located underground.
  • The Ailangantunturi plant can be connected in part to an already existing electricity transmission network.
 Image of the pumped storage hydropower plant

Additional information

Tuomas Timonen
Kemijoki Oy
Phone +358 20 703 4410

Kemijoki Oy

Kemijoki Oy is a pioneer of sustainable and flexible hydroelectricity. The company owns 20 hydropower plants, 16 of which are in the Kemijoki water area, two in the Lieksanjoki river, and two in the Kymijoki river. Additionally, the company regulates the Lokka and Porttipahta reservoirs as well as Lake Kemijärvi and Lake Olkkajärvi. In 2022, Kemijoki Oy’s hydropower plants produced 4,750 GWh of renewable hydroelectricity that is used to mitigate climate change and support Finland’s security of supply. More information is available on Kemijoki Oy’s website at

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