AFRY participates in a feasibility study on the restoration of Sweden's largest pumped storage power plant


Considering today's increasing electricity needs and more intermittent power availability, it is important to ensure plannable power to make sure that electricity can be produced when the market needs it.

One way to ensure this can be to store energy in so-called water reservoirs, and Vattenfall have started a feasibility study where the possibility of restoring Juktan's pumped storage power plant is being investigated.

As part of the feasibility study, AFRY’s role will be to investigate the technology areas of the existing units, civil work, electricity, and permits. This means that AFRY will help Vattenfall to produce the documentation required for both internal and external decisions to investigate the possibility of restoring Juktan’s pumped storage power plant.

Juktan's power plant is located between the lakes Storjuktan and Storuman in the upper part of the Ume River, 20 kilometers north of Storuman municipality. This power plant was the first large pumped storage plant in Sweden and also the largest pumped storage power plant in operation from 1979 to 1996 with a storage capacity of ~ 30 GWh. An unusual advantage of Juktan's reservoir design is that you can pump water from Storjuktan-to-Blaiksjön with a lower potential and generate with a higher potential from Blaiksjön-to-Storuman.

If Juktan is restored as a pumped-storage power plant, it will be Sweden's largest pumped storage power plant with a storage capacity of approximately 300,000 Tesla batteries. This giant battery can store energy without any major energy losses once the water is pumped to the highest level in the Blaiksjön dam. Furthermore, this type of large-scale energy storage is necessary to stabilise the electricity grid and to help enable the large-scale industrial investments in northern Sweden that are taking place.

The feasibility study is ongoing until mid-2023 and when a decision is made on a return to pump operation, commissioning is expected to be in 2031.