Statkraft begins 54 GWh expansion for Norway’s largest hydropower reservoir

Norway’s Ulla-Førre power plants will see annual production increase by 54 GWh due to a planned increase in the country’s largest reservoir, according to Statkraft.

The Norwegian energy company has it will build the proposed Blåfjell Pump, which will channel more water directly into the Blåsjø reservoir –described by Statkraft as Norway’s “largest hydropower battery”.

Statkraft has awarded four contracts totaling NOK 250 million ($26 million) for construction of the new water pump, with work on Blåfjell Pump set to begin immediately.

A Statkraft spokesperson confirmed to ESS News that the increased capacity will come as the result of pumping more water into the reservoir, giving the power plant below more opportunities to deploy throughout the year.

Blåsjø reservoir stretches across Ryfylke and Setesdal and is Norway’s largest reservoir in terms of stored energy. The reservoir is capable of storing water for several years to balance out weather related variations between dry and wet years.

The new pump is being built to increase production at the Ulla-Førre power plants which are served by Blåsjø. Under current arrangements, there are three smaller lakes west of Blåsjø which currently flow down to Stølsdal power plant, at a lower level in Ulla-Førre system. Statkraft explained that due to flood losses and constraints in the water course, the water can be used much more efficiently by instead being lifted 60 meters up into the Blåsjø river.

Works on the project will include creating a transfer tunnel and a pumping station inside a mountain, as well as several smaller transfer structures. Statkraft is aiming to commission the pump by December 2027.

Statkraft also plans to carry out improvements required in Norway’s water resources and energy directorate on four dams at the western end of Blåsjø. These works will be undertaken at the same time as pump construction, according to Statkraft, with the goal of completing all work during 2028.

“Finally, after many years of planning and adjustments, we have found a profitable way to carry out the project,” explained Pål Otto Eide, executive vice president for development at Statkraft.

“Getting more water into Blåsjø is perhaps one of the most valuable things we can do for society because the reservoir can store the water for several years and we increase generation in existing hydropower plants.

“In this way, significantly more energy can be generated from an already developed system, with limited additional impact on nature.”

The Blåfjell Pump investment is part of a long-term hydropower strategy from Statkraft. The company plans to invest NOK 70 billion in Norwegian hydropower over the next ten years.

“The Blåfjell Pump is one of many projects Statkraft is carrying out to help build and strengthen Norway. In total, our investments in the coming years represent one of the largest industrial boosts in the country,” Eide added.