The 86 MW project will result in a significant boost in output from the Hemsil watercourse, with annual production to increase by about 110 GWh, Hafslund Kraft announced recently.
“This project shows how, by thinking innovatively about existing developed watercourses, significant new amounts of power can be obtained by better utilizing water resources. We can get more power from every drop,” said Kristin Lian, the CEO of Hafslund Kraft. “With this investment, we ensure continued power production from the water from Hemsedal to the centre of Gol for the benefit of society for several generations to come,” he added.
Hemsil 3 will draw water from the reservoir impounded by the Eikrebekken dam in Hemsedal, using the same intake point as Hemsil 2. A new tunnel will run parallel to the existing one, and the new powerplant will be built inside the mountain next to Hemsil 2 in Gol, with an outlet placed close to the current discharge into the Hallingdalselva river.
The project includes the construction of a new dam at Eikrebekken, downstream of the existing one, in compliance with the requirements of the dam safety regulations and flood diversion capacity. The new concrete dam will be approximately 12 to 13 m high, with a length of about 505 m, of which 321 m will serve as a permanent spillway.
Construction work, which is being carried out by the main contractor, Leonhard Nilsen and Sønner (LNS), under a contract signed in November 2025, is expected to be completed in mid-2029. Hemsil 3 received its licence from the Ministry of Energy in June 2024. The boards of Hafslund Kraft, Hafslund, and Eidsiva Energi have approved the investment, and Hemsedal Municipality has granted an exemption from its land-use plan, Hafslund said. Environmental impact will be limited, with most permanent land use occurring in already developed areas, according to Hafslund.
Measures such as low-carbon concrete and the use of electric machinery are expected to reduce project-related greenhouse gas emissions by around 22 per cent.
