Grunnåi power plant is located in Seljord Municipality in Telemark County and is part of the Skien watercourse power plant system.

Ownership: Statkraft is an indirect co-owner through its 66.62 per cent ownership in Skagerak Energi AS
Production: 48 GWh
Power: 14.9 MW

The plant has a very limited regulation capacity, making it a run-of-river power plant. The reservoir of about 25 cubic metres is emptied after just over an hour at full production.

The turbine is a five-nozzle Pelton model which is regulated by the water level in the intake reservoir and its inflows.

The power plant was commissioned in 2006, and uses a height of fall of 387 metres.

The plant has an installed capacity of 14.9 MW and an annual production of 48 GWh.

Through its majority ownership in Skagerak Energi AS, Statkraft is co-owner of this power plant. Skagerak Kraft AS, a wholly owned subsidiary of Skagerak Energi, is responsible for daily operations, and manages the licences and obligations in terms of river management and regulating of the watercourse.