Duge power plant is situated in the Sira watercourse on the border between Forsand and Sirdal municipalities in Vest-Agder County.
Ownership: Statkraft is an indirect co-owner through its ownership in Skagerak Energi, Agder Energi and Sira-Kvina kraftselskap
Production: 248 GWh
Power: 200 MW
The power plant was commissioned in 1979 and uses a height of fall of 240 metres between Lake Svartevatn and Lake Gravatn.
Lake Svartevatn, the intake reservoir for this plant, is dammed with a 130-metre-high riprap dam. This is the largest dam in the Sira-Kvina development. The water is regulated between 899 and 780 metres above sea level, and the reservoir can hold up to 1.4 billion cubic metres of water.
The plant is equipped with two vertical Francis turbines having a total capacity of 200 MW. The turbines are special in that they are reversible pump turbines that can pump water back into the reservoir through the 1 200-metre-long tailrace tunnel for storage for later production. This is done during periods of low electricity prices and high inflows to the reservoir, mostly in spring and autumn.
Construction of Duge power plant marked the completion of the fourth construction stage in the Sira-Kvina development and the full utilisation of the waterfalls in the Sira watercourse from 900 metres above sea level down to the sea.
Through its ownership in Skagerak Energi AS, Agder Energi AS and Sira-Kvina kraftselskap, Statkraft is co-owner of this power plant. Sira-Kvina kraftselskap is responsible for daily operations, and manages the licences and obligations in terms of river management and regulating of the watercourse.