Ulla-Førre

Ulla-Førre is a hydropower complex in Southern Norway. It is situated along the borders of the municipalities of Suldal and Hjelmeland (in Rogaland county) and Bykle (in Agder county), Norway. It has an installed capacity of approximately 2100 MW, and the annual average production is 4.45 TWh (1987–2006), while its reservoir capacity is about 7.8 TWh; at full production, it can last seven to eight months. The complex includes the artificial lake Blåsjø, which is made by dams around 1000 m above the sea level. The hydroelectric power stations in the complex are Saurdal, Kvilldal, Hylen and Stølsdal, operated by Statkraft.

Blåsjø
Blåsjø is the tenth largest lake in Norway by area. It is located in the municipality of Bykle in Agder county and the municipalities of Hjelmeland and Suldal in Rogaland county. The lake is about 20 km west of the village of Bykle. It has a surface area of 84.48 km2. Its surface swings between 930 and 1055 m above sea level depending on seasonal weather and power consumption, and it has a shoreline of about 200 km. At the highest regulated water level, Blåsjø contains 3,105,000,000 m3 of water.

Kvilldal Hydroelectric Power Station
The Kvilldal Power Station is a located in the municipality of Suldal. The facility operates at an installed capacity of 1,240 MW, making it the largest power station in Norway in terms of capacity. Statnett plans to upgrade the western grid from 300 kV to 420 kV at a cost of NOK8 billion, partly to accommodate the North Sea Link cable from Kvilldal to Blyth, UK.

Saurdal Hydroelectric Power Station
The Saurdal Power Station is a hydroelectric and pumped-storage power station located in the municipality of Suldal. The facility operates at an installed capacity of 674 MW (in 2015). The average energy absorbed by pumps per year is 1189 GWh (in 2009 to 2012). The average annual production is 1335 GWh (up to 2012).

Hylen Hydroelectric Power Station
The Hylen Power Station is located at the bottom of Hylsfjord in Suldal. It operates at an installed capacity of 160 MW, with an average annual production of 583 GWh. The plant exploits water through a tunnel from the lake Suldalsvatnet.