Sog Hydroelectric Stations
Ljósafoss Station
Ljósafoss Station, the first phase of the River Sog developments, went on line in 1937 using two turbines with a combined installed capacity of 8.8 MW. A third turbine with a capacity of 5.5 MW was installed in 1944. A dam was built at the outflow point of Lake Úlfljótsvatn, raising the water table by one metre. The station is located on the riverbank east of the Ljósafoss waterfall.
Írafoss Station
Írafoss Station harnesses two waterfalls, Írafoss and Kistufoss, in the lower part of the River Sog, with a combined head of 38 m. A dam has been built above creating a small intake pond with water table at the same level as Ljósafoss tailwater. Intake structures are situated on the east bank of the river, where the water enters a steep pressure shaft to the three Francis untis in the underground powerhouse. From there, the water flows along an almost tailrace tunnel and re-enters the river below Kistufoss waterfall. The station went on line in 1953 with two 15.5 MW generating units, and in 1963 a third 16.7 MW unit was installed.
Steingrímsstöd Station
Steingrímsstöd Station went on line in 1959 utilizing the 20.5 m head in the Upper Sog between Lake Thingvallavatn into Lake Úlfjótsvatn headwater of Ljósafoss Station. A dam was built at the Sog River outflow from Lake Thingvallavatn. The water flows through a headrace tunnel into an surge tank above the powerhouse. A shaft leads from the surge tank to two turbines with a capacity of 13.5 MW each.
Renovations 1996-2001
A complete renovation of the Sog Power Stations is in its final stage. Now these old stations produce more electricity than ever before. Because of the renovation much space in Ljósafoss Station has become vacant and will in the future be used as exhibition and educational facilities. The history of the Sog Power Stations and recent renovations are clear examples of how longlived hydro power stations and how tourism can florish together.
