The Steingrímsstöd Station is the third station built in the River Sog area. The station harnesses the head where the Upper Sog drains from Lake Thingvallavatn into Lake Úlfljótsvatn. A dam was built at the outflow of Lake Thingvallavatn, with the headrace tunnel running through Dráttarhlíd, which separates Lake Thingvallavatn and Lake Úlfljótsvatn, and into an open-air surgepond above the powerhouse. The outflow from Lake Thingvallavatn is on average approximately 100 m3/s.

The station came on-line in 1959, and the installed capacity is 27 MW.