The Sultartangi HEP consists of an embankment dam east of the Sandafell hill where the Þjórsá and Tungnaá rivers were dammed in 1982-1984, one kilometer upstream of their confluence. A spillway equipped with five rubber gates is located at the southeast end of the dam and a bottom outlet with a gate structure is located at the west end. Upstream from the bottom outlet a short headrace canal leads the water through a headrace tunnel in the Sandafell hill towards a surge basin on its southwestern side.
From a power intake downstream of the surge basin the water goes through two steel penstocks to the powerhouse which is above ground level but excavated into the hillside. A tailrace canal is excavated from the powerhouse along the right river bank and into Þjórsá river upstream of the intake structure of Búrfell power station.
The substation is equipped with gas insulated switchgear (GIS) and is linked to 220 kV transmission lines to Hrauneyjafoss station and to a substation in Hvalfjörður. The power station is connected via gateways to the dispatch control in Reykjavík from where the station is controlled and supervised. The protection relays are mostly digital with data communication links to the respective control system. The buildings have conventional lighting systems, telecommunication wiring system, fire alarm and intrusion alarm systems.
Verkís services was feasibility study, project planning, economic study, tender documents, civil work design, mechanical systems design, electrical systems design, environmental impact assessment, supervision, commissioning and startup.