Hólasandur high-voltage line 3 officially put into operation
Hólasandur High-voltage line 3 was officially put into operation at a ceremony in Akureyri September 30th together with two new 220 kV substations at the end points of the line. The aim of the project is to improve energy efficiency, increase transmission capacity and ensure the stability of the electricity system in North and East Iceland.
Verkís took care of i.a. project supervision with the laying of the underground-cable part of the line and the construction of the substations, together with the design of their electrical equipment.
Hólasandur HIgh-voltage line lies within four municipalities; Akureyri, Eyjafjörður-county, Þingeyja-county and Skútustaðir-county. It is divided into a 62 km overhead line section and a 10 km underground-cable section. In addition to the line, new 220 kV substations have been being built at Hólasandur and at Rangárvellir near Akureyri, but they are both part of a new generation of indoor type digital substations with gas insulated (GIS) electrical equipment..
The line route mostly lies along the line route of the existing Byggðalína, but from Laxárdalsheiði to Hólasandur the line route is new. The line was strung across Laxárdalur for about 1 km long span in order to minimize environmental impact, being one of the longest line span in the country. The first 10 km of Hólasandur HIgh-voltage line 3 from Rangárvellir in Akureyri were laid as an underground cable, but it ends in the land of Kaupangur in Eyjafjörður-county t where the overhead line takes over. Two sets of 1,600 mm2 cables were laid. A new cable-stayed bridge over Glerá was built due to the cables, but it is also used as a horse-riding bridge.
Verkís worked on the over-all design of the substations at Hólasandur and Rangárvellir and the tender design for all their electrical equipment. Verkís supervised also the design of electrical equipment contractors and provided assistance during the tendering and construction period of the substations.
Verkís supervised as well the construction of the substations and the installation of their electrical equipment and testing. Then Verkís supervised the extensive and complex work of earthworks and the laying of two sets of underground cables in Hólasandur HIgh-voltage line 3 and the construction of a cable-stayed bridge over Glerá.
With the construction of Hólasandur HIgh-voltage line 3 and the substations at Hólasandur and Rangárvellir, a 220 kV voltage connection has been established between Fljótsdalur and Akureyri and thus significantly increased transmission capacity in the area, but three power plants are directly and indirectly connected to the system.
Verkís congratulates Landsnet and all of the country’s citizens on this important step in the development of a new generation of Byggðalína and associated substations.