Háspennukerfið

Háspennukerfið refers to Iceland’s high-voltage transmission network, the backbone of the nation’s electricity system. It transports electricity from generation plants to population centers and export points, using transmission lines, substations, and related equipment. The system links major hydroelectric and geothermal generation with cities and industrial zones, forming the bulk power path between producers and consumers.

The network comprises high-voltage lines and substations, with some submarine cables where required. Voltage levels in the Icelandic háspennukerfið are high, commonly around 132 kV and 220 kV, although exact configurations vary by project. Transmission lines, both overhead and submarine where applicable, are designed to carry large power flows over long distances and to enable rapid switching and fault isolation to maintain reliability and voltage stability.

Operation and governance of the system fall under the transmission system operator, Landsnet hf. Landsnet is responsible for planning, building, maintaining, and operating the háspennukerfið in coordination with electricity generators, distribution utilities, and the national regulator. The network employs supervisory control and data acquisition (SCADA) systems, protection relays, and protective schemes to monitor conditions, manage power flows, and ensure safe operation. Redundancy and contingency planning are integral to the design and operation of the grid.

The háspennukerfið supports Iceland’s high share of renewable electricity by efficiently delivering hydropower and geothermal output to consumers and enabling potential export opportunities through interconnections or future high-voltage links. Ongoing upgrades aim to improve capacity, resilience, and integration with evolving generation and market needs.