Landsnet owns and operates all major electricity transmission lines in Iceland. The bulk transmission system (“the grid”) consists of power lines with voltages of 66 kV and higher, some 33 kV lines and all major substations in the country.
The Icelandic electricity system’s highest operating voltage is 220 kV. A large part of the system operates at 132 kV, but some parts have voltages of 66 kV and 33 kV. The newest transmission lines in south-west Iceland were built as 420 kV lines, but operate at 220 kV.
At the start of 2008, the estimated value of Landsnet’s transmission system was approximately ISK 80 billion at initial value and ISK 46.6 at book value. The lion’s share of the system’s value is in transmission lines and substations.
All power stations with a capacity of 7.0 MW and higher must be connected to the grid. Power is fed into it at 19 locations at present. The grid supplies electricity to distribution system operators at 57 locations and to power-intensive industries at four locations around the country. The distributors then transmit the power onwards via their own networks to the consumer.
Growth and maintenance
The transmission system has grown substantially since Landsnet’s inception. Investment has been made in increased transmission capacity to meet growing electricity demand from power-intensive industries.
We are obliged to ensure the preparation of forecasts of electricity demand as well as a long-term plan for the grid’s development. Such a five-year forecast is published annually. We also have defined standards for operational security as well as for the assessment of transmission limits and co-ordinated adjustment of protection systems.
Our workforce has extensive experience in the development and maintenance of transmission infrastructure. Maintenance is threefold: routine, condition-based and general maintenance. Additional checks and maintenance are carried out when necessary, such as after very severe weather.