Transmission system operations

There were no permanent faults this year due to weather conditions but less energy passed through the system than in 2015, due to the reduced energy consumption of curtailable load consumers (non-firm users). The operation of the grid was generally successful and grid interruptions, faults and energy not served were reduced considerably between years.

The reduction of energy delivered to non-curtailable (firm users), due to unforeseen grid disturbances, was therefore only approx. 170 MWh and the calculated power outage was approx. 5 minutes, or the lowest recorded level in the last ten years. This performance is comparable to what is happening elsewhere in the Nordic countries and across Europe and can mostly be attributed to favourable weather conditions, better systems protection and increased smart grid technology.

Landsnet is pleased to be able to offer priority consumers such a reliable electricity supply. However, this is unfortunately the exception rather than the rule as the Icelandic transmission system has far fewer and weaker connections than comparable systems in Europe.

Operational disturbances in the transmission system

Calculations on ‘outage minutes due to grid disturbances have been used to measure the reliability of the Icelandic grid since 1987. Our objective is to keep the number of outage minutes experienced by priority consumers (firm users) below 50 per year.

The total number of unforeseen grid disturbances decreased from 95 in 2015 to 72 in 2016, or 16% above the average of the last 10 years. The number of faults also decreased significantly between years with a total of 85 in 2016, compared with 123 in 2015.

Skerðingar notenda á skerðanlegum flutningi eru ekki taldar til straumleysismínútna og eru því ekki taldar með í þessu grafi

The reduction of energy delivered to priority consumers due to unforeseen grid disturbances was therefore only approx. 170 MWh and the calculated power outage was approx. 5 minutes, or the lowest recorded level in the last ten years.

However, the outage minutes for priority consumers (firm users) does not provide an accurate overview of the reliability of the grid as the volume of reserve power used during disturbances and curtailments to curtailable load consumers (non-firm users) also need to be taken into account.

Unforeseen grid disturbances are classified according to severity and the colour indicates the severity level of each event or incident. An overview of the main disturbances that caused a reduction in the supply of electricity to customers can be found in the Performance Report 2016.

Security of supply

Increased strain on the transmission system and the rise in grid interruptions has resulted in the use of back-up energy and curtailments to non-firm users. However, smart grid solutions and rapid response times have minimised or eliminated absolute outage to priority consumers and helped to achieve last year's goal on the security of delivery, despite a large number of interruptions. The number of outage minutes for 2016 would be much higher or approx. 34 minutes, without access to a back-up power supply and curtailment measures to non-firm users.

Peak load

The highest peak in power fed into the transmission system was recorded on the 29th of November, reaching 2,291 MW, which is 0.44% lower than in the previous year. The total system demand in 2016 was 17.8 TWh, or a total increase of 1.47% between years. Transmission losses totalled 360 GWh.

Exceeding security limits

We continuously monitor transmissions via defined transmission cuts or bottlenecks in the grid (see map) to minimise the impact of disturbances without compromising the transmission capacity.

Defined transmission cuts and security limits
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Grid disturbances increase the risk of an outage when the level of transmission through a cut nears or exceeds security limits (80%). The figure below shows that grid operation exceeded the security limits for a large part of the year. Landsnet’s Control Centre must require generators to change their generation plans under these circumstances, i.e. issue dispatch instructions, and sometimes enforce prolonged curtailments in certain regions. This is problematic for all those connected to the grid.

Mitigation measures

Our Control Centre is technologically advanced in energy management and grid operation matters. Our team is specifically trained to assess grid performance and operational risks in accordance with the correct procedures.

Future smart grid solutions were assessed this year as these could ensure the rapid curtailment of load for non-firm users. They could also improve the regional load balance through the load management of aluminium plants and other industrial loads and control the splitting of the grid into separate components during disturbances to ensure operational security.

Communication routes were redefined according to their level of importance and equipment was updated to meet increased management and security requirements.

Extensive work was also carried out on preparation measures for projects beginning in 2017. These include a smart grid in the south of Iceland (in connection with the voltage increase to the Westman Islands), a smart grid in Reykjanes, load management for an energy intensive user in the southwest and the upgrade of smart grid equipment in east Iceland in connection with the European research project Migrate.

Preparations are also underway for ‘fast control’ in connection with the control of generating units during disturbances, as well as continuous weather monitoring and prevention measures in cooperation with our customers. This will ensure targeted responses designed to minimise the impact of weather- related disturbances.

Strengthening the transmission system

A significant increase in the use of backup power during grid interruptions and curtailment measures (non-firm users) shows that the transmission system is widely overloaded.

The security of the grid would be well below the criteria generally used to assess the reliability of transmission systems without readily available access to back-up energy and the aforementioned curtailment measures.

The grid provides the whole of Iceland with electricity and its infrastructure must be strengthened to continue the provision of this vital service. Smart grid solutions and the increased use of reserve power are temporary solutions which do not solve the grid’s capacity problems or ensure its long-term reliability.

IT and telecommunications

IT and telecommunications are an increasingly important factor in Landsnet’s operations and the transmission system as a whole. We updated key systems, improved telecommunications, safety and security and brought new energy management system terminals into service.

Software system for the regulating power market

The development of a new software system for the regulating power market was mostly completed this year and became operational in the beginning of 2017. The system manages tenders and bids and sends control values to Landsnet’s Energy Management System to maintain balance in the electricity system. The project was tendered out in the European Economic Area and was awarded to the software company Kolibri.

Security and telecommunications

Landsnet is committed to ensuring the security of its software and IT systems, which are integral to the transmission system’s operational security. The assessment of security matters in relation to the Energy Management System and control equipment and subsequent improvements are a part of our every day operations, as is the safety and security training of the personnel resposible for the aforementioned systems.

Our Control Centre’s Wide Area Monitoring System plays an increasingly important role in the daily management of the grid. The transfer of electronic communications equipment (PMU) to a closed electronic communications network, in cooperation with the company Orkufjarskipti, was also carried out this year and should reach completion in 2017.

The telecommunications network for Orkufjarskipti in Reykjanes was strengthened during the year. A fiber optic cable was built between Fitjar and Hamranes, which allows the control centre to develop real-time controllers based on much higher data levels, ensuring faster and more secure communications.

Landsnet’s Energy Management System (EMS)

The EMS terminal units at Brennimel and Korpa were renewed this year and the control equipment in the new substations in Akranes and in Helguvík was connected to the system. The next upgrade of the EMS was also prepared.

Research and innovation

Research on energy security matters in Iceland

Landsnet and the National Energy Authority asked the MIT-EI (Massachussetts Institute of Technology – Energy Initiative) and the Comillas Pontifical University in Spain to conduct research on the “Electricity security of supply in Iceland” and to answer the question of “How to ensure long-term security of electricity supply in an economic manner” by 2030.

The research team conducted an extensive investigation on the current status of the security of the national electricity supply and offered various solutions for improvement including the strengthening of the transmission system, investment in new hydropower, geothermal power and wind power stations, the use of diesel and gas storage stations as well as the construction of a sub-sea cable connection to Europe. Proposals were also put forward with regard to administration and legislation as the leader of the project (Dr José Ignacio Pérez Arriaga) is one of the world’s greatest experts in this area. The project began in 2015 and the two universities cooperated with steering and project committees from Landsnet, Landsvikjun and the National Energy Authority. The final report is already available online.


Landsnet has been an active participant in the GARPUR (Generally Accepted Reliability Principle with Uncertainty Modelling and through Probabilistic Risk Assessment) European research project. The aim of the project is to maintain “power system performance at a desired level, while minimising the socio-economic costs of keeping the power system at that performance level.” The four-year project received an ISK 1.2 billion grant from the EU’s 7th Framework Programme for Research in 2013.

The second part of the project focuses on the testing of a new methodology with the participation of European TSOs, under Landsnet’s leadership. Landsnet’s work on assessing the reliability of the system in real-time is progressing well. The assessment is detailed as testing must be as close to the system’s real-time management as possible, involving large quantities of data on reliability, customer costs due to electricity shortages and real-time weather data.

GARPUR’s key objective is to revolutionise the prevailing methodology in grid reliability calculations and develop new and more effective indicators to enable European TSOs to better deal with the substantial changes that have taken place in the development and operation of electricity systems in Europe and work on their further development.