Major Outage

In 2020, Statnett and Energinet reported operational issues on the Skagerrak 4 (SK4) interconnector for which the underlying causes had not yet been identified. As a precautionary measure to minimise the risk of further faults on the link between Norway and Denmark, the transmission system operators decided to reduce the electrical load permitted on SK4. Consequently, the maximum transfer capacity on the overall Skagerrak interconnection was lowered from 1700 MW to 1450 MW. Due to the technical solution used on Skagerrak 4, the available capacity became asymmetric, permitting 1450 MW in the primary flow direction and 950 MW in the secondary direction, with several days required to reverse which direction is primary. Statnett and Energinet indicated they were pursuing multiple measures to manage and, where possible, increase capacity, including assessing the socio-economically optimal primary direction, working to raise capacity in the secondary direction, and taking samples of the existing SK4 onshore cable on the Danish side to assess its condition. They stated that the market would be kept informed of decisions and any impact on trading capacity via NUCS reports.