Skagerrak 4
Cross BorderOperational
NODK
700 MW500 kV240 km2014Also known as:SK 4, SK4, SKAGERRAK IV
Status:Operational
Capacity:700 MW
Project Company:
Statnett SF
Type:cross border
Website:www.statnett.no
Skagerrak 4 is a 500 kV HVDC interconnector linking Kristiansand (Norway) and Tjele/Bulbjerg (Denmark) to increase transmission capacity and facilitate trade between the Norwegian hydro-based system and the continental/Nordic markets. It was developed jointly by the two national TSOs, Statnett (Norway) and Energinet.dk (Denmark). Technically, SK4 is a VSC-HVDC pole...
Supply Chain (4)
Project Timeline (12)
2020Regulatory OtherStale
In 2019, Energinet and Statnett submitted an application and implementation plan to introduce implicit handling of grid losses on the Skagerrak interconnector, including Skagerrak 4, with scheduled tasks through 2019, functionality testing from November 2019 to January 2020, and a subsequent “Go Live” of the new loss-handling method using a 3.8% loss factor. This change is intended to modify how losses are accounted for in market operations on the interconnector, delivering estimated annual socio-economic gains of about EUR 0.9 million for Norway and EUR 2.3 million for Denmark once implemented.
26 Mar 2019Regulatory Other
Licence: Methodology change for implicit handling of grid losses on the Skagerrak HVDC interconnector
On 26 March 2019, transmission system operators Energinet and Statnett submitted a joint application to introduce implicit handling of grid losses on the Skagerrak HVDC interconnector, based on a Nordic TSO analysis using a 3.8% loss factor and simulations over February 2014–May 2015. The application outlines the socio-economic impacts of the change and a staged implementation plan, including required agreement and IT/communications updates and functionality testing ahead of go‑live.
24 Mar 2015Capital Support Awarded
The Skagerrak 4 interconnector project received EU funding support totalling 23.8 million DKK from the Trans‑European Energy Networks programme, of which 16.3 million DKK had been disbursed by the time of reporting. This grant contributes to the approximately 3.3 billion DKK construction budget for the 240 km, 700 MW cable between Denmark and Norway, which increases interconnector capacity to 1,700 MW and enhances Denmark’s ability to exchange wind and hydroelectric power with its Nordic neighbours.
kr23.8M (grant)
12 Mar 2015Commercial Operations Full Power
On 12 March 2015 Skagerrak 4 was officially inaugurated by Danish and Norwegian dignitaries, with Prysmian and the TSOs Energinet.dk and Statnett announcing that the 700 MW HVDC interconnection between Kristiansand (Norway) and Tjele (Denmark) was ready for commercial operation. This fourth Skagerrak link, built entirely as cable on land and subsea, increased total transfer capacity between the two countries to about 1,700 MW and supports greater exchange of renewable hydro and wind power in the Nordic electricity market.
2015Onss Commissioned
In 2015, Hitachi Energy (then ABB) completed commissioning of the Skagerrak 4 HVDC Light converter link and the associated upgrade of the Skagerrak 3 classic HVDC pole, creating a 700 MW, 500 kV bipole configuration that increased total transmission capacity between Kristiansand, Norway and Tjele, Denmark to about 1,700 MW.
1 Oct 2014First Power
Skagerrak 4, the 700 MW HVDC interconnector between Norway and Denmark, entered its test phase on 1 October 2014, indicating initial energisation and first power transmission on the link. The system then continued testing through late 2014 before moving towards full operational status.
19 Oct 2011Capital Support Awarded
The Nordic Investment Bank approved a NOK 1,300 million (EUR 168.1 million) 16‑year loan to Statnett SF to partially finance the Skagerrak 4 HVDC cable between Norway and Denmark and the upgrade of the Oslofjord cable. Statnett and Energinet.dk are investing in the new 700 MW, 240 km Skagerrak 4 interconnector to improve security of energy supply, increase cross‑border power exchange, and support greater use of Norwegian renewable generation and Danish wind power, with project completion scheduled by the end of 2014.
€168.1M (debt)
Jan 2011Cable Supplier Selected
In January 2011, Energinet.dk awarded Prysmian Group a contract worth about €40 million to supply, joint, and test approximately 92 km of 500 kV mass‑impregnated underground HVDC land cable and accessories for the Skagerrak 4 interconnection on the Danish side, providing 700 MW of transmission capacity.
2011Converter Supplier Selected
In 2011, Statnett and Energinet.dk awarded Hitachi Energy (then ABB) the Skagerrak 4 converter project, comprising a fourth HVDC link using HVDC Light technology operating in bipole mode with Skagerrak 3, including new 500 kV, 700 MW converter stations and a control system upgrade for the existing Skagerrak 3 link.
1 Jan 2011Onshore Construction Start
For the Skagerrak 4 HVDC interconnector between Kristiansand in Norway and Tjele in Denmark, Energinet.dk and Statnett commenced the construction phase on 1 January 2011 after obtaining all major approvals from the authorities by the end of 2010. This marked the start of physical works to add a fourth 700 MW, 500 kV DC cable alongside the existing three Skagerrak cables, increasing the interconnection capacity by 700 MW.