Gotland 1, the original 20 MW, 100 kV HVDC submarine link between Västervik on the Swedish mainland and Ygne on Gotland, was taken out of service in 1986 after about 28 years of operation, with its original cable system replaced as part of the higher‑capacity Gotland 3 expansion driven by load growth on the island.
In 1970, the original Gotland 1 HVDC submarine link between Västervik on the Swedish mainland and Ygne on Gotland was uprated, with ASEA and Vattenfall increasing its transmission capacity from 20 MW to 30 MW and raising the DC voltage from 100 kV to 150 kV by installing the first commercial thyristor modules in series with the existing mercury‑arc valves while continuing to use the original mass‑impregnated submarine cable.
Gotland 1, the first HVDC Gotland link, entered commercial operation in March 1954, transmitting up to 20 MW at 100 kV over a roughly 96–98 km mass‑impregnated submarine cable between Västervik on mainland Sweden and Ygne on Gotland. The converter stations, using mercury‑arc valves developed by ASEA for the state-owned utility Vattenfall, made this the world’s first fully commercial high-voltage DC submarine transmission link.
Upgrade to access detailed cable specifications, supply chain data, projected timeline, financial analysis, and more.
Gotland 1 was the world’s first commercial HVDC submarine power link, commissioned in 1954 to connect the Swedish mainland near Västervik with the island of Gotland (Ygne/Visby area). The original monopolar installation was rated at 100 kV with a transmission capacity of 20 MW and comprised appro...
Owners
Gotland HVDC Link, Gotland 1, Gotland I, Gotlandsförbindelsen, Gotland–mainland HVDC (1954), Vattenfall/ASEA Gotland link
In 1953, the pioneering HVDC submarine cable system for the Gotland 1 link was laid between Västervik on the Swedish mainland and Ygne on Gotland. The turnkey project for Vattenfall included design, engineering, manufacturing, testing, and installation of a 96 km, 100 kV, 20 MW mass‑impregnated cable, completing the cable installation phase of the world’s first commercial HVDC submarine interconnection.
Cable installation for the Gotland 1 HVDC submarine link began in 1953, when NKT started laying the 96 km, 100 kV submarine cable between Västervik on the Swedish mainland and Ygne on Gotland under a turnkey project for Vattenfall in the Baltic Sea, with the cable in place between the converter stations by the summer of that year.
In 1950, the Swedish parliament decided to fund a high-voltage direct current transmission link between Gotland and mainland Sweden, and the Swedish State Power Board (Vattenfall) placed an order with ASEA for a 20 MW, 100 kV submarine cable system, thereby committing the necessary investment for the Gotland 1 HVDC interconnector to proceed.
In 1950, the Swedish State Power Board (later Vattenfall) ordered the Gotland high-voltage direct current (HVDC) link from Swedish manufacturer ASEA, making ASEA the supplier of the mercury-arc valve converter stations and associated HVDC equipment for the 20 MW, 100 kV submarine connection between mainland Sweden and Gotland (Gotland 1).
Vattenfall engaged NKT to deliver a turnkey HVDC submarine cable system for the first Gotland link (Gotland 1), including design, engineering, manufacturing, testing, laying and installation of a 96 km, 100 kV, 20 MW mass‑impregnated cable between Västervik on the Swedish mainland and Ygne on Gotland during the 1953–1954 project period.
In the early phase of the Gotland 1 HVDC project, before or around its 1954 commissioning, Vattenfall and ASEA carried out extensive environmental testing to determine the effects of using the Baltic Sea as the return current path on fish populations near the monopolar subsea cable between Västervik and Ygne. These tests were undertaken to assess and mitigate ecological impacts of the world’s first commercial submarine HVDC sea-return link.
Showing historic events only. Subscribe for the full timeline including projected milestones.