The security of electricity supply to the islands will be further improved
In autumn 2020 we energized the 110 kV submarine cable of the Suur Väin. The project, which started with a construction contract concluded with Elering AS at the end of 2018, was completed in cooperation with Merko Infra. During the works we replaced two old 35kV cable lines between Rõuste substation on the mainland and Tusti substation in Muhumaa with a new 110kV submarine cable. The total length of the cable line is almost 11 kilometres, including the submarine cable of 9.7 kilometres. The cable was made in Pikkala cable plant of Prysmian, Finland, and installed to sea by using a special vessel. The total weight of the cable is about 650 tons. We built a new 110kV section to connect the line of Rõuste substation and dismantled and utilized the existing 35kV cable lines.
The capacity of the Suur Väin cable is 520 amperes and the submarine cable has been connected in three phases into one cable. The cable has a diameter of 190 millimetres and weight of 67 kilograms per meter. The submarine cable was installed to sea as one long cable, i.e. without straight joints. A 48-fiber optical communication cable has also been installed inside the new cable. The cable was flush mounted to the seabed in the strait to reduce the risk of damage by anchors, ice and other external factors. The new submarine cable will improve the security of electricity supply in Saaremaa and Hiiumaa.