Construction on Undersea Cable between Muhu Island and Mainland Starts

This week, Empower AS began preparation work to install the new Virtsu-Võiküla 110 kV undersea cable in the Great Strait on Elering’s order.

Among the preparations is removing one of the existing 35 kV undersea cables from the sea. After removing the old cable, the new 110 kV cable will be laid on the seabed during the summer. The removal of the old cable and laying of the new cable will be carried out by a special cable ship from Finland.

“The new cable will significantly increase the security of supply of the islands and will allow them to cope with potential increases in electricity consumption. The transmission capacity of the new cable is higher than that of the six existing lines put together,” explained Elering’s Chairman of the Board, Taavi Veskimägi.

The total length of the new cable is approximately eight kilometres, out of which seven kilometres will be placed at sea and one kilometre on the mainland. The new cable is more environmentally friendly than the current one being replaced due to its polyethylene insulation (XLPE) instead of oil-impregnated paper. The new cable will be buried under the sea floor to reduce the risk of damage from anchors, ridged ice, and other external factors.

Under the plan, the deadline for the entire Virtsu-Võiküla undersea cable installation project is this autumn. Based on the public procurement, the cost of construction work is 9.4 million euros without purchase tax.

At the moment, six old 35 kV undersea cables supply the islands of western Estonia, though their reliability does not meet modern requirements. In the future, Elering is planning on installing another 110 kV undersea cable between the mainland and Muhu as well as another new connection between Muhu and Saaremaa. At the moment, both overhead lines that supply Saaremaa and Hiiumaa are located on the same pylons on the dam of the Small Strait. If some of these pylons should break due to weather conditions or other reasons, this could result in electricity outages for dozens of hours.