Today the laying of the submarine cable for the EstLink 2 electricity transmission connection between Finland and Estonia was started with marine cable pull-in operations in Aseri, Estonia. The marine cable will be laid in the Gulf of Finland in two stages. The new high voltage direct current connection is expected to come into operation in early 2014 and it will play an important role in the development of the electricity market in the Baltic Sea region.
The EstLink 2 HVDC (high-voltage direct current) connection between Finland and Estonia will have a transmission capacity of 650 megawatts, which increases the total transmission capacity between the countries to 1,000 megawatts. The total length of the link is approx. 170 km, some 14 km of which is overhead line in Finland, about 145 km submarine cable laid on the bottom of the Gulf of Finland, and about 12 km underground cable in Estonia.
The total budget of the project is approx. 320 million euros, which will be divided between Fingrid and Elering, the transmission system operators in the two countries, in equal proportions. EstLink 2 will receive 100 million euros in investment subsidy from the EU as part of the EU’s extensive economy recovery package.
There will be converter stations at both ends of the link, used for converting direct current to alternating current and vice versa. The interconnection will be connected to the Finnish transmission grid at the Anttila substation. In Estonia, the cable will be connected to the Estonian grid at the Püssi substation in North-eastern Estonia.
Following the manufacturing of the submarine cable in Norway, the cable is laid on the seabed in two campaigns of approximately 75 kilometres each. A single cable campaign weighs about 5,800 tonnes. The carrying capacity of the cable installation vessel c/s Nexans Skagerrak is 7,000 tonnes.
The first campaign from the Estonian coast started today, and the cable laying work in Finland outside Porvoo is scheduled to commence preliminarily in November or December 2012. The laying schedule is dependent on the weather conditions. The final jointing, testing and commissioning of the submarine cable will be done in 2013.
The laying of the cable from the Estonian coast takes about a week, as will the laying of the cable in the sea area of Finland later on. The cables will be connected at the middle of the Gulf of Finland. After the laying of the cable, it will be submerged and protected in the seabed by means of the water jetting method.
Enhanced market functioning and improved system security
The EstLink 2 HVDC connection is built so as to improve power system security and electricity market integration in the Baltic Sea region. The project has progressed swiftly. The deliveries of materials for the converter stations and their installation work started in the autumn of 2012. Most of the work for the alternating current substations, direct current overhead transmission line and underground cable will be completed before the end of 2012.
EstLink 2 in brief, and stages of the project
– Joint project undertaken by Fingrid and Elering.
– Capacity 650 megawatts, voltage 450 kilovolts.
– Link length approx. 170 km, of which 14 km of overhead line, 145 km of submarine cable and 12 km of underground cable.
– Commissioning in early 2014.
– Total costs of the project: approx. 320 million euros.
– Environmental impact study, route selections, seabed surveys, and application for various permits in Finland and Estonia. All the basic permits were obtained in 2010.
– Reinforcement of the electricity transmission grid in Estonia. Contractor Empower Oy. All reinforcement work in Estonia is completed.
– Earthwork at Anttila and Nikuviken in Finland. Contractor Konevuori Oy. The earthwork is ready.
– Substation upgrades in Finland (Anttila) and Estonia (Püssi). The contractor in Finland is Empower Oy, and in Estonia the Siemens Osakeyhtiö Estonian branch.
– Construction of HVDC (high-voltage direct current) converter substations in Finland (Anttila) and Estonia (Püssi). The contractor is a consortium of Siemens AG and Siemens Osakeyhtiö.
– Construction of the direct current overhead line in Finland from the converter substation to the terminal point of the submarine cable. The contractor is the French company ETDE.
– Manufacture and laying of the submarine cable, and construction of the direct current underground cable in Estonia from the converter substation at Püssi to the terminal point of the submarine cable at Aseri. The contractor is Nexans Norway AS.
Press Release, October 15, 2012; Image: Nexans