Asso.subsea scores contract for Vattenfall's nearshore duo

4C Offshore | Tom Russell
By: 23/11/2021 Asso.subsea

Asso.subsea Limited has been awarded by Vattenfall for the transportation, installation, protection and commissioning of the 66 kV export and inter-array submarine cables of the 350 MW
Vesterhav Syd & Nord nearshore wind farms.

The overall system will consist of four export and thirty-seven inter-array cables, for a total of more than 70 km to be installed along a submarine route characterised by high technical challenges, including shallow water areas, boulder fields, mobile sediments, and a great variety of conditions from very soft to hard soils.


Asso.subsea will deploy its DP2 cable laying vessel Atalanti, specialised in extremely shallow water working environments, and the DP2 trenching support vessels ‘Argo’ and ‘Aethra’ for the seabed preparation and post-lay burial operations. The latest versions of the trenching machines from the AssoTrencher IV as well as the AssoJet III families, will be mobilised in order to provide the required protection of the cables along the whole submarine route.


The completion of the project is scheduled by mid-2023.


Mr. Ioannis Togias, Director of the Marine Division of Asso.subsea Limited, commented: “We are delighted for the opportunity to work with Vattenfall on a so prestigious project, after the positive experience on the Kriegers Flak boulder mitigation campaign. With more than 40 M€ invested only in 2020 for the expansion and upgrades of our fleet, we are extremely proud to be able to support Vattenfall in another fundamental step towards the energy transition”


Vesterhav Nord will have a capacity of 180 MW and will consist of 21 SG 8.0-167 DD turbines, each with a rated power of 8.4 MW. Vesterhav Syd will have a capacity of 170 MW and will consist of 20 turbines. Combined, the projects will supply electricity equivalent to the annual consumption of 350,000 Danish households. Vattenfall secured permits for the two Vesterhav wind areas in 2016 for 47.5 øre/kWh (€63.8/MWh). The two offshore wind farms will increase Danish electricity production from wind turbines by approximately 10 percent.  


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