TenneT will now pay a consortium of NKT and Boskalis a total of €210m instead of €160m to install the export cable for the Borssele Beta connection in the Dutch North Sea.
The cost adjustment follows the discovery of unstable soil on the route during work on the Borssele Alpha cable contract on the northern slope of the Honte.
The unstable soil is deemed an “unforeseeable physical condition” under the terms of the Borssele Beta contract originally signed in 2017 between NKT and VBMS (which is now part of Boskalis).
TenneT said it had carried out surveys of the route previously, but these had not indicated the physical conditions of the soil.
These conditions had made it necessary to apply a “different working method” for the installation work.
Meanwhile, TenneT has awarded a contract to Next Geosolutions Europe to carry out surveys of the export cable routes of three offshore wind farm zones off the coast of the Netherlands.
The deal covers the 700MW Hollandse Kust West Beta, 700MW Ten noorden van de Waddeneilanden and the 4GW IJmuiden Ver Alpha and Beta sites.
Hollandse Kust West Alpha is not covered by the contract.
Fugro Netherlands Marine has been assigned as a back-up to conduct the work, according to the contract document.
TenneT is responsible for engineering, procurement, installation, construction and operation of the connections between the offshore wind farms and the onshore network.