Dutch transmission system operator TenneT has invited tenders for provision and installation of high voltage alternating current (HVAC) cables that will connect the offshore substations at the 1.4GW Hollandse Kust (zuid) and the 700MW Hollandse Kust (noord) offshore wind farm zones to the mainland grid.
The scope of the intended contracts includes design, engineering, production, delivery and installation of 220kV AC export cables in order to connect the offshore AC platforms with the respective onshore substations. The scope may also include 220kV AC land cables.
TenneT intends to build a total of five 700MW platforms to connect offshore wind farms at Borssele and Hollandse Kust zones to the onshore grid by HVAC subsea cables.
The platforms within one area, as part of redundancy requirements, will be connected by means of a 66kV cable. Intake power from the wind farms will be 66kV, export power from the platforms will be 220kV.
Each platform will be connected to the onshore grid by two three core 220kV AC sea cable circuits and, if applicable, by single core 220kV AC land cables.
The Hollandse Kust (noord) consists of two 350MW offshore wind farm sites which will be connected to the onshore grid via one offshore substation. The offshore substation is expected to be commissioned in 2023.
The Hollandse Kust (zuid) zone comprises four 350MW wind farms and two offshore substations. The commissioning of the two offshore substations is planned for 2021 and 2022.