The Randstad Noordring will also ensure security of supply for Amsterdam, Rotterdam, The Hague and Utrecht, the TSO stated.
So far, it has commissioned 38 power masts, installed a further 78, and is currently working on 35 for an eventual total of 151 along an approximately 65km stretch between Bleiswijk and Beverwijk.
Tennet expects the connection to be completed in the third quarter of 2019.
Most of the connection will be laid above ground, but about 20km will be underground, the TSO stated.
The underground sections will consist of five routes of 12 parallel cables. With these extra routes, the total length of the 50kg/m cable is 240km, Tennet added.
These cables will, on average, be buried two metres underground, the operator stated.
However, where this is not possible — for example, when crossing a watercourse — the cable will be buried at depths of between 10 and 35 metres.
The technical universities of Delft and Eindhoven will monitor the cables’ behaviour as part of an international research program with Tennet and Austrian network operator APG (Austrian Power Grid).