Contractor NRG has started drilling under sand dunes near Velsen for the landing of sea cables for TenneT’s Hollandse Kust west Beta project.
Two electric drills have been placed on the “sand castle” on Velsen beach in the Netherlands.
In the coming weeks, both machines will drill towards each other at a depth of about 30 metres for the connection of the Hollandse Kust offshore wind farm (west Beta).
In recent months, contractor NRG has built a temporarily elevated working area on the beach of Velsen for the two drillings under the dunes.
Project leader Johannes Becker said: “With this ‘sand castle’ we eliminate the height difference on either side of the dunes.
“This way we prevent the drilling fluid, which we use to keep the boreholes open, from running out again at the lowest point.
“After we have drilled a hole, we pull an empty plastic casing pipe into the hole where TenneT’s electricity cables will soon be laid.”
TenneT will install a socket at sea next year 50 kilometres off the coast of Egmond aan Zee.
The wind turbines that energy company RWE will have built at sea in 2025 will then be connected to this.
To bring that power ashore at Velsen from 2026, contractor NBOS (combination Boskalis + Orient Cable) will install two electricity cables in the seabed next year.
Behind the dunes, these sea cables are connected underground with “large crown stones” in so-called socket pits to the cables on land.