Vattenfall starts construction of 1.5 GW Hollandse Kust Zuid offshore wind farm

Swedish utility and energy developer Vattenfall AB has started the construction of the 1.5 GW Hollandse Kust Zuid (HKZ) offshore wind farm project located in the Dutch waters in the North Sea. 

The construction works for Hollandse Kust Zuid start with the installation of monopile foundations. Each foundation is designed specifically for the location where it will be installed. The heaviest and largest monopile weighs 955 tons and is 75 meters long, while the lightest and shortest foundation still weighs 735 tons and is 62 meters long. The monopiles will be installed in water depths varying from 17 to 28 meters.

An installation vessel transports the foundations to their offshore location and positions itself at the exact location. The ship's crane then lifts the monopile into the water and lowers it until it reaches the seabed at a depth of 17 to 28 meters. Once the foundation is in position on the seabed, a hydraulic hammer is used to drive the pile to the desired depth.

Vattenfall is building Hollandse Kust Zuid together with its recently announced partner BASF. The wind farm will be located approximately 18 kilometers off the coast of The Hague and Zandvoort, with the furthest turbines located 36 kilometers offshore. When fully operational, Hollandse Kust Zuid will be the largest offshore wind farm in the world.