Windpark Fryslân onshore cable in place

Visser & Smit Hanab has laid and tested the onshore HV cable connecting the transformer station and HV substation of the Windpark Fryslân nearshore wind farm in the Netherlands.

Approximately 23 km of 110 kV cable was laid from Breezanddijk through the Afsluitdijk and along the A7 motorway to Bolsward, from where 32 km of cable continues to the Oudehaske high-voltage substation near Heerenveen.

According to TenneT, this 55 km of cable is the longest underground cable connection constructed in the Netherlands. 

Because the route mostly runs along a narrow roadside strip, the cables are partly above each other. 60% was laid in open excavation, while the rest was drilled under waterways and motorways, the transmission system operator said.

The cables were welded together at Bolsward and tested. The weld, or the so-called terminal block, between the high voltage cables is a temporary application. 

TenneT is preparing for a new high-voltage substation west of the De Marne industrial estate near Bolsward. By connecting existing and new cable connections, this will create an extra ‘ring’ in the West Frisian high-voltage grid from 2023.

“The construction was complex, partly because the connection is on the verge of the highway with little space and a lot of traffic. The project as a whole was successful and safe. No incidents and accidents. That’s the most important thing,” said Tim Christiaans, Project Manager at TenneT.

Windpark Fryslân will comprise 89 Siemens Gamesa 4.3 MW turbines located in the IJsselmeer Lake.

Once fully commissioned, the 382.7 MW project will become the largest wind farm in the world installed in inland fresh water.