Vattenfall and SwifterwinT are to start dismantling the 28 turbines that make up the almost 17MW Irene Vorrink wind farm in the water along the IJsselmeerdijk north of Lelystad, Netherlands, and replace them with two rows of 12 machines totalling 132MW.
The new turbines will be located 500 and 1500 metres further into the IJsselmeer as part of the Windplanblauw project, Vattenfall said.
Fourteen machines will be owned by Vattenfall and 10 by SwifterwinT.
Construction of much larger turbines so close to the dike is no longer permitted for reasons of dike safety, Vattenfall said.
Vattenfal operational manager Herre van der Meulen was involved in the construction of the wind farm in 1997 and later became the maintenance manager.
He said: “The wind turbines built at the end of last century have a shorter service life than the current generation of wind turbines. Developments in this area are moving at a rapid pace.
“But these wind turbines have worked fantastically for all these years without many problems. We only had to overhaul all the gearboxes once.”
The dismantling of the turbines and the construction of the new wind farm will be supervised by Matthew Adam May, who works in Vattenfall’s construction management unit.
He said: “Starting in early March, we will work on one wind turbine every day to prepare it for easy dismantling as much as possible.
“We first shut down the turbine and then remove as many bolts and electric cables as possible.
“All the turbines will be shut down by April, and then we will dismantle the various parts of the turbine from a barge on the water.
“That will be one per day if the weather cooperates. Once the rotor with the turbine blades, the nacelle and the tower have been removed, the bridge to the dike will also be dismantled.
“Eventually, there will only be a small part of the steel foundation (monopile) protruding above the water.
“Using special equipment, the monopile will be sawn from the inside two metres below the bottom of the IJsselmeer, and after this part is pulled out of the water the rest of the monopile and the cabling will remain in the bottom of the IJsselmeer next to the dike.”
The Windplanblauw project will see a total of 74 onshore and offshore turbines replaced by 61 larger machines with more power.
Windplanblauw is expected to be operational from 2023.