The U.S. is not alone in having ambitious targets for floating offshore wind. Forecasts indicate that by 2050 over 200 GW of new floating offshore wind turbines will be in operation worldwide, equating to around 13,500 units.
Damen Shipyards says that, given their size and the depths of the water in which they will be positioned, these turbines will require chains and anchors of unprecedented sizes. Even just one floating wind turbine starting to drag an anchor upwind of others could have a serious impact on the output of an entire wind farm, so the anchoring systems must leave nothing to chance. Research indicates that each turbine will require between three and six anchors, with chain diameters increasing from a typical 152 mm for a large offshore structure to upwards of 220 mm.
BIGGER VESSELS NEEDED
While the anchoring technologies will remain much the same, says Damen, the vessels required to handle them will need to be much bigger than today’s anchor handlers. And given the projected demand for their services, they will also have to be exceptionally efficient.
In cooperation with suppliers and vessel operators, Damen is now working on a new class that will be able to meet this need. As an integrated R&D, design, engineering and shipbuilding group it has all the resources needed to undertake this challenge. It even has its own anchor and chain production facility, giving it additional insights.
While there is much work to be done, initial feedback from anchor handling specialists has been positive. Damen is also in discussions with other suppliers regarding new deck systems that can accelerate the loading of chain, synthetic rope, steel wire, clump weights and other possible mooring line components in port while maintaining safety, a major consideration given the sizes and weights being contemplated.
Damen says its offshore construction facility at Damen Shipyards Mangalia, Romania, will be playing a part in the floating offshore wind market development. In particular, it is well positioned and equipped to produce the large number of floating foundations on which the turbines will be mounted.
“There are many variables relating to the new vessel concept still to be assessed and explored, not least the final nature of the FOWT (floating offshore wind turbine) mooring systems,” says Damen’s business development manager offshore wind, Wijtze van der Leij. “If larger numbers of lighter anchors and chains per turbine are judged superior to fewer but larger, the vessel design will adapt accordingly. But whatever the outcome, rapid growth in the offshore wind turbine sector is just around the corner and at Damen we are working hard now on the solutions that will support that growth in ways that are both economical and sustainable.”