The scalability of floating wind installations in Norway and beyond
Abstract
Offshore wind energy has recently become a big industry in many countries [89]. However, offshorefloating is still at the beginning of its commercial use, and the number of projects underdevelopment has increased. Future offshore wind projects are expected to increase in size, usingwind turbines with larger design capacities, be in deeper waters, and further offshore. As aresult, ports need to be modified to handle the larger turbines and substructures [33, 6]. TheNorth Sea has great potential for offshore wind parks in intermediate deep waters; therefore,many projects are planned in this area. However, this study focuses on developing an offshorewind park with turbines mounted on a spar substructure. In particular, this thesis investigatesthe development of the Utsira Nord project in Norwegian waters with Wergeland base as an assemblingbase and gives a short outlook of a project area in Scottish territories.Different parameters such as storage capacity, scaling up infrastructure in terms of the numberof cranes and vessels, and shift rotation has been analyzed and compared. Further, the sizeof the wind turbine has been scaled up, as well as the installation from different ports for twodifferent sites. Analysis showed that the crane has a major influence on the costs, and its usageshould therefore be reduced to a minimum. Having sufficient storage capacity is essential forthe efficient usage of the crane. However, in our simulations, crane and storage capacity didnot influence the completion time significantly. Similar reductions in the completion time canbe obtained by using more or faster tug and anchor handling vessels (AHV), but using morevessels did increase the cost. Having more tugs is more profitable in combination with an increasedstorage capacity. Nevertheless, using faster tugs gives an improved cost-benefit whena smaller storage capacity is available. When comparing the installation for a site from two differentports, it was assumed that both ports have the same infrastructure. The port closest tothe project site has a big advantage as the installation from that port takes less time due to thelower transit times. However, it is important to note that the port in Scotland does not have deepwater close to shore or the same crane and storage space that Wergeland Base has in Norway.Norway’s unique geography means that we have deep water and sheltered wave conditions thatare ideal for the assembly of deep and shallow draft floating wind turbines.