Conceptual development of an offshore wind farm and technical assessment of a 10-MW base-model floating wind turbine

An overall feasibility analysis of a floating offshore wind farm off Gran Canaria is carried out. Chapter 1 defines reasons for floating wind energy as a vector for the energy transition as well as considerations and examples. Then, Chapter 2 introduces the project and motivations that took the author into this project and proceeds to focus on the necessary steps to carry out the wind resource assessment (Section 2.4) of the floating wind farm selected for the lease area designated. This involves the creation of the topographic map of the area as well as the implementation of the wind climate into the WAsP software, where it is analyzed to obtain the required predicted and extreme wind climates. Afterwards, the wind farm design (Chapter 3) is conducted. For that, the DTU 10 MW wind turbine is selected. A suitable wind farm layout is designated after comparing three different options, based on technical reasons. The technical losses and uncertainty levels were evaluated and the net annual energy production along with other important parameters obtained. A sensitivity analysis was then done and afterwards, the grid connection strategy of the wind farm made. This leads to the final selection of the FOWT (floating offshore wind turbine) in Chapter 4; additionally, information about the NAUTILUS substructure and other real-life FOWTs are presented. Consequently, Chapter 5 presents the mooring design required for the time-domain simulations in FAST software and, afterwards, moves onto the analysis of the radiation-diffraction loads on the platform extracted from frequency-domain simulations in WAMIT software. This entails a fluid-structure interaction analysis of such loads that will serve to evaluate the platform’s structure in Chapter 6. Finally, in Section 5.5 the seakeeping simulations of several cases in the presence of wind and waves is presented. From that, we can move on to Chapter 6, which goes through a linear and elastic structural analysis of the NAUTILUS platform with the beam-model software Steel from Bureau Veritas; this leads to the yielding check with the software and then to the buckling check following Rules from the same Classification Society. An elastic-linear analysis of the critical parts that suffer the highest loads in the platform (transition piece and fairlead connections) is afterwards conducted with ANSYS software to define their structure. Towards the end of the master’s thesis Chapter 7 treats the sustainability issues of the project. An economic analysis (Section 7.1 of the wind farm project that estimates capital, operational and decommissioning expenditure is conducted. Furthermore, all the main economic parameters have been calculated, in addition to a sensitivity analysis performed on the most relevant inputs. Then, the societal context (Section 7.2) is borne in mind. A stakeholder analysis is carried out in order to address the main impacts the project has on society and how to address them with mitigation strategies. Finally, the environmental impact assessment (Section 7.3) of the wind farm follows with emphasis on the marine species, flying species and marine substrate affected by the construction, operation and demolition of the wind farm. Furthermore, a brief overview of the permitting process for a Spanish wind farm is given. The main conclusions of the master’s thesis with future work ideas can be found in Chapter 8