|The demand for renewable energy in Europe is increasing. The largest potential is offshore wind energy where future wind farms consist of floating wind turbines. The wind is stronger at sea and the floating wind turbines must increase in size to generate more energy. These factors make the operation process challenging and costly without strategic planning.
This work aims to identify the logistic planning of transporting and installing floating offshore wind turbines to an offshore wind farm in Sørlige Nordsjø 1 in the North Sea. A Mixed-Integer Linear Programming (MILP) model is developed to optimize the total costs of operating from five different assembly sites on the west coast of Norway, where different vessel strategies are analyzed together with the installation process. Assembly sites are areas where mobilization and docking of vessels can take place and storage of partly assembled turbines. Vessel strategies are different methods of transportation from these sites to the final wind farm site. More on both concepts will be discussed in greater detail later. Weather windows and weather constraints are considered in the model to determine when operations can take place. Data for cost, vessel strategies, and operation time concerning the weather are implemented in AMPL, where several tests of the model are performed to determine the optimality of these. The main test consists of a different number of installed wind turbines in a time horizon of 30 days. This time horizon refers to the complete lifetime of our project, from parts or partly assembled wind turbines at assembly sites to the final finished wind farm at sea. Two additional tests where several assembly sites must be in use are also implemented. The main test and the two additional tests are analyzed in relation to each other, and total costs are compared between them. The results are valuable for future projects for the development of floating offshore wind farms, from a technical and economical view. We found that operating from one assembly site with transportation of partly assembled wind turbines is most optimal when parameters such as cost, weather, and time are considered.
Norway needs more investors for future development of floating wind farms, but to realize this, the total costs of projects must decrease. In this work, our model could help accelerate future project developments through better logistical strategic planning to save large costs.