Optimization of export electrical infrastructure in offshore windfarms : Developing an electrical export module in a front-end holistic model for offshore wind plant optimization

Sammanfattning: The work focuses on the methods used to develop one particular sub-part of a computer tool for optimizing the final cost of energy in offshore wind parks : the linking infrastructure for bringing electrical power ashore. The thesis is the outcome of a 6-month cooperation with AREVA Wind, within the Wind Plant Solutions department, and is based on previous work done by AREVA, their proprietary database, as well as on publically available technical data. Exporting power from an offshore electrical substation down to the grid connection point is nowadays a critical bottleneck in the development of offshore wind energy, where project optimization and cost reduction are for many viewed as powerful levers capable of increasing dramatically its competitiveness on the electricity market. The approach and methodology used to develop the model, along with challenges and difficulties encountered are exposed. The necessary outputs are defined, the related equations are carefully examined and give way to choices, simplifications and assumptions so that governing inputs are identified. Eventually, a project optimization algorithm is described and evaluated against available data from existing offshore developments, focusing primarily on decreasing the overall cost of electrical transmission and on the proper choice of technology for the particular project. The impact of the proposed algorithm and its sensitivity to varying parameters, as well as its precision and reliability have been estimated and validated with encouraging results allowing for immediate implementation in the industry.  In the thesis, for confidentiality purposes, fictive though realistic scenarios are computed, results presented and commented on, conclusions drawn. Finally, implementation and analysis of results on large-scale projects also provides with better understanding of upcoming challenges inherent to new technologies on the verge to be introduced as the industry keeps growing.