A supply chain model for the BLUE-STAR Tension Leg Platform

Abstract

The offshore wind market is developing fast due to climate change. To ful fil in the growing demand for offshore wind market, one has to look for floating offshore wind solutions as nearshore shallow waters are depleting. Several types of floating wind structures can be distinguished in the following categories; Spar, semi-submersible and Tension Leg Platform (TLP) structures. Blue water developed a floating wind TLP, the BLUE-STAR, which is still under development and has not yet been applied in offshore wind projects.At the moment there are many factors unknown about the concept. This in comparison to semi-submersible structures of which more knowledge is available. The aim of the thesis is to describe if the TLP concept has an advantage over the semi-submersible structure and if the newly developed TLP concept can be a viable solution. For this, a simulation model to simulate the logistics of both structures, is developed. First, different types of offshore wind turbines are classified, including TLP and semi-submersible structures. This is followed by challenges the logistics of offshore wind farms are currently confronted with. This points out that the most important challenges are due to substructures, environmental conditions and T&I. Next, the logistic process of both the TLP and SSB structure are described. This is followed by a literature study which is divided into literature on weather conditions and literature on operations and logistics, in which the analytical approach and simulation-based methods are described.Discrete Event Simulation is used for the simulation model in Matlab. This is followed by an extensive description of the logistic process in general. The second part of the chapter elaborates on implementation of both structures into the described model. The fourth part of this thesis, elaborates on implementation of the simulation model by explaining the decisions and assumptions made for the simulation model. Furthermore, this part also discusses the inputs of the logistic process simulation.  The weather data provided by Blue water for the use of the simulation model is presented and this part of the thesis gives an evaluation of the simulation model. Based on this evaluation, is it concluded the simulation model functions correctly. In the final part of this thesis, the results of the logistic simulations of both structures are compared and a  sensitivity analysis is performed. For the sensitivity analysis, 4 cases are studied, these are: varying wind speed and wave height, variation of transport duration, seasonality and varying team performance. The aim of this sensitivity analysis is to study the influences of different input conditions.  Finally, results of the simulations and performed sensitivity analysis indicate that the newly developed TLP concept is not a realistic alternative compared to the SSB structure.