Posters

Abstract

When planning an offshore wind farm, a unified approach between wind resource and sea state conditions is ideal, i.e., using the same wind fields used for energy yield assessment as input to wave and ocean flow models. Moreover, to assess several wind farm layouts and scenarios, a fast and accurate modelling is desired. This work presents results from fast wave and ocean flow modelling over two operating wind farms owned and operated by Ørsted: Anholt and Westermost Rough. The methodology framework presented here aims to simulate wave and ocean flow conditions in a computationally efficient way and, at the same time, achieve comparable results as traditional spectral wave and hydrodynamical modelling.  The hybrid model is called MIKE Metocean Simulator. As a first step, the Principal Component Analysis is used as a dimensionality reduction method to reduce the forcing state vector space, facilitating the required modelling selection and interpolation process. Then, the event selection extracts a subset of timesteps with representative sea states. For this purpose, the Maximum Dissimilarity Algorithm is used which can capture the most dissimilar cases and ensure the selection of the most extreme events. Hence, only the selected events are simulated with MIKE Spectral Wave and 2D Hydrodynamic models. In the last step, the modelled time series of the sea state at the output locations is a reconstruction based on statistical interpolation methods.  For wave modeling, an established methodology is already available commercially (MIKE Metocean Simulator (mikepoweredbydhi.com). For 2D  hydrodynamic (current speed, current direction and water level) modeling, a first case study with satisfactory results was presented in the WindEurope Technology Workshop 2024 in Dublin. This work brings two main innovations: combine both methodologies to simulate wave and hydrodynamic parameters for two wind farms and present results for the entire wind farm area, hence extending the point-based analysis performed in previous studies.  Results show that both Anholt and Westermost Rough have spatial gradients of wave and current speeds relevant for design. This work is part of the EU project DTWO – Digital Twin for Offshore Wind (https://dtwo-project.eu/). As a next step, we plan to consider wind farm wake effects using new mesoscale simulations generated by the project. Also, operational data of both wind farms will be made available to validate both wind, wave and ocean flow parameters.