Session: Structural Modeling & Analysis II
Paper Number: 99119
99119 - A Highly Efficient and Rapid Cost-Optimization Framework for Offshore Wind Turbine Foundations for an Entire Windfarm Site
The design of monopile foundations for offshore wind turbines is a challenging and multi-disciplinary process. Detailed design of the individual positions must account for the varying geotechnical conditions and water depths at each location across the windfarm site to achieve a cost-effective design and lower the levelized cost of energy (LCOE).
The present paper presents a framework for holistic optimization of monopile foundations for a full offshore windfarm. The framework has been developed in-house at Wood Thilsted Partners and has been used for design of several full-scale wind farms including Vineyard Wind, the first commercial scale wind farm in the US. The backbone of the code is a beam finite-element based structural analysis code that performs all necessary design checks according to the governing standards. A direct coupling to various 3D FE-software packages is in place for detailed analyses of non-trivial structural details such as bolted flange connections and welded attachments. Three-dimensional FE is also used for position-specific 3D soil analysis for calibration and validation of the non-linear soil-structure interaction springs serving as boundary conditions for the model. Installation and drivability assessments are similarly included in the design flow based on the beam model and validated on-the-fly via parameterized 3D models. Everything is integrated in a fully automated optimization framework that can perform a full optimization sweep including automatic generation of design reports and drawing material ready for certification for a full windfarm of several hundred individual positions in a few hours.
Such efficiency can only be obtained by carefully tailoring the code specifically towards the specific needs of the foundation design process, thereby providing a degree of customization that cannot be performed in any commercially available software package. In contrast to common procedures where simple sensitivity studies are performed for one or a few selected positions within a windfarm, the present framework allows for exploration of a huge parameter space including thousands of unique fully optimized designs to ensure the most cost-optimal design decisions are taken for a whole windfarm. This would be impossible to do by manual procedures. The method includes tailoring the design for the capabilities of specific fabricators.
Representative examples will illustrate how selected sensitivity studies, such as diameter and clustering studies can be used for holistic cost-optimization across all positions in a windfarm.
Presenting Author: Martin Bjerre Nielsen Wood Thilsted Partners
A Highly Efficient and Rapid Cost-Optimization Framework for Offshore Wind Turbine Foundations for an Entire Windfarm Site
Paper Type
Technical Paper Publication