Hybrid Monopile

Abstract

To meet the ambitious targets outlined in the Paris Climate Agreement of limiting global temperature rise to 1.5 degrees Celsius, global renewable power generation must triple by 2030, with offshore wind energy expected to increase exponentially to 500 GW, a fourteen-fold rise from 2020. Despite a 48% cost reduction from 2010 to 2020, offshore wind energy remains more costly per megawatt-hour than fossil fuels, highlighting the need for cost-effective innovations in offshore wind farm foundations in the North Sea. Offshore wind farms are increasingly moving into deeper waters and utilizing larger turbines, which arise challenges for traditional monopile foundations. The Hybrid Monopile (HMP) is a promising al- ternative. It integrates features from traditional monopiles and jackets, potentially enhancing structural stability, reducing environmental impact, and optimizing costs in deeper waters. This thesis evaluates the technical and economic feasibility of the HMP compared to traditional foundation types such as the traditional monopile and jacket structure, aiming to accelerate development of offshore wind energy and contribute to global climate objectives. This study uses a comprehensive methodology to assess the HMP’s structural integrity, installation feasibility, and cost-effectiveness relative to traditional monopiles and jackets. The structural analysis begins with a preliminary design phase to establish input parameters for the finite elements analysis in Abaqus. This analysis evaluates natural frequencies and stress levels under varied conditions such as water depth, soil types, and turbine sizes, assessing the HMP’s feasibility across different conditions. The installation procedures are investigated, evaluating various strategies for HMP’s and compare it with the installation strategies of traditional monopiles and jackets. The most efficient way of installation is determined for the installation of the Hybrid Monopile while considering various options. This is compared to industry standards for the installation of the traditional monopile and jacket structure. The economic evaluation involves cost modeling. This analysis provides a cost comparison based on the manufacturing and installation of the structures, highlighting the economic advantages of the HMP in deeper waters and with larger turbine. Structural assessments demonstrate that the HMP is capable of deployment in water depths up to 80 meters and supporting offshore wind turbines of up to 22 megawatts in the North Sea. Design simulations indicate the HMP’s resilience against operational stresses caused by various environmental forces. The installation strategies emphasize efficient methodologies for HMP installation. Due to the fact the hybrid monopile requires an increased number of pin piles compared to jackets, the installation cycle of the hybrid monopile is less superior to the jacket, where the traditional monopile outperforms both of them based on installation time. Economic analyses highlight that while traditional monopiles are cost-effective in waters until 40 meter, the HMP emerges as a competitive solution for deeper waters and larger turbine configurations compared to jacket structures. In conclusion, the HMP represents an advancement over traditional jackets assuming a 20% reduction in interface piece manufacturing costs. Further optimizations in the design of the Hybrid Monopile and installation procedures could enhance its competitiveness in relation with a jacket. The traditional monopile is a more cost-effective solution in environments where possible, however the HMP offers a promising solution where noise and environmental limitation arises