Session: 09-05-04 Wave Energy: Power Take Off Systems

Submission Number: 175399

Integrated Single Mooring Line and Power Take-Off for Point Absorber Wave Energy Converters 

Point absorber wave energy converters (WECs) are recognized as a potential solution for sustainable ocean energy extraction due to their ability to efficiently harness point-source oscillations. A critical aspect affecting WEC survivability, power capture, and overall system economics is the design and integration of both the mooring and the power take-off (PTO) systems. While multi-line mooring configurations have been widely studied, there is a lack of systematic investigation into the feasibility and operational behavior of single mooring line systems, particularly those that integrate the mooring line as an element of the PTO drivetrain. This study aims to evaluate the benefits of the integration of PTO with single mooring line compared to conventional multi-line configurations under various environmental conditions. The research utilizes time-domain dynamic simulations in OrcaFlex with detailed parameterization of mooring system characteristics, such as line length, anchor radius, and clump weight positioning. Validations are conducted against 1:10 scale wave tank experiments using a 1.5-meter diameter model WEC at 3-meter water depth, which corresponds to full-scale scenarios of a 15-meter diameter WEC in 30-meter water depth. We systematically assess mooring line tensions, power output efficiency, horizontal excursion of the WEC, and total system costs to determine whether the PTO-integrated single mooring line can withstand harsh marine environments and offer advantages in terms of reduced system complexity and lower installation costs. The outcomes are expected to provide actionable guidance for the next generation of WEC engineering and deployment. Future work will focus on advanced PTO control strategies and in-depth analysis of dynamic interactions between the PTO and mooring systems to further enhance performance and reliability.

Presenting Author: Wei-Ying Wong University of Michigan, Naval Architecture and Marine Engineering

Presenting Author Biography: Wei-Ying Wong is a Ph.D. Candidate in Naval Architecture and Marine Engineering at the University of Michigan. Her research focuses on offshore renewable energy systems, with particular emphasis on mooring and subsea cable dynamics. Her current work combines numerical modeling and experimental validation to investigate dynamic subsea cable vibration and mooring loads through projects funded by the U.S. Department of Energy and the National Offshore Wind Research & Development Consortium. Before her doctoral studies, she worked in Taiwan on floating offshore wind development and foundation engineering.

Authors:

Jui-Chen Chen Department of Naval Architecture and Marine Engineering, University of Michigan - Ann Arbor
Wei-Ying Wong University of Michigan, Naval Architecture and Marine Engineering
Wen-Yang Hsu Department of Harbor and River Engineering, National Taiwan Ocean University
Lei Zuo Department of Naval Architecture and Marine Engineering, University of Michigan - Ann Arbor