Abstract
The Hawaiʻi Wave Surge Energy Converter (HAWSEC), a bottom-fixed oscillating surge wave energy converter, features a pitching aluminum flap connected to a hydraulic power take-off (PTO) system, generating a high-velocity jet to drive an off-the-shelf hydroelectric turbine for efficient wave-to-wire power conversion. This project, funded by the U.S. Department of Energy, focuses on de-risking technology development through advanced numerical modeling and extensive testing, aiming to achieve scalable success in wave-to-wire power conversion.
In the O.H. Hinsdale Wave Basin at Oregon State University (OSU), hydrodynamic testing of the flap structure provided vital data for the calibration of a WEC-Sim model. Similarly, a bench testing setup at the University of Hawaiʻi (UH) enabled the systematic calibration of a Simscape Fluids hydraulic PTO model. Merging these individually calibrated models into a cohesive, coupled model was a crucial step. The subsequent phase involved physical tests on this coupled system at OSU to gather a comprehensive set of validation data (see Figure). Following this, simulations that replicated the laboratory test conditions were conducted, allowing for a statistical comparison between model predictions and experimental data. The model's predictions, closely aligning with the experimental data, validated the coupling methodology’s effectiveness.
The validation of the coupling methodology represents an advancement, offering a cost-effective, scalable approach for future development. It shows that individual components, like the PTO system, can be independently designed, tested, and calibrated before their integration into a comprehensive model, lowering barriers to entry for research institutions. This modular approach encourages iterative bench testing and model calibration, substantially reducing development costs compared to testing the complete system in a wave basin or flume. Furthermore, this strategy provides a plug-and-play solution, where any new calibrated PTO design can be coupled with our fully calibrated hydrodynamic WEC-Sim model to evaluate PTO performance in a simulated environment. Should a PTO design require further validation, it can undergo physical testing in the laboratory using our physical model of the flap device, expediting the path to engineering-scale prototypes and enhancing the technology readiness level. This methodology not only encourages broader participation in wave energy research but also accelerates the discovery of highly efficient hydraulic systems, aiding in the reduction of the Levelized Cost of Energy (LCOE) and enhancing the commercial viability of wave energy conversion.
This presentation will highlight the project, with a focus on the UH bench test environment and PTO calibration. It seeks to provide attendees with a practical blueprint for exploiting the HAWSEC platform to develop innovative PTO designs, equipping them with tools and knowledge to advance hydraulic PTO technology.