Stand-alone system for Oscillating Water columns: Design and numerical simulation

Authors

DOI:

https://doi.org/10.36688/ewtec-2025-933

Keywords:

off-grid systems, Oscillating Water Column, power converter system, design and simulation

Abstract

Wave energy is an abundant renewable energy source with great potential to add to the energy mix and reduce carbon emissions. There are many wave energy devices, and the technology has a relatively low TRL compared to other renewable energy technologies. To address this issue, the sector should move towards intensive testing, not only in laboratories but focusing on testing in real-world conditions. Utility-scale projects involve large amounts of capital. A possible solution with a considerably lower investment is the use of small devices that, although not intended to supply the utility grid, can test the technology and at the same time collect important information on operation and maintenance, thereby reducing the associated risk.

The present paper focuses on the design and simulation of the power conversion and control system for a stand-alone floating oscillating water column device equipped with a biradial turbine. This work models and analyzes the design and control of the power converter system to enable effective control of the generator, maximizing the energy output under variable flow operating conditions. Simulations are conducted to evaluate the system's behaviour under different sea states, representative of the conditions predicted for the buoy deployment in the Azores, Portugal.

Author Biographies

  • Margarida Galvão, Instituto Superior Técnico, IDMEC

    Margarida Galvão holds a Bachelor of Science in Electrical and Computer Engineering and is currently pursuing a Master's degree in Energy Engineering and Management, with a specialization in Renewable Energies at the Instituto Superior Técnico, Lisbon, Portugal. During the Master's program, she focused on marine renewable energies. Several projects with strong technical, economic, environmental, and logistical aspects helped her to transfer theoretical knowledge into practice. Her master thesis deals with the design and control of the power converter system for a stand-alone Oscillating Water Column device, including numerical simulations and experimental tests. The OWC device will later be deployed in the Azores Islands, Portugal. Her background in electrical engineering and knowledge of the key details of marine renewable energy helps her to bring a different perspective to deploying off-grid WECs in the projects of the research group she is part of.

  • Pedro Costa, INESC-ID

    Pedro Costa was born in Lisbon, Portugal in 1993. He received his M.Sc (18') and Ph.D. (24') in Técnico Lisboa, University of Lisbon. He is currently a hired researcher at INESC-ID and invited assistant professor at the department of Electrical and Computer Engineering of Técnico Lisboa, University of Lisbon. His research interest focus on non-linear control and prominent applications of power electronic converters.

  • Luís M. C. Gato, Instituto Superior Técnico, IDMEC
    Luís Gato is an Associate Professor at the Department of Mechanical Engineering of Instituto Superior Técnico(IST), Universidade de Lisboa (UL), with expertise in Renewable Energy, Fluid Mechanics, and Turbomachinery. He has a PhD in Mechanical Engineering (IST, UL, 1989) and coordinates the IST Marine Renewable Energy Research Group of IDMEC/IST. Since 2012, he has been the Coordinator of the Specialisation Semester in Ocean Energy of the EUREC MSc in Renewable Energy at IST.

     His research activities focus on Wave Energy. Particular areas of interest include the computational modelling and tank testing of wave energy converters (WECs) and power take-off equipment for WECs, including air turbines. Since 2018, he has been a Member of the Steering Committee of the Implementing Agreement on Ocean Energy Systems, International Energy Agency. He has published 97 papers in international peer-reviewed journals, has a h-index factor of 37 as per Scopus, and supervised 12 completed PhD theses. He also holds nine patents in the field of wave energy.
  • Ana A. D. Carrelhas, Instituto Superior Técnico, IDMEC
    Ana A. D. Carrelhas received the M.Eng. degree in mechanical engineering with specialization in energy system from Instituto Superior Técnico, Lisbon, Portugal. Her master's thesis received an award by the renowned institution EUREC. She is currently working toward the Ph.D. degree in sustainable energy systems by MIT-Portugal. Her R&D experience comprises experimental work in laboratories and wave tanks, fieldwork (onshore and offshore) and numerical modeling.

Published

2025-09-08

Issue

Track

Grid/off-grid integration, power take-off and control

Categories

How to Cite

[1]
“Stand-alone system for Oscillating Water columns: Design and numerical simulation”, Proc. EWTEC, vol. 16, Sep. 2025, doi: 10.36688/ewtec-2025-933.