International Marine Energy Journal

A framework for Analysing and Improving Graduate Attributes and Employability in the Blue Economy

2025-06-12T05:23:10+01:00

The Blue Economy plays an instrumental role in the growing offshore industry. The new and emerging sectors of Australia’s Blue Economy require an integrated understanding of technical, environmental and social aspects to support academic and industry career development which needs to be developed further at Australian universities. One of the key goals is therefore to educate a new generation of the Blue Economy workforce with detailed cross-disciplinary knowledge in future Blue Economy industries such as sustainable aquaculture industry, offshore wind and wave energy industry, green hydrogen industry and remote and autonomous technology. This work offers a first look on the potential impact of large industry – university partnerships (exemplified by the Blue Economy CRC on various disciplines and curricula.

The objective of this project is to analyse and qualify the currently implemented graduate attributes at universities and determine how to improve employability skills. This work will explore the challenges, strategies and considerations to improve educational and engagement programs for university students, researchers and practising workforce. In particular, we want to discuss pathways for collaboration between universities, industry and other partners to build a network that supports the ambitious objective of increasing employability skills for Blue Economy graduates.

Wave energy conversion using coupled balloons: A numerical investigation

2025-06-30T15:04:08+01:00

Most wave energy converters (WECs) feature rigid structures, while flexible WECs have received less attention. This study investigates a novel WEC comprising two balloons coupled through an air duct, designed as a simple and low-cost solution for harnessing wave energy. The performance of the coupled balloon wave energy converter (CBWEC) is assessed through numerical modelling, using the radiation/diffraction software HydroStar. The balloons are idealised as spheres with uniform deformation. A comprehensive parametric study evaluates the device’s performance with varying spacing, submergence, power take-off damping, and additional stiffness. Although the CBWEC was initially conceived as fully submerged, results indicate that without additional negative stiffness, its natural period is too low to resonate with ocean waves. Hence, in the absence of negative stiffness, a floating configuration offers the highest potential power, defined as the area under the power function. Hypothetically introducing negative stiffness significantly improves performance, producing five times more power than the best configuration without it. With appropriate negative stiffness, the submergence of the balloons becomes less critical. These findings will guide upcoming physical experiments to validate the proposed device. While achieving negative stiffness may be challenging in practice, the CBWEC demonstrates reasonable performance even without it, highlighting its potential as a promising WEC.

Control System Design Challenges in Renewable Energy-based Offshore DC Microgrids

2025-06-30T08:55:37+01:00

Since the majority of modern electronic devices rectify an AC input to operate via DC power, and since many distributed renewable energy sources (DRESs) inherently generate DC power, DC microgrids (MGs) are an increasingly attracting approach. DC MGs can provide a sustainable alternative for offshore facilities such as oil and gas rigs, marine shipboards, and aquaculture facilities, offering a sustainable and efficient substitute to conventional power systems. This is because these industries have access to different DRESs, especially ocean wave energy, and often utilise DC-powered modern electronic devices. When integrating different DRESs into a DC MG network for powering offshore industries, a robust control system is essential for maintaining system stability under all feasible operating conditions. This paper reviews the control system design challenges for offshore DC MGs, considering variations in generation output and in load characteristics. This review summarises the current state and technical challenges of control system design for offshore DC MGs and provides perspectives on how to address these challenges.

DC Microgrid For Emulating Offshore Energy Systems

2025-06-29T07:13:23+01:00

Offshore energy systems present unique challenges, such as remote locations and highly variable renewable power generation. The integration of hydrogen technologies—including fuel cells and electrolysers—offers a promising solution to reduce dependence on diesel generators and lower CO₂ emissions in these isolated environments. This study presents novel voltage control strategies tailored for the dynamic operation of hydrogen-based DC microgrids, specifically designed to support aquaculture applications in ocean settings. A testbed using commercial DC/DC converters and programmable sources was developed to emulate real-world marine energy conditions. The proposed droop-based control system dynamically manages fuel cell output and electrolyser input based on DC bus voltage fluctuations, ensuring stable and efficient microgrid operation. Experimental results demonstrate high tracking accuracy, with R² values of 0.9836 for solar, 0.9494 for wind, and 0.9606 for wave generation. The DC link voltage was maintained within ±5 V of the nominal 380 V under load variations, validating the robustness and responsiveness of the controller. This approach supports reliable energy management and efficient hydrogen integration, providing a scalable and cost-effective solution for sustainable offshore energy systems.

Comparing The Performance Of Different Geometries of Fixed OWC-type Wave Energy Devices Using CFD Simulations

2025-06-30T12:16:53+01:00

The Oscillating Water Column (OWC) stands out as one of the most promising wave energy converter (WEC) concepts to advance to the stage of full-scale prototype development, and a number of studies have been conducted on it. However, despite the considerable efforts of researchers and developers, this concept has not yet achieved commercial maturity, and there remains a scarcity of knowledge regarding the ideal OWC chamber geometry for efficiently harnessing wave energy. The main objective of this study is to support the development of a floating hybrid OWC – solar energy module planned for deployment within the Maldives. To meet design specifications and ensure manufacturing feasibility, we’ve opted for a hexagonal chamber geometry for the OWC device. Therefore, this paper presents the set-up, validation, and application of a two-phase incompressible 3D Computational Fluid Dynamics (CFD) model based on the Reynolds-averaged Navier-Stokes (RANS) equations and volume of fluid (VOF) surface capturing scheme approach, for a comparative study on the performance of fixed, detached from the seabed, cylindrical, rectangular, and hexagonal OWC WEC geometries. Simulations seek to evaluate the combined effect of key design parameters and wave conditions on the performance of the OWC device. The findings of this study are expected to assist in optimizing the chamber shapes to achieve maximum efficiency, while also providing significant value for the design, construction, and operation of practical OWC devices.

The The Albany M4 project: Demonstrating WA’s wave energy potential

2025-07-04T02:34:06+01:00

The paper presents elements of the design, manufacturing and deployment of a wave energy converter demonstrator in Albany, on the south coast of Western Australia (WA). The project, funded by WA Department of Primary Industries and Regional Development, the Blue Economy Cooperative Research Centre and The University of Western Australia (UWA) aims at advancing the development of the technology and at testing and validating the infrastructure and supply chain necessary for emerging ocean energy markets, including the aquaculture industry in the region.

The demonstrator is a wave attenuator called M4 for ‘Moored MultiMode Multibody’, developed by M4 Wave Power Ltd at the University of Manchester, UK. It has undergone extensive optimisation, with published results demonstrating high energy capture and excellent survivability. Design was undertaken by BE-CRC partners at BMT in collaboration with UWA. Upon operation, data associated with mooring line loads, hydrodynamic response and power generation will be made available live on a dedicated website for the benefit of the whole community.

Aspects associated with structural design, mooring design, local procurement, environmental permitting, and deployment operations are presented

Uncertainty of motion tracking system used in a floating wave energy converter model study.

2025-07-10T14:35:47+01:00

Blue Economy CRC deployed a four-float M4 (Moored Multi-Mode Multibody) device to demonstrate the potential of wave energy converters (WECs) for the Australian coast. An experimental study on a 1:15 scale model of the same device was performed in the Model Test Basin of the Australian Maritime College, investigating performance and behaviour, to aid in minimising the risks associated with open sea deployment. In model testing, the uncertainties of instruments and measurements directly affect the reliability of the results. Uncertainty analysis (UA) of WEC model studies is particularly important as it involves complex geometries, large motions and non-linear interactions. During the M4 experiment, the Qualisys motion tracking system was used to evaluate the hinge motion of the device, which is directly associated with the power capture. This paper discusses the details of an experimental investigation to precisely evaluate the uncertainties of this Qualisys motion tracking system. A calibration rig was designed to give known accurate motions to Qualisys marker arrangements, same as in the M4 model. The deviation in motion measured by Qualisys system was evaluated to better estimate the uncertainties of the system. It was noticed that there was a phase lag in other instruments with respect to Qualisys, which was unexpected. This phase lag can cause uncertainties, especially for WEC studies when measurements from different instruments are used in calculating power and this phase difference needs to be considered in the UA of the M4 model study. The conclusions from this study can be used in UA and future WEC model studies, improving the quality of the experiments.

Quantifying the Influence of Motion Damping on Co-Located Wind and Wave Energy Devices

2025-07-18T04:27:38+01:00

Offshore renewable energy holds the potential to satisfy growing demands for global, clean energy production. The co-existence of offshore wind and wave energy conversion technologies presents a compelling opportunity for sustainable energy generation at sea. This paper investigates the integration of a co-located point absorbing wave energy converter (WEC) with a monopile supported offshore wind turbine (OWT). Numerical simulations were validated with experimental data and were then used to investigate the hydrodynamic interactions of the two renewable energy systems, addressing the influence of WEC motions and damping on OWT wave loading. The full-scale geometry of the WEC and OWT were sized according to conditions at the proposed Star of the South wind farm in Gippsland, Victoria, Australia. The study found that the WEC’s heave and surge degrees of freedom are highly influential, with a 33% reduction in surge force on the OWT foundation in operational irregular sea states. Furthermore, highly energetic irregular sea states with a 100-year return period saw surge forces reduced by 19%. Although a fixed WEC operating purely as a wave mitigation device was beneficial, utilising a heave and surge coupled WEC proved to be a far more effective method for load reduction.

Assessing the lifetime O&M costs of co-located floating offshore wind and wave farms: a case study in Viana do Castelo, Portugal

2026-02-19T14:38:11+00:00

Over recent decades, offshore wind has seen a rapid growth in capacity, number of turbines, turbine size, and required area — a trend that is expected to continue to accelerate. Although less mature and still above grid-parity costs, wave energy remains a promising source of clean renewable energy. Due to its complementarity with offshore wind, co-locating offshore wind and wave energy systems into an offshore hybrid farm may not only reduce generation variability but also take advantage of shared offshore transmission systems, vessels, port infrastructure, and marine area, leveraging the vast and underutilised space between offshore wind turbines. A critical aspect to consider in the development of offshore hybrid farms is the operation and maintenance (O&M) of these assets. In this study, the O&M requirements and costs of wave-floating wind farms are assessed, considering a case study at the Portuguese test-site offshore of Viana do Castelo. Preventive and corrective maintenance plans, as well as port and vessel requirements were identified based on experience and discussions with developers. A weather window assessment based on 30-years of hindcast data was carried out to assess the impacts of weather on vessel chartering strategy and total operation costs. A sensitivity analysis to major sources of uncertainty shows the impacts of changes in the distance to port, reliability assumptions (e.g. failure rates), distribution of failure events, on total O&M costs. Results suggest that co-locating wave and floating wind farms can lead to reductions in total O&M costs due to sharing vessels and electrical assets.