Marine Energy Technologies Research Articles

Harnessing Vietnam's coastal potential: Prioritizing marine energy technologies with an objectively weighting decision-making approach

Vietnam's potential to harness marine energy for sustainable development is significant due to its long coastline, yet this potential remains underutilized as current renewable energy efforts focus mainly on wind and solar power. This study addressed the challenge of selecting optimal Marine Energy Technologies (METs) for Vietnam's specific environmental and socio-economic context. A streamlined methodology, integrating the Method based on the Removal Effects of Criteria (MEREC) and the Spherical Fuzzy Combined Compromise Solution (SF CoCoSo) methods, facilitated a multi-criteria analysis that distilled expert opinions into a decision-making framework. The study identified Point Absorbers (PAB) as the most promising MET for Vietnam, with Overtopping Devices (OTD) and Salinity Gradient Power (SGP) also ranking well based on key factors like readiness and cost. This study introduces a methodology that, with a more comprehensive data set including various marine energy technologies, could provide valuable insights for decision-makers in Vietnam's marine energy sector.

Second Version of Marine Energy Technologies Online Conference [Chapter News]

Second Version of Marine Energy Technologies Online Conference [Chapter News]

A Paper on Floating Solar Power Plants: A Review

Combining marine and renewable energy technology is an eco-friendly technique to produce electricity. Solar panels are made to float on the surface of water, like in a dam or reservoir. Underwater lines deliver electricity to a transmission tower. A floating solar power plant comprises essential elements: the solar module, buoyancy system, and corrosion-resistant components. These anti-corrosion elements encompass vertical and horizontal frames, an inspection footrest, and a module mounting assembly. In addition to passing the drinking water test, the solar module should be lead-free, dust-proof, humidity-resistant, and resistant to the impacts of transient water jets. Polyethylene, used to build the buoyancy body, has a 2.5 times weight capacity. K-water's floating structure is created using magnesium alloy coating product. In comparison to ground mounted PV (GPV), FPV has a number of benefits that are addressed in this review. The influence of FSPP on water quality and aquatic life is where there is a significant study void. This review paper looks at the most recent FSPP research and analyzes its advantages, disadvantages, and prospects. In terms of different water bodies that can be employed, system effectiveness, worldwide potential, and possibility for integrating FSPP with other technologies, the evaluation sheds further light on FSPP. Key Words: Renewable energy, floating solar power Plant, floating Solar System, floating solar PV installations in the world. Conventional solar power plant (CSPP).

Improving the OWC Wave Energy Converter Power Take-Off Efficiency throughout Experimental and Numerical Characterisation of an SCIG

The increasing interest in the use of renewable energy technologies is directing attention towards the potential contribution of marine energy technologies, especially ocean wave energy, to world energy demand. While open-sea demonstrations of full-scale devices have been carried out to validate several technologies, the focus now is shifting to optimising the components for efficiency and reliability. The efficiency of the electrical generator plays a crucial role in wave-to-wire numerical models for converting wave energy into usable electricity. It provides essential data that enables the industry to reduce technical risks and uncertainties. Wave-to-wire models typically simplify the generator’s efficiency through assuming a single curve based on the load. This curve is usually provided by the machine manufacturers for the nominal rotational speed. However, the rotational speed varies in the case of air turbines used in OWC devices. Therefore, to accurately estimate decision variables derived from these models, a comprehensive efficiency map is necessary. This map should demonstrate the performance at different rotational speeds and loads, as it directly influences the estimation of key parameters. The main objective of the present work is to improve the generator behaviour of an OWC for different generator operation regimes. For this purpose, a numerical model of the generator’s efficiency will be developed throughout the segregation of losses and validated experimentally. Finally, an optimal control law will be presented to maximise the electrical power output of the wave energy converter, considering the efficiency of both the generator and the turbine.

Review of TEAMER Awards for WEC-Sim Support

Testing Expertise and Access for Marine Energy Research (TEAMER) is a U.S. Department of Energy Water Power Technologies Office sponsored program, overseen by the Pacific Ocean Energy Trust, which aims to advance the state of marine energy technologies. The program connects technology developers with experts at U.S. facilities, including numerical modeling and analysis facilities, like WEC-Sim. The WEC-Sim facility is supported by the WEC-Sim development team at Sandia National Laboratories and the National Renewable Energy Laboratory. WEC-Sim (Wave Energy Converter SIMulator) is an open-source software for simulating wave energy converters. WEC-Sim can model the multi-body dynamics of devices comprised of bodies, joints, power take-off systems, and mooring systems. Since TEAMER’s first round of support in 2020, there have been eighteen TEAMER awards focused on numerical model development in WEC-Sim. TEAMER awards for WEC-Sim support have modeled a wide range of wave energy converter archetypes, including point absorbers, attenuators, oscillating water columns, and many other novel architectures. A wide variety of studies have been conducted, leading to important insights for TEAMER partners and software improvements for WECSim. This article highlights several successful WEC-Sim TEAMER awards. The awards described herein include TEAMER recipients Ocean Motion Technologies, AquaHarmonics, iProTech, East Carolina University, Virginia Tech, Maiden Wave Energy, and the University of Massachusetts Dartmouth. The awards of these seven partners contain a wide range of investigations and cover the creation of baseline hydrodynamic models, PTO modeling, geometry optimization in both boundary element methods and WECSim, and model tuning and validation.

Public perceptions of wave energy development on the west coast of North America: Risks, benefits, and coastal attachment

While solar and wind energy continue to grow as significant sources of renewable energy, a global energy transition away from fossil fuels will require an expanding portfolio of generating resources. Marine renewable energy has the potential to contribute greatly in the coming decades, as the more predictable nature of wave energy can support the resiliency of the power grid and complement solar and inland wind generation. Yet, the broad deployment of marine energy technologies like wave energy will depend on public support, making it critical to identify the relevant factors associated with public attitudes and risk/benefit perceptions. This paper draws on social representations theory to specifically examine perceptions of wave energy on the west coast of North America, a site chosen because of the high suitability for wave energy generation and the fact that one of only three wave energy test sites in the world is under development off the coast of Oregon. Using an online survey in June 2020, we recruited a sample of 2000 respondents from California, Oregon, Washington, and British Columbia. We found a majority of respondents held positive attitudes to wave energy, but respondents also had low familiarity – with a quarter of respondents lacking sufficient information to form an opinion. We used logistic regression to identify factors correlated with wave energy attitudes, finding that respondents who were more supportive of wind and solar energy, more optimistic about new technology, and reported more familiarity with wave energy were significantly more likely to have a positive impression of wave energy. Respondents with higher levels of place attachment to coastal areas were more split, as they perceived higher benefits of wave energy – but also higher risks. Our results indicate broad appeal of wave energy on the west coast, but we caution policymakers and developers to not take initial siting processes for granted. As experience has shown for offshore wind, broad appeal does not guarantee a smooth siting process in a local context. The role of place attachment to coastal areas must be taken seriously or risk alienating local communities.

The current state on China’s marine energy industry policy

At present, China’s marine energy industry is still in its infancy, but there is no doubt that the development of this industry will help China to achieve sustainable development. Therefore, effective policies are needed to promote the industrialization of the industry as soon as possible. This paper systematically consulted the relevant information on the research and development of marine renewable energy, focusing on China’s marine energy industry policy, including the national energy strategy, the progress of China’s marine energy policy, technology policy, market policy and other related content, emphasizing the importance of marine energy policy in promoting the development of marine energy industry. Finally, in view of the deficiencies in the development of marine energy industry in China, the corresponding improvement strategies are put forward.

Characterizing the Marine Energy Test Area (META) in Wales, UK

With lack of convergence on any single wave or tidal technology, test centres have a unique role in the marine renewable energy industry. Test centres facilitate real testing at sea for devices and components at various TRLs (Technology Readiness Level), reducing the time, cost, and risks faced by marine energy developers. META (Marine Energy Test Area) is a £2.7M project managed by Marine Energy Wales (MEW), consisting of eight test areas in the Milford Haven Waterway and surrounding waters (Pembrokeshire, Wales). Although various datasets have been collected from the META test areas over the last decade, and some aspects of these data have been published in various reports, the data has not been gathered together, systematically analysed and critically assessed – the aim of this study. Here, we describe and interpret the various META datasets, including multibeam, ADCP (acoustic Doppler current profiler), and wave buoy data. We report the key parameters of relevance to testing at META, including bathymetry, the nature and magnitude of the tidal currents, turbulence, and wave climates. We make recommendations on future priorities for data collection at META, and discuss the future of the test areas, including expansion into floating wind and other evolving marine energy technologies.

Benchmarking Marine Energy Technologies Through LCA: Offshore Floating Wind Farms in the Mediterranean

Floating wind turbines are a valid option for offshore wind farms in the Mediterranean, where the sea-floor falls off rapidly with distance from the coastline. The present study concerns a Life Cycle Assessment of the environmental performance of two types of floating wind turbine. Greenhouse gas emissions of two standard models (raft-buoy and spar-buoy, 154 m rotor diameter, 6 MW installed power) were estimated in terms of Global Warming Potential (t CO2eq) with the aim of determining a benchmark for evaluating the performance of similar offshore wind farms. Thus, the aim of the paper was to create a benchmark for the design of innovative technologies, such as those developed by specialist companies, and to verify the validity of new designs and technologies in terms of avoided greenhouse gas emissions. The results show that the Carbon Intensity of Electricity of a single floating wind turbine varies in the range 26–79 g CO2eq·kWh−1, averaging 49 g CO2eq·kWh−1, in line with other studies of offshore wind turbines and other renewable energy sources (such as onshore wind and photovoltaic). Extension of our study to the whole life cycle, including manufacturing, assembly and installation, maintenance and material replacement and a hypothetical decommissioning and end-of-life, showed that wind farms are among the most promising marine renewable energy technologies for the Mediterranean.

A comparative study of laws and policies on supporting marine energy development in China and Korea

Marine energy technologies in China and Korea are still in the follow-up stage compared to advanced countries. However, both countries have abundant marine energy resources, and the research for early commercialization in development, advancement, and verification of marine energy technology is actively underway. However, for early commercialization of marine energy, national policy support, investment, and development strategies are required. In this study, the current technologies, laws, policies and incentive systems in China were compared to those in Korea, and challenges to be solved were reviewed. As a result, it was found that concrete strategies to support marine energy need to be established, and the subsidy system to induce private company participation should be improved. In addition, since recognizing the necessity of marine energy development, both countries are expected to play an important role in the global marine energy market in the future.

Power to Drive a Sustainable Ocean Economy: Assessing Potential Impacts from Emerging Marine Energy Technologies on the Un Sustainable Development Goals

Power to Drive a Sustainable Ocean Economy: Assessing Potential Impacts from Emerging Marine Energy Technologies on the Un Sustainable Development Goals

WEC Array Optimization with Multi-Resonance and Phase Control of Electrical Power Take-Off

This new research provides transformative marine energy technology to effectively power the blue economy. Harmonizing the energy capture and power from Wave Energy Converter (WEC) arrays require innovative designs for the buoy, electric machines, energy storage systems (ESS), and coordinated onshore electric power grid (EPG) integration. This paper introduces two innovative elements that are co-designed to extract the maximum power from; i) individual WEC buoys with a multi-resonance controller design and ii) synchronized with power packet network phase control through the physical placement of the WEC arrays reducing ESS requirements. MATLAB/Simulink models were created for the WEC array dynamics and control systems with Bretschneider irregular wave spectrum as inputs. The numerical simulation results show that for ideal physical WEC buoy array phasing of 60 degrees the ESS peak power and energy capacity requirements are minimized while the multi-resonant controllers optimize EPG power output for each WEC buoy.

The role of small-scale and community-based projects in future development of the marine energy sector

Despite high expectations for the sector, most marine energy technologies remain in the research and development, or at best demonstration, phase. The industry is in a period of stagnation, and requires new approaches to overcome the challenges that inhibit widespread deployment. Small-scale initiatives have proven to be a successful means of developing other renewable technologies but their role in supporting marine energy is not well researched. This paper provides a review of the barriers and opportunities presented by different policy landscapes, financial support mechanisms, markets, key actors, and wider regulatory and governance issues. Semi-structured interviews with marine energy stakeholders from the UK, Canada and Denmark were used to explore the role of small-scale marine energy projects, and were supplemented by interviews with the general public in England. This showed that while marine energy is appropriately scalable for local projects, financing remains a major hurdle. Discretionary local authority finance, as well as other novel options such as crowdfunding, tends to be relatively modest, supporting the argument for small-scale projects. A market for smaller devices exists, particularly for remote communities currently dependent on expensive energy from oil-fired generators. There remains a significant role for small-scale projects in testing the technology, contributing to reductions in cost and environmental risk. Current processes for environmental impact assessment can present a significant hurdle for small projects, but proportionate, adaptive assessments are evolving. Finally, community ownership and public participation have the potential to increase advocacy for the industry, with multi-actor partnerships presenting a positive way forward.

Resident autonomous underwater vehicles for persistent mobile ocean observing

Whether near shore or in the open ocean, stationary ocean observing systems lack the ability to respond spatially to transient and difficult-to-predict phenomena, such as mid-ocean ridge eruptions, instabilities in methane hydrate deposits, turbidite flows, sea–ice interactions, mass wasting events, or changes in coastal currents. Detecting and characterizing these types of events and the processes driving them requires mobile systems available at the time of the event onset. Ideally, mobile autonomous underwater vehicles (AUVs) would permanently be stationed in or near areas where events of interest are likely to occur. Traditionally, due to their dependence on batteries, AUV mission durations are often measured in hours and require costly on-water support vessels and human intervention, making it impractical to sustain a mobile observing presence. However, advances in cabled power/comms and renewable marine energy technologies present significant opportunities for developing persistent mobile subsea systems able to recharge their batteries from fixed underwater infrastructure. In addition to power, these “resident” AUVs will require navigation and data transmission support. Acoustic systems will play key roles as sensing systems, navigation, vehicle homing, data transfer, and advanced robotic operations. This talk will present an overview of the systems and concepts relevant to subsea mobile ocean observing systems along with example applications.

Hull geometry optimisation of wave energy converters: On the choice of the objective functions and the optimisation formulation

Wave Energy Converters (WECs) with optimised geometries and control systems have been developed in recent years to advance marine energy technologies towards commercialisation. In particular, a number of WEC hull geometry optimisation studies have been performed, due to the high cost reduction potential associated with the device structure. However, no standard and consistent method has been established for this purpose. For example, different optimisation formulations (single-objective and multi-objective), have been used, applying different optimisation algorithms. Additionally, a range of objective functions have been employed, where power maximisation has been represented through a variety of metrics, and cost minimisation expressed with diverse cost proxies. The goal of this study is to address the challenge of finding a suitable optimisation problem formulation with single-objective or multi-objective implementations, and the respective objective functions, that support the exploration of shapes that reduce the levelised cost of energy. Results show that submerged surface area cost proxies are more suitable for this purpose than volume-based cost proxies. Results from a multi-objective optimisation formulation can provide a good understanding of the solution space, whereas results from single-objective studies can be used for seeding these multi-objective optimisation approaches.

Status of Marine Current Energy Conversion in China

Marine current energy conversion (MCEC) technologies are promising renewable energy systems with some full scale and semi-commercial turbines constructed and deployed in several countries around the world. In this work, we present the status of marine current energy and systems in China and policies geared to support these. Over the past ten years the Chinese government has provided a policy framework and financial supports for the development of MCEC technologies of various design philosophies which has resulted in significant technology deployment at sea. A review of these technologies – which have turbine capacities in the range 20 kW to 650 kW, mostly tested at sea – is presented in the paper. In addition, the paper also discusses Chinese plans for marine energy test sites at sea to support prototype development and testing and concludes with a view of future prospects for the marine energy technology deployment in China.

Comparative analysis of European grid codes relevant to offshore renewable energy installations

The purpose of this paper is to highlight the most demanding aspects of grid interconnection of marine energy installations while at the same time providing an updated overview and comparative analysis of the connection requirements of eight European Grid Codes. Therefore, the major issues related to marine energy installations will be summarized as well as the requirements of this type of generation. Besides, the extent to which current Grid Codes include marine energy technologies will be analysed jointly with the need of harmonization of different Grid Codes into a generalised European grid code. Apart from this, several future trends of marine energy technology and its interconnection will be provided for the final discussion.

The potential of marine energy technologies in the UK – Evaluation from a systems perspective

Accelerated technological change plays a crucial role in enabling the low-carbon energy transition. Quantitative energy modelling exploring alternative long-term decarbonisation pathways can support policy-makers in choosing the most important areas for technology promotion. This study analyses the potential contribution of marine energy in the UK from an energy systems perspective considering the trade-offs between local lead markets and global learning, the uncertainty in the learning potential, competition with alternative technologies and impacts on system balancing. The results indicate that only under very favourable conditions, i.e. with learning rates above 15% and high global deployment, marine energy will have a significant contribution to the UK decarbonisation pathway. Alternatively, marine energy could constitute a hedging strategy against multiple failure in other low-carbon options. The early strategic investments into marine energy lead, in most cases, to a slight rise in societal welfare costs compared to the respective cases without attempts to induce marine learning and brings benefits to the electricity system. Thus, on the whole, we conclude that marine energy has the potential to contribute to the UK energy system, but there is a substantial risk that strategic investments in a national lead market will not directly pay off in the long term.

Analysis on Core Technologies and Cutting-edge Technologies of New Energy Based on Input-output Method

In this paper, taking the patent for the study and using input-output analysis method distinguish the advanced technology and the core technology in the field of new energy, which makes the number of cited patents as input, and the number of published patents as output. Patent data for this paper comes from Derwent Innovation Patents Citation Index (DII), using the Python programming language to extract the patent information in PN field and CP field for each time period and each energy sector, then matching this information in SQL database, whereby the number of one energy sector cited from another energy field. Construct the patent citations matrices to identify core technologies filed and cutting-edge technologies field by induction coefficient and influence coefficient, on this basis analyze the degree of sensitivity, to further determine which energy field makes the greater impact for the development of whole new energy field. The results show that the cutting-edge technologies field is marine energy technology research and development, the core technologies field is solar technology field, the solar technology makes the greater impact for the development of whole new energy field.

A Study of Promotion Plan for Private Corporations in Marine Energy Project

Marine Energy R&D Project of the MOF (Ministry of Oceans and Fisheries) is a representative government R&D project in the field of marine energy. The final goal of this project is ‘industrialization through commercial production of marine energy technologies led by private corporations.’ On the other hand, the lack of participation of private corporations has been identified as an obstacle. This paper suggests legal, institutional and political promotion plans to increase the participation of private corporations in the Marine Energy R&D project. In this study, 3 support systems were considered. First, the government support system for the relatively industrialized photovoltaic R&D within the renewable energy project was analyzed. Second, through an investigation of industrial development stage analysis methods, the current situation and possibilities of industrialization in the Marine Energy R&D project were studied. Based on the results, SWOT analysis was conducted to suggest legal, institutional and political supporting plans. The results of this study are expected to be used to establish an effective direction of government R&D investment and organize the legal, institutional system for a future marine energy industry in Korea.