Marine Renewable Energy Projects Research Articles

Experimental insights on biofouling growth in marine renewable structures

Background Marine biofouling is a threat to industries working in the marine environment, representing significant costs associated with equipment impairment and loss of performance. In the Marine Renewable Energy (MRE) and other maritime sectors which operate at sea for long periods, an important aspect of biofouling is related to the type and frequency of inspections and biofouling removal procedures. Methods This study investigated important parameters of macrofouling (e.g. composition, including the presence of non-indigenous species, thickness, and weight) from communities growing on samples that emulate tubular components of marine renewable devices. The trials were performed during short periods of submersion (one to eight weeks) in the seasons when the colonisation process should be most intensive (spring, summer, and autumn). Furthermore, the frictional resistance forces generated during the scraping of biofouling from those components were investigated. Results Overall, results provide insights on the growth rates and removal requirements of biofouling in marine components. The results show that, while biofouling growth in early colonization stages might not present great detrimental effects to wave energy components, the consequent marine corrosion (fostered by biofouling) and the settlement of non-indigenous species (NIS) should be factors of concern. Conclusions Performing biofouling-related maintenance activities after the peak of maximum growth and reproduction (during the warmer seasons in temperate to cold environments) is suggested to reduce the number and frequency of activities. NIS can be detected at very early stages in the colonization process, highlighting the importance of biofouling monitoring and the implementation of biosecurity risk assessment plans early in the operational stage of MRE projects.

Assessing the impact of marine renewable energy in Portugal: an analysis based on ACO-TCN-attention

As the global demand for renewable energy continues to increase, marine renewable energy has attracted much attention as a potential source of clean energy. As a country with rich marine resources, Portugal’s marine environment is of great significance to the development of marine energy. However, the current impact assessment of marine renewable energy projects has shortcomings such as incomplete understanding of ecosystems, incomplete consideration of fishery resources and socioeconomic impacts, lack of accuracy, and failure to consider geographical differences, thus lacking comprehensiveness and accuracy. To this end, we propose the ACO-TCN-Attention model to address these shortcomings in current impact assessments of marine renewable energy projects. The goal of this model is to provide a more comprehensive, precise and nuanced analysis to better understand the impacts of these projects on ecosystems, socio-economics and local communities. “ACO-TCN-Attention” is a model architecture that combines multiple machine learning and deep learning concepts. It includes three main parts: Ant Colony Optimization (ACO), Temporal Convolutional Network (TCN) and Attention mechanism. The ant colony optimization model simulates the behavior of ants and is used to optimize the operating strategies of marine renewable energy projects. Temporal Convolutional Network specializes in processing time series data and improves the prediction accuracy of the model. The attention mechanism allows the model to dynamically focus on the pieces of information that are most important for the current task. Extensive experimental evaluation shows that our method performs well on multiple datasets, significantly outperforming other models. This research is of great significance as it provides new methods and tools for improving the environmental impact assessment of marine renewable energy projects. By understanding the potential impacts of projects more accurately, we can better balance the relationship between the development of renewable energy and environmental protection, supporting the achievement of the Sustainable Development Goals. This research also provides useful guidance and reference for future research and practice in the field of marine energy.

Empowering Communities to Participate in Marine Energy Planning and Development

To meet community priorities and equitable outcomes, marine renewable energy (MRE) projects, such as those for marine energy and offshore wind, require informed and collaborative marine spatial planning (MSP) to overcome significant cultural, societal, and economic barriers that may limit responsible and accelerated deployment. Effective MSP brings together coastal communities and ocean users to coordinate decision-making for sustainable use of marine resources. The goal of this project is to develop digital tools to enable easy access to information, interactive visualization tools, and feedback mechanisms to empower communities to engage in meaningful communications with other stakeholders in the MSP process.
 In collaboration with community organization partners, the Santa Barbara Maritime Museum and Redwood Community Action Agency, we held community-based workshops to solicit needs for communities to gain knowledge and communicate concerns about MRE development. The key results from initial outreach activities are:
 
 The MRE planning process must incorporate stakeholder feedback starting in its early stages (as early as siting). Community benefits must be clearly articulated and quantified.
 Communities generally distrust offshore energy developers. Communication with regulators and developers together would be useful.
 Community members are eager to learn about MRE. Their biggest knowledge gaps are MRE device and array characteristics (size, extent, location) and effects of MRE development on the viewshed, recreational activities, and on wildlife.
 There is too much information available over disparate sources. Community members do not know where or how to search for answers to questions about MRE development in their communities (or elsewhere).
 Community members want to hit the ‘Easy Button’. Data need to be digestible and tools need to be easy to use with little technical knowledge or experience necessary.
 
 Outreach activities guided the development of the following digital tools:
 
 Interactive infographics to communicate topics of concern (e.g., viewshed impacts and potential interactions with whales) in a visually engaging and interative platform.
 News feed relevant to MRE to quickly digest headlines and read articles in greater detail, sort articles by topic, and react to articles or other comments.
 Artificial intelligence (AI) driven chat bot, which uses the latest in AI, namely GPT-3 (Generative Pre-trained Transformer 3), to produce real-time answers to user questions. Answers are logged, and can be reviewed and revised by marine energy experts to provide human vetting of the results.
 Commenting system to provide feedback on information throughout the site, as well as the tools themselves.
 
 These tools will empower communities with information and feedback mechanisms to promote meaningful stakeholder engagement and communications, and therefore, informed decision-making. These tools represent a major leap forward in ocean multi-use management with MRE.

Automated detection of wildlife in proximity to marine renewable energy infrastructure using machine learning of underwater imagery

Environmental interactions of marine renewable energy (MRE) projects are challenging to monitor, and key questions remain about their potential impacts. Processing large volumes of environmental data acquired from submarine monitoring and the use of machine learning to identify presence and interactions of marine wildlife with MRE infrastructure are powerful tools for assessing the environmental response to MRE infrastructure. The use of automated image analysis for species identification and enumeration using algorithms like convolutional neural networks can vastly reduce the time required to extract usable data from submarine imagery compared to manual expert processing. We present a novel industry-ready image processing workflow for automated wildlife detection developed using 1000+ hours of underwater video footage obtained by Nova Innovation Ltd. from their operational tidal stream turbine array at Bluemull Sound in Shetland, Scotland. The objective of this work was to develop a workflow and associated algorithms to automatically filter many hours of underwater video, remove unwanted footage, and extract only video containing marine mammals, diving birds or fish. The workflow includes object detection through advanced image analysis, image classification using machine learning, statistical analyses such as quantification of data storage reduction and number of detections, and automated production of a summary report. Blind tests were undertaken on a subset of videos to quantify and iteratively improve the accuracy of the results. The final iteration of the workflow delivered an accuracy of 80% for the identification of marine mammals, diving birds and fish when a three-category (wildlife, algae, and background) classification system was used. The accuracy rose to 95% when a two-category system was used, and objects were classified simply as ‘target’ or ‘non-target’. The entire workflow can be run from video inception to production of an automated results report in approximately 30 minutes, dependent on size of input data, when environmental conditions such as water clarity and key species of interest are familiar to the algorithm. The accuracy and runtime speed of the workflow can be improved through expanding the training dataset of images used in the development of this initial tool by including additional species and water conditions. Application of this workflow significantly reduces manual processing and interpretation time, which can be a significant burden on project developers. Automated processing provides a subset for more focused manual scrutiny and analysis, while reducing the overall size of dataset requiring storage. Auto-reporting can be used to provide outputs for marine regulators to meet monitoring reporting conditions of project licences. Integration of this workflow with automated passive acoustic monitoring systems can provide a holistic environmental monitoring approach using both underwater imagery and acoustics.

Use of multibeam imaging sonar for observation of marine mammals and fish on a marine renewable energy site.

Environmental data is crucial for planning, permitting, execution and post construction monitoring of marine renewable energy projects. In harsh conditions in which marine renewable energy is harvested, integrated monitoring platforms comprising multibeam imaging sonar systems coupled with other sensors can provide multiparametric data of the marine environment surrounding marine renewable energy installations. The aim of this study was to test the possibilities of observing the occurrence of fish and marine mammals using a multibeam imaging sonar system deployed at a wave power test site. The results obtained from a ten-day data set proved the platform as suitable for long time underwater monitoring and also revealed that the occurrence of fish and marine mammals was distributed across characteristic time and space domains. Large fish [>0.4 m] frequently occurred at night-time and near the benthic zone. Small fish [<0.2 m] frequently occurred during daylight and within the pelagic zone. The occurrence of seals was periodically distributed along a daily cycle, with intervals of 1-2 hours between maxima and minima. In conclusion, the use of multibeam imaging sonar can be a reliable technique for the qualitative and quantitative observations of fish and marine mammals in general and at marine renewable energy sites specifically, including protected and economically important species.

Evaluation of the adverse weather conditions associated to some significant European marine renewable energy projects

The aim of the present work is to provide a general picture of the adverse weather conditions corresponding to the sites from the European coastal environment where various offshore projects are developed. In the first part of the work, the ERA5 wind and wave data (24 values per day) are processed in order to obtain the time series that cover the 10-year time interval from January 2011 to December 2020. By using some particular criteria that define the operability limit of several installation equipment (as for example the floating barges) it was possible to define several case studies. From the preliminary analysis of the wind conditions (at 10 m height above the sea level) it was noticed that the sites located in the northern regions (ocean environment) indicate higher values of the wind speeds, that can go up to 8.3 m/s compared to the value of 6 m/s indicated for the Gloria drilling platform in the Black Sea. As expected, the adverse weather patterns are directly related to the local marine conditions, being required restrictions higher than 80% in the case of the operations that are limited by the occurrences of the waves with significant wave heights higher than 1.25 m, compared to only 3.3% that define the north-western part of the Mediterranean Sea (Mistral project). The number of available windows requiring a much longer time interval (ex: 96 h) is higher in the case of Mistral and Gloria sites, being counted at least 48 opportunity events for the waves with significant wave heights below 0.5 m. Finally, it is important to mention that the analysis of the adverse weather conditions represents an important element for the marine renewable energy sector, especially as regards the enclosed basins, such as the Mediterranean or the Black seas, where offshore wind projects are expected to be implemented.

Early biofouling colonization stages: Implications for operation and maintenance planning in marine renewable energy projects

Background: Marine biofouling is a threat to industries working in the marine environment, representing enormous costs associated with equipment impairment and loss of performance. In the Marine Renewable Energy (MRE) and other maritime sectors which operate at sea for long periods, an important aspect of biofouling is related to the type and frequency of maintenance. Methods: This study investigated important parameters of macrofouling (for example composition, including the presence of non-indigenous species, thickness, and weight) from communities growing on small-scale wave energy components in marine conditions. The trials were performed during short periods of submersion (one to eight weeks) in the seasons when the colonisation process should be most intensive (spring, summer, and autumn). Furthermore, the frictional resistance forces generated to scrape the biofouling from those artificial components were investigated. Results: Overall, results show that while biofouling growth in early colonization stages might not present great detrimental effects to wave energy components, although marine corrosion and the settlement of non-indigenous species (NIS) should be factors of concern. Conclusions: It is suggested to perform biofouling-related maintenance activities after the peak of maximum growth and reproduction (during the warmer seasons in temperate to cold environments) to reduce the number and frequency of activities. NIS can be detected very early in the colonization process, highlighting the importance of biofouling monitoring and the implementation of biosecurity risk assessment plans early in the operational stage of MRE projects.

Practical Approaches for Providing Empirical Data on Seabird Behavior and Prey Assemblages in Tidal Channels

Persisting knowledge gaps relating to the ecological context and potential environmental impacts of marine renewable energy (MRE) devices continue to add substantial costs and uncertainty to MRE projects globally. Increasingly sophisticated technological approaches to environmental monitoring can have fundamental non-trivial shortcomings for environmental impact assessment (EIA), whilst substantial practical and financial costs of deployments can prevent their application. For the tidal stream energy (TSE) sector, there is a need for practical and cost-effective methods that can provide site-specific information on predator behavior and associated prey assemblages. Considering existing knowledge of animal communities in tidal channel environments, a proportional approach using shore-based observation and baited fish trap methods was developed. During April 2021, a trial of these methods was conducted in tidal channel environments in Shetland, UK. The practical application of the proposed approach is demonstrated here with results from three tidal channels including Bluemull Sound, the site of active TSE installations (the Shetland Tidal Array). Observation of predator behavior across the study sites are reported for great cormorant Phalacrocorax carbo and European shag Phalacrocorax aristotelis. Seabird diving data calculated from the shore-based observations provided metrics relevant to informing EIA and collision risk modelling including dive duration, dives per minute, and % time underwater. Fish trap deployments targeted the benthic and demersal prey of these predators in the three study sites and across a range of depths and hydrodynamic conditions. A variety of fish and invertebrate species known to be important components of benthic-foraging seabird diet were successfully captured by the traps, providing basic biological information on the prey assemblages observed in each site. The fish species observed in the highest abundance were saithe Pollachius virens and cod Gadus morhua. Benefits, limitations, and applications of this approach are discussed along with various factors relating to the performance of both methods. The shore-based observations rapidly identified relevant patterns in predator foraging activity which informed the targeted deployment of fish traps to provide complementary prey data. This novel combined approach has potential to reduce costs and uncertainty in EIA and for supporting the responsible development of the MRE industry.

What Participation Means in Marine Spatial Planning Systems? Lessons from the French Case

ABSTRACT There is already a substantial body of literature examining the participation issues in Marine Spatial Planning (MSP). This paper addresses these issues in the French MSP process. Using qualitative materials, it examines the participation process from four perspectives: structural, contextual, organisational, methodological. It shows that public participation in the French MSP system is still mostly procedural. Also, in most other EU countries, participation is used as a tool for resolving conflicts about use of the sea as well as to build acceptability for marine renewable energy projects. Whatever the role participation plays, it requires a critical attention in MSP processes.

A Decision Support Tool for Long-Term Planning of Marine Operations in Ocean Energy Projects

Ocean energy is a relevant source of clean renewable energy, and as it is still facing challenges related to its above grid-parity costs, tariffs intended to support in a structured and coherent way are of great relevance and potential impact. The logistics and marine operations required for installing and maintaining these systems are major cost drivers of marine renewable energy projects. Planning the logistics of marine energy projects is a highly complex and intertwined process, and to date, limited advances have been made in the development of decision support tools suitable for ocean energy farm design. The present paper describes the methodology of a novel, opensource, logistic and marine operation planning tool, integrated within DTOceanPlus suite of design tools, and responsible for producing logistic solutions comprised of optimal selections of vessels, port terminals, equipment, as well as operation plans, for ocean energy projects. Infrastructure selection logistic functions were developed to select vessels, ports, and equipment for specific projects. A statistical weather window model was developed to estimate operation delays due to weather. A vessel charter rate modeling approach, based on an in-house vessel database and industry experience, is described in detail. The overall operation assumptions and underlying operating principles of the statistical weather window model, maritime infrastructure selection algorithms, and cost modeling strategies are presented. Tests performed for a case study based a theoretical floating wave energy converter produced results in good agreement with reality.

Goal programming models with interval coefficients for the sustainable selection of marine renewable energy projects in the UK

In this paper, a strategic decision making model for the sustainable development of marine renewable energy is proposed, and a specific application to the United Kingdom (UK) is demonstrated. As an island nation the UK benefits from significant marine energy potential which is providing an increasing contribution to UK's renewable energy portfolio. The paper investigates the question of how decision makers can be aided to reach a decision on which types of marine renewable energy projects should be chosen for development given that strategic energy planning is subject to a number of uncertain parameters and multiple sustainability objectives. In this context, the contribution of this paper lies in the combination of renewable energy portfolio selection and the application of multi-objective methods. Interval coefficient goal programming models are adopted in order to address the impreciseness and uncertainty associated with the goals and coefficients of the models in the context of renewable energy selection. The potential renewable energy projects are clustered in order to aid the decision making process and preferential weight sensitivity methods are employed. Conclusions are drawn for optimistic and pessimistic scenarios in the context of UK marine renewable energy planning.

Wave energy flux variability and trend along the United Arab Emirates coastline based on a 40-year hindcast

Abstract Wave climate and associated energy characterization is essential for an assessment of a country’s renewable energy potential. A wave model was validated against satellite data with good performance in terms of error metrics. The hindcast data, covering the period 1979–2018, was used to describe the spatial, seasonal and interannual variability and trend of wave energy flux along the United Arab Emirates coastline. The annual mean wave energy flux along the study area is higher at the central region reducing towards the south and north. The wave energy shows a clear seasonality and interannual variability for all locations with higher and lower energy during winter and autumn, respectively. A trend analysis of the historical data indicates an increase in annual mean energy flux along the coast. Alongshore, seasonal and interannual variability of wave energy flux and direction should be considered in the initial stages of marine renewable energy projects. A detailed analysis of historical wave energy trends and influence of large-scale climate indices will be particularly relevant for longer-term projects.

Enhancing local support for tidal energy projects in developing countries: Case study inFlores Timur Regency, Indonesia

AbstractTidal energy is a new renewable energy source that can be used to provide electricity to remote islands, while contributing to climate change mitigation. Like all renewable energy projects, public awareness and support are not only crucial for the successful development of marine renewable energy projects too, but also aid the private sector project developers in making long‐term plans. As information about tidal energy is not easily available, public views toward it are not well known, making it challenging for the project developers to strategize implementation strategies. Moreover, the limited studies focusing on such social aspects of tidal energy come from advanced countries, highlighting the lack of focus on cases from developing countries. Our study fulfills this gap by providing a case study focusing on the social aspects of tidal energy in a developing country, which can be utilized by developers for designing their public engagement strategies. We estimate the public support for tidal energy in eastern Indonesia using two methods: (a) stages of development and (b) information provision. Using the first method, we found that support for tidal energy is lower in the initial stages, but it keeps rising once the public can realize the benefits. The second method shows that though people tend to support tidal energy, the role of information provision is dissimilar compared with western cases. Additionally, Probit modeling shows thatAge,Education,Collective Outcome Favorability, and especially,Individual Outcome Favorabilityare the key factors that positively impact the support for tidal energy in eastern Indonesia.

A review of reliability analysis of offshore scour protections

The R&amp;D project Oracle – offshore risk analysis for climate change adaptation and lifetime extension – is focused on optimising the design of scour protection schemes for the extended lifetime of offshore foundations. This project proposes an optimisation of scour protections by combining reliability-based techniques with the novel concepts of dynamic and wide-graded armour layers. The ultimate goal is to develop a decision support system (DSS) for scour protection design and risk and reliability analysis to be used by professionals and researchers dealing with fixed foundations applied to marine renewable energy projects (e.g. wind, wave and tidal). However, a meaningful implementation of such a DSS implies prior analysis of several knowledge gaps related to scour protection in the offshore environment, which are yet to be fully addressed in the literature. This paper provides a brief review of the scientific and technical challenges in the research field of reliability of offshore scour protection. On the basis of identified challenges, the discussion of future research lines is performed with a particular focus on the aim of the Oracle project. The recent findings related to risk and reliability analysis of offshore scour protection are addressed and framed within the existing knowledge gaps in the literature.

Evaluation of Co-Existence Options of Marine Renewable Energy Projects in Japan

Consensus building among local stakeholders is vital for the success of the proposed initial commercial marine renewable energy (MRE) projects in Japan. Even though the literature on stakeholder acceptance highlights the importance of creating local benefits and co-creation options, very few studies and almost no empirical data have been published on the application of non-monetary benefit creation schemes in the context of MRE. Hence, the purpose of this study was to systematically evaluate the possible co-existence options available for Japan’s MRE projects through data collected from interviews and questionnaire surveys in two development sites in Nagasaki and Kitakyushu in Southern Japan. To overcome the limitations of data unavailability and uncertainty, the Dempster Shafer Analytic Hierarchy Process (DS-AHP) was used for evaluating the best co-existence strategy out of five potential options. The results indicate that local fisheries prefer the oceanographic information sharing option whereas most of the other stakeholders prefer using local resources to construct and operate the power plant, creating business involvement opportunities for the local community. Analysis of stakeholders’ decision behaviors suggests that perceived impacts, knowledge, and values influence the preference decision. In addition to the validation of stakeholder preference of the previously proposed co-existence options with empirical data, this study provides a robust method to further evaluate the potential options with the availability of new data.

Governance challenges of marine renewable energy developments in the U.S. – Creating the enabling conditions for successful project development

Increasingly, marine renewable energy developments are viewed as an opportunity to meet climate change obligations, with the added benefit of powering the economy and the creation of jobs. Technical, economic and engineering challenges co-exist with governance challenges in the development of large-scale marine renewable energy projects. This paper addresses the question, if the prerequisites for sustainable project development are evident in selected case studies. It also asks what lessons can be learned from current practice in the context of energy governance at the local level. The authors argue that these lessons can be central enablers to support decision makers in future programmes, to better understand how to build the enabling conditions for programme implementation towards renewable energy at higher spatial scales of governance, importantly the national level. The study builds on a multiple stakeholder approach involving interviews and group discussions with key individuals from industry, government and civil society in emerging pilot programmes along the East Coast of the United States (U.S.). New policy windows were opening at the time of the analysis and ambitious development was underway by a range of actors who are driving progress in the sector and positioning the area to become a major provider of blue energy.

Marine Renewable Energy in the Mediterranean Sea: Status and Perspectives

In this work, an extended overview of the marine renewable energy in the Mediterranean Sea is provided as regards current status, potential problems, challenges, and perspectives of development. An integrated and holistic approach is necessary for the economic viability and sustainability of marine renewable energy projects; this approach comprises three different frameworks, not always aligned, i.e., geotechnical/engineering, socio-economic, and environmental/ecological frameworks. In this context, the geomorphological, climatological, socio-economic, and environmental/ecological particularities of the Mediterranean basin are discussed, as they constitute key issues of the spatial context in which marine renewable energy projects are to be implemented. General guidelines for the sustainable development of marine renewable energy in the Mediterranean are also provided.

Hydrodynamic Impacts of a Marine Renewable Energy Installation on the Benthic Boundary Layer in a Tidal Channel

Field measurements of the flow in the benthic boundary layer (BBL) of a tidal channel are presented which compare data collected in the wake of a marine renewable energy installation (MREI) with control data representative of the natural conditions. The results show significant flow modification in the wake of the MREI including a reduction in mean velocity, enhanced turbulence, and the breakdown of the natural structure and dynamics of the BBL. This study provides new information relevant to the environmental impact assessment of MREIs and to the design and consenting of marine renewable energy projects.

Observations and tracking of killer whales (Orcinus orca) with shore‐based X‐band marine radar at a marine energy test site

AbstractThe Atlantic killer whale (Orcinus orca) is a top‐level marine predator with a global range, being found in all of Earth's oceans. The potential interaction between killer whales and marine renewable energy projects requires surveillance and monitoring efforts that call for new technologies, with marine radar showing promise in the field. Marine radar images recorded at the European Marine Energy Centre (EMEC) were used to track a pair of male killer whales undertaking Surface Active Behavior (SAB) with visual observations used as validation. Using a tidal prediction model, the tide‐adjusted, radar‐derived target speeds between SAB events provide estimates of swim speeds averaging 4 m/s and time between SAB events of 30 s. The similarities between the radar signatures of the animals and sea clutter, combined with their low occurrence compared to other imaged phenomena renders automatic detection with this system difficult. However, the combination of opportunistic radar imagery and independent visual observation has allowed the radar signature of one form of killer whale SAB to be documented. It is hoped that with a greater number of validated observations such as these that automated, radar‐based identification and the benefits it will bring to long‐term observations at MRE sites will be possible.

Moving from consultation to participation: A case study of the involvement of fishermen in decisions relating to marine renewable energy projects on the island of Ireland

The development of the marine renewable energy (MRE) will impact traditional users of the marine resource, such as commercial fishermen. This could potentially lead to opposition and spatial conflict. The successful development of the MRE sector will heavily depend on the acceptance of projects by fishing communities. Effective stakeholder engagement is crucial to enhancing acceptance among fishermen. The consultation process is one of the key ways in which to engage fishermen and enable them to participate in decision-making. There is agreement among experts in the field that despite its importance, the consultation process is not effective and it is often carried out from the top down with little opportunity for real participation. A mixed methods research approach was used to examine the experiences of fishermen on their level of involvement in consultations and decision-making on marine renewable energy projects. In total, 104 surveys and 14 in-depth interviews were carried out with fishermen operating from ports at three case study sites around the island of Ireland where MRE projects were being developed. Just over half (56%) of those surveyed felt that they had been involved in consultations, while only 22% felt that they had been involved in decisions made on the projects. The use of participatory mapping tools in the selection of sites for MRE development provides an opportunity for fishermen to influence decisions. Designing and implementing marine spatial plans could also help to provide clarity and transparency over how trade-offs in the use of sea space are dealt with.