Marine Renewable Energy Sector Research Articles

Creating New Antifoulants Using the Tools and Tactics of Medicinal Chemistry.

ConspectusThe unwanted accumulation of marine micro- and macroorganisms such as algae and barnacles on submerged man-made structures and vessel hulls is a major challenge for any marine operation. Known as biofouling, this problem leads to reduced hydrodynamic efficiency, significantly increased fuel usage, microbially induced corrosion, and, if not managed appropriately, eventual loss of both performance and structural integrity. Ship hull biofouling in the international maritime transport network conservatively accounts for 0.6% of global carbon emissions, highlighting the global scale and the importance of this problem. Improved antifouling strategies to limit surface colonization are paramount for essential activities such as shipping, aquaculture, desalination, and the marine renewable energy sector, representing both a multibillion dollar cost and a substantial practical challenge. From an ecological perspective, biofouling is a primary contributor to the global spread of invasive marine species, which has extensive implications for the marine environment.Historically, heavy metal-based toxic biocides have been used to control biofouling. However, their unwanted collateral ecological damage on nontarget species and bioaccumulation has led to recent global bans. With expanding human activities within aquaculture and offshore energy, it is both urgent and apparent that environmentally friendly surface protection remains key for maintaining the function of both moving and stationary marine structures. Biofouling communities are typically a highly complex network of both micro- and macroorganisms, representing a broad section of life from bacteria to macrophytes and animals. Given this diversity, it is unrealistic to expect that a single antifouling "silver bullet" will prevent colonization with the exception of generally toxic biocides. For that reason, modern and future antifouling solutions are anticipated to rely on novel coating technologies and "combination therapies" where mixtures of narrow-spectrum bioactive components are used to provide coverage across fouling species. In contrast to the existing cohort of outdated, toxic antifouling strategies, such as copper- and tributyltin-releasing paints, modern drug discovery techniques are increasingly being employed for the rational design of effective yet safe alternatives. The challenge for a medicinal chemistry approach is to effectively account for the large taxonomic diversity among fouling organisms combined with a lack of well-defined conserved molecular targets within most taxa.The current Account summarizes our work employing the tools of modern medicinal chemistry to discover, modify, and develop optimized and scalable antifouling solutions based on naturally occurring antifouling and repelling compounds from both marine and terrestrial sources. Inspiration for rational design comes from targeted studies on allelopathic natural products, natural repelling peptides, and secondary metabolites from sessile marine organisms with clean exteriors, which has yielded several efficient and promising antifouling leads.

Techno-Economic Feasibility of the Use of Floating Solar PV Systems in Oil Platforms

Offshore facilities have high energy demands commonly accomplished with local combustion-based power generators. With the increased commercialization of the marine renewable energy sector, there is still a need for research on floating photovoltaic installations on their performance and economic perspective. This paper investigates the techno-commercial feasibility of installing a battery-integrated floating solar photovoltaic (FPV) system for an offshore oil platform facility in Abu Dhabi. The performance analysis of two floating PV design schemes has been evaluated using the PVsyst design tool. The proposed system’s annual solar energy availability from the PVsyst 7.2.21 output was validated with MATLAB Simulink R2022b with a deviation of 1.85%. The optimized solution achieved the Levelized Cost of Electricity (LCOE) of 261 USD/MWh with a Discounted Payback Period of 9.5 years. Also, the designed system could reduce carbon emissions by 731 tons per year. Furthermore, it was recognized that the contribution of the marine sector to the construction of floating platforms influences the success of floating PV systems. Independently authorized floating PV system designs would guarantee insurability from the viewpoints of investors and end users.

A Review of Unmanned Aerial Vehicles Usage as an Environmental Survey Tool within Tidal Stream Environments

Tidal energy is a rapidly developing area of the marine renewable energy sector that requires converters to be placed within areas of fast current speeds to be commercially viable. Tidal environments are also utilised by marine fauna (marine mammals, seabirds and fish) for foraging purposes, with usage patterns observed at fine spatiotemporal scales (seconds and metres). An overlap between tidal developments and fauna creates uncertainty regarding the environmental impact of converters. Due to the limited number of tidal energy converters in operation, there is inadequate knowledge of marine megafaunal usage of tidal stream environments, especially the collection of fine-scale empirical evidence required to inform on and predict potential environmental effects. This review details the suitability of using multirotor unmanned aerial vehicles within tidal stream environments as a tool for capturing fine-scale biophysical interactions. This includes presenting the advantages and disadvantages of use, highlighting complementary image processing and automation techniques, and showcasing the limited current examples of usage within tidal stream environments. These considerations help to demonstrate the appropriateness of unmanned aerial vehicles, alongside applicable image processing, for use as a survey tool to further quantify the potential environmental impacts of marine renewable energy developments.

Marine energy digitalization digital twin's approaches

Digital twins (DTs) promise innovation for the marine renewable energy sector using modern technological advances and the existing maritime knowledge frameworks. The DT is a digital equivalent of a real object that reflects and predicts its behaviours and states in a virtual space over its lifetime. DTs collect data from multiple sources in pilots and leverage newly introduced low-cost sensor systems. They synchronize, homogenize, and transmit the data to a central hub and integrate it with predictive and learning models to optimize plant performance and operations. This research presents critical aspects of DT implementation challenges in marine energy digitalization DT approaches that use and combine data systems. Firstly, the DT and the existing framework for marine knowledge provided by systems are presented, and the DT's main development steps are discussed. Secondly, the DT implementing main stages, measurement systems, data harmonization and preprocessing, modelling, comprehensive data analysis, and learning and optimization tools, are identified. Finally, the ILIAD (Integrated Digital Framework for Comprehensive Maritime Data and Information Services) project has been reviewed as a best EU funding practice to understand better how marine energy digitalization DT's approaches are being used, designed, developed, and launched.

‘Scaling up’ our understanding of environmental effects of marine renewable energy development from single devices to large-scale commercial arrays

Global expansion of marine renewable energy (MRE) technologies is needed to help address the impacts of climate change, to ensure a sustainable transition from carbon-based energy sources, and to meet national energy security needs using locally-generated electricity. However, the MRE sector has yet to realize its full potential due to the limited scale of device deployments (i.e., single devices or small demonstration-scale arrays), and is hampered by various factors including uncertainty about environmental effects and how the magnitude of these effects scale with an increasing number of devices. This paper seeks to expand our understanding of the environmental effects of MRE arrays using existing frameworks and through the adaptation and application of cumulative environmental effects terminology to key stressor-receptor interactions. This approach facilitates the development of generalized concepts for the scaling of environmental effects for key stressor-receptor interactions, identifying high priority risks and revealing knowledge gaps that require investigation to aid expansion of the MRE sector. Results suggest that effects of collision risk for an array may be additive, antagonistic, or synergistic, but are likely dependent on array location and configuration. Effects of underwater noise are likely additive as additional devices are deployed in an array, while the effects of electromagnetic fields may be dominant, additive, or antagonistic. Changes to benthic habitats are likely additive, but may be dependent on array configuration and could be antagonistic or synergistic at the ecosystem scale. Effects of displacement, entanglement, and changes to oceanographic systems for arrays are less certain because little information is available about effects at the current scale of MRE development.

Assessing the effect of onshore and offshore Wave Energy Converters on seafloor integrity combining image-based and acoustic methods

The European Atlantic Ocean offers great opportunities for the development of projects for renewable energy extraction, and the Marine Renewable Energy sector is developing different technologies for energy converters, including Wave Energy Converters. Besides, the European Commission is adopting measures and politics to increase the installed capacity of ocean energy. However, there are still uncertainties on the potential environmental effects of wave energy converters, which led regulators and stakeholders to perceive their operation as a risky activity. To overcome the non-technological barriers that could hinder the development of marine renewable energies, and improve the knowledge on the impacts on the seafloor integrity (among others), SafeWAVE project set an Environmental Research Demonstration Strategy based on the collection, processing, modelling, analysis and sharing of environmental data collected in Aguçadoura (Portugal), Armintza (Spain) and Le Croisic (France) representing different types of technology, locations and project scales. Video recordings were carried out, using Remotely Operated Vehicles, to identify the environmental impacts of the moorings on the seafloor morphology. That information was completed by side scan sonar campaigns using an Autonomous Underwater Vehicle. The video recordings were useful also to assess the attraction effect of the moorings to epibenthic invertebrates and fishes, whereas the side scan sonar provided quantitative information on the area affected by physical alteration (<1% of the total area occupied by the devices at Armintza and Le Croisic).

Life Cycle Assessment of a wave energy device – LiftWEC

The need to move towards a low-carbon economy has brought about the emergence of various renewable energy sectors, including Marine Renewable Energy (MRE). However, after many years of research and development, the MRE industry still faces challenges in achieving commercial viability, especially regarding wave energy. Whilst it remains possible that successful wave energy technologies exist in the traditional research trend, it is also appropriate to explore alternatives that produce energy by different approaches. Wave-induced lift force devices may be the possibility to move beyond traditional wave energy technologies using diffraction and/or buoyancy forces. In this context arises the LiftWEC, a promising configuration of a lift-based wave energy converter. The LiftWEC device couples with the waves through lift forces generated by two hydrofoils that rotate in a single direction aligned orthogonally to the direction of wave propagation.
 To fully evaluate the overall advantages of this new technology, it is necessary to go beyond the techno-economic performance and reliability. While capable of producing electricity from clean sources, MRE devices are not entirely environmentally friendly, since energy is consumed and pollutants are emitted during their various life cycle stages. Accordingly, as the MRE sector expands, it is important to ensure that the technologies prove to be sustainable alternatives in terms of their environmental impact.
 Life Cycle Assessment (LCA) is a widely recognized methodology to evaluate environmental impacts by considering the technology’s performance over its life cycle. This methodology complies with international standards ISO 14040, which specify the general framework, principles, and requirements for conducting and reporting this type of assessment.
 A “cradle to grave” LCA assessment was applied to the LiftWEC device to evaluate the potential cumulative environmental impacts of the system, complete from the extraction of raw materials until decommissioning. Each stage was analysed within the defined system boundaries, and data on the energy, materials, emissions, and waste products associated were gathered. To allow comparison with other MRE technologies and traditional means of electricity generation, carbon dioxide equivalent emissions per produced electricity (gCO2eq/kWh) were calculated for the study.
 Since ocean energy is broadly considered to contribute to a low-carbon energy system, special attention was given to the LCA results on the global warming potential (GWP). Besides a set of 18 impact categories, Cumulative Energy Demand (CED) and Carbon and Energy payback time (CPT and EPT, respectively) were also analysed. The CPT and EPT are important indicators that measure the time required to offset the carbon emission and demanded energy, respectively, accounted across all development phases of the device.
 This work included the comparison of LCA findings for other MRE devices reported in the literature to validate the viability of the LiftWEC in terms of carbon and energy footprint. In addition, the assessment analysed alternative materials, locations, and recyclability allowing the identification of potential improvement opportunities regarding the reduction of environmental impacts.

The contribution of the SafeWAVE EU project to the future development of ocean energy

The European Atlantic Ocean offers a high potential for marine renewable energy (MRE), which is targeted to be at least 32% of the EU’s gross final consumption by 2030. The European Commission is supporting the development of the ocean energy sector through an array of activities and policies: the Green Deal, the Energy Union, the Strategic Energy Technology Plan (SET-Plan) and the Sustainable Blue Economy Strategy. The nascent status of the MRE sector and Wave Energy (WE) in particular, yields many unknowns about its potential environmental pressures and impacts. Wave Energy Converters’ (WECs) operation in the marine environment is still perceived by regulators and stakeholders as a risky activity. The complexity of MRE licensing processes is also indicated as one of the main barriers to the development of the sector. The lack of clarity of procedures, the varied number of authorities to be consulted and the early stage of Marine Spatial Planning (MSP) implementation are examples of the issues identified that may delay the permitting of the projects. Finally, there is also a need to provide more information on the sector to the general public. Only with an informed society would be possible to carry out fruitful public debates on MRE implementation at the local level. These non-technological barriers that could hinder the future development of WE in EU were addressed by the WESE project funded by EMFF in 2018. The present project builds on the results of the WESE project and aims to move forward through the following specific objectives:
 
 Development of an Environmental Research Demonstration Strategy based on the collection, processing, modelling, analysis and sharing of environmental data collected in WE sites from different European countries where WECs are currently operating (Mutriku power plant and BIMEP in Spain, Aguçadoura in Portugal and SEMREV in France).
 Development of a Consenting and Planning Strategy through providing guidance to ocean energy developers and to public authorities tasked with consenting and licensing of WE projects in France and Ireland; this strategy will build on country-specific licensing guidance and on the application of the MSP decision support tools (i.e. WEC-ERA[1] and VAPEM[2] tools) developed for Spain and Portugal in the framework of the WESE project; the results will complete guidance to ocean energy developers and public authorities for most of the EU countries in the Atlantic Arch.
 Development of a Public Education and Engagement Strategy to work collaboratively with coastal communities in France, Ireland, Portugal and Spain, to co-develop and demonstrate a framework for education and public engagement (EPE) of MRE enhancing ocean literacy and improving the quality of public debates.
 
 The project will finish in September 2023. In this contribution we present the main outcomes, results and lessons learnt during the project.
 [1] https://aztidata.es/wec-era/;
 [2] https://aztidata.es/vapem/

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.

Standardising Marine Renewable Energy Testing: Gap Analysis and Recommendations for Development of Standards

Marine renewable energy (MRE) is still an emerging technology. As such, there is still a lack of mature standards and guidance for the development and testing of these devices. The sector covers a wide range of disciplines, so there is a need for more comprehensive guidance to cover these. This paper builds on a study undertaken in the MaRINET2 project to summarise recommendations and guidance for testing MRE devices and components, by reviewing the recently published guidance. Perceived gaps in the guidance are then discussed, expanding on the previous study. Results from an industry survey are also used to help quantify and validate these gaps. The main themes identified can be summarised as: the development progression from concept to commercialisation, including more complex environmental conditions in testing, accurately modelling and quantifying the power generated, including grid integration, plus modelling and testing of novel moorings and foundation solutions. A pathway to a standardised approach to MRE testing is presented, building on recommendations learnt from the MaRINET2 round-robin testing, showing how these recommendations are being incorporated into the guidance and ultimately feeding into the development of international standards for the marine renewable energy sector.

The Use of Animal-Borne Biologging and Telemetry Data to Quantify Spatial Overlap of Wildlife with Marine Renewables

The growth of the marine renewable energy sector requires the potential effects on marine wildlife to be considered carefully. For this purpose, utilization distributions derived from animal-borne biologging and telemetry data provide accurate information on individual space use. The degree of spatial overlap between potentially vulnerable wildlife such as seabirds and development areas can subsequently be quantified and incorporated into impact assessments and siting decisions. While rich in information, processing and analyses of animal-borne tracking data are often not trivial. There is therefore a need for straightforward and reproducible workflows for this technique to be useful to marine renewables stakeholders. The aim of this study was to develop an analysis workflow to extract utilization distributions from animal-borne biologging and telemetry data explicitly for use in assessment of animal spatial overlap with marine renewable energy development areas. We applied the method to European shags (Phalacrocorax aristotelis) in relation to tidal stream turbines. While shag occurrence in the tidal development area was high (99.4%), there was no overlap (0.14%) with the smaller tidal lease sites within the development area. The method can be applied to any animal-borne bio-tracking datasets and is relevant to stakeholders aiming to quantify environmental effects of marine renewables.

Parametric design of a resonant point absorber with a fully submerged toroidal shape

The parametric design of a resonant point absorber, equipped with a fully submerged toroidal shape and connected to a permanent magnet linear generator lying on the seabed, is performed to investigate the effectiveness of the new WEC device in terms of power production and cost of energy. After developing a non-linear time-domain model for the heave, surge and pitch motions of the floating buoy and the vertical motion of the Power Take-Off translator mass, a comparative analysis is performed among a reference WEC device and the new layout. The Annualised Energy Production of the WEC devices is assessed with reference to a candidate deployment site located in the western Mediterranean Sea. The scantling of the tensioned line, connecting the floating buoy to the Power Take-Off unit, is carried out based on both Ultimate and Fatigue Limit State design conditions. Subsequently, the Levelised Cost of Energy is determined and a sensitivity analysis is performed to detect a possible pathway to further reduce the power production costs. Based on current results, the new WEC device seems to be a promising layout to gain the EU target for the marine renewable energy sector that should be reached by 2025.

Marine Biofouling: A European Database for the Marine Renewable Energy Sector

Biofouling is a major problem shared among all maritime sectors employing submerged structures where it leads to substantially increased costs and lowered operational lifespans if poorly addressed. Insight into the ongoing processes at the relevant marine locations is key to effective management of biofouling. Of specific concern for the marine renewable energy (MRE) sector is the fact that information on biofouling composition and magnitude across geographies is dispersed throughout published papers and consulting reports. To enable rapid access to relevant key biofouling events the present work describes a European biofouling database to support the MRE sector and other maritime industries. The database compiles in one document qualitative and quantitative data for challenging biofouling groups, including non-native species associated with MRE and related marine equipment, in different European Ecoregions. It provides information on the occurrence of fouling species and data on key biofouling parameters, such as biofouling thickness and weight. The database aims to aid the MRE sector and offshore industries in understanding which biofouling communities their devices are more susceptible to at a given site, to facilitate informed decisions. In addition, the biofouling mapping is useful for the development of biosecurity risk management plans as well as academic research.

Combined Exploitation of Offshore Wind and Wave Energy in the Italian Seas: A Spatial Planning Approach

The opportunity to co-locate wind and wave energy exploitation is analysed in the Italian seas grounding on the rationale that benefits are greater when un-correlated resources are combined. The study shows that, although waves and winds are generally strongly correlated, in some conditions their correlation is lower and the combined energy harvesting more interesting. As spatial conflicts of sea use and demand for maritime space are increasingly growing, the development of the marine renewable energy sector needs to be evaluated in the perspective of the complex framework of existing uses, pressures and foresees developments. The early prediction of the areas of potential conflicts creates in fact the ground for mitigation actions or early negotiations between stakeholders. In this study the opportunity of co-locating offshore wind turbines and wave energy converters is analysed through a spatial planning approach. Both the potential for combining different renewable technologies, and the impact associated to such development was considered in the context of the existing pressures (e.g. naval traffic; mariculture activities; submarine cables routes; dredg spoils dumping; offshore activities; windfarms and ocean energy projects) and vulnerabilities (Marine Protected Areas, Key habitat presence) through quantitative indicators. The western coast off Sardinia island, the southern areas of Pantelleria island and the Tunisian coastal waters appear to be the most suitable sites. The study shows how quantitative spatial planning methods may support the selection of the sites of potential interest for the marine renewable energy sector in the perspective of cost-effectiveness and environmental impact minimization.

Marine Renewable Energy Clustering in the Mediterranean Sea: The Case of PELAGOS Project

The main ideas presented in this work are an outcome of the Interreg MED project PELAGOS (Promoting innovative nEtworks and cLusters for mArine renewable energy synerGies in Mediterranean cOasts and iSlands). Since Blue Energy development is at its very beginning in the Mediterranean Sea, the aim of the paper is to present and discuss in depth the key-issues for a Marine Renewable Energy (MRE) cluster development in the Mediterranean and reveal its necessity for the commercial and sustainable development of Blue Energy in the area. This cluster is expected to stimulate the relevant Blue Energy sectors, under the perspective of smart and sustainable growth. A healthy cluster is based on an efficient cluster policy. The main policy constituents (innovation, legislation and financial frameworks) are discussed taking into account the interrelated characteristics that are expected to specify the commercial development of MRE in the area. Key issues that can contribute to the establishment and acceleration of deployment of the related technological innovation are identified, and existent hindrances and challenges encountered in MRE sector are determined. The importance of solid financing instruments and strong collaborations among interested stakeholders is also highlighted for the viability of the MRE cluster. Finally, as an example of the cluster activities at a national level, the Greek Hub for Blue Energy, is introduced. In this respect, aspects in terms of its structure and the services provided to its members are analysed.

Detection of Visual Signatures of Marine Mammals and Fish within Marine Renewable Energy Farms using Multibeam Imaging Sonar

Techniques for marine monitoring have been greatly evolved over the past decades, making the acquisition of environmental data safer, more reliable and more efficient. On the other hand, the marine renewable energy sector has introduced dissimilar ways of exploring the oceans. Marine energy is mostly harvested in murky and high energetic places where conventional data acquisition techniques are impractical. This new frontier on marine operations brings the need for finding new techniques for environmental data acquisition, processing and analysis. Modern sonar systems, operating at high frequencies, can acquire detailed images of the underwater environment. Variables such as occurrence, size, class and behavior of a variety of aquatic species of fish, birds, and mammals that coexist within marine energy sites can be monitored using imaging sonar systems. Although sonar images can provide high levels of detail, in most of the cases they are still difficult to decipher. In order to facilitate the classification of targets using sonar images, this study introduces a framework of extracting visual features of marine animals that would serve as unique signatures. The acoustic visibility measure (AVM) is here introduced as technique of identification and classification of targets by comparing the observed size with a standard value. This information can be used to instruct algorithms and protocols in order to automate the identification and classification of underwater targets using imaging sonar systems. Using image processing algorithms embedded in Proviwer4 and FIJI software, this study found that acoustic images can be effectively used to classify cod, harbour and grey seals, and orcas through their size, shape and swimming behavior. The sonar images showed that cod occurred as bright, 0.9 m long, ellipsoidal targets shoaling in groups. Harbour seals occurred as bright torpedo-like fast moving targets, whereas grey seals occurred as bulky-ellipsoidal targets with serpentine movements. Orca or larger marine mammals occurred with relatively low visibility on the acoustic images compared to their body size, which measured between 4 m and 7 m. This framework provide a new window of performing qualitative and quantitative observations of underwater targets, and with further improvements, this method can be useful for environmental studies within marine renewable energy farms and for other purposes.

Experimental modelling of mooring systems for floating marine energy concepts

New floating devices are emerging thanks to a highly active marine renewable energy sector. These concepts, featuring floating offshore wind installations as well as other projects in the wave energy sector require innovative mooring systems. Therefore, a complete analysis of this element is required to achieve a successful design.This paper investigates the behaviour of mooring systems based on catenary configuration thanks to a detailed experimental program. Tests to characterize the properties of the mooring lines, and geotechnical and hydrodynamic trials were also performed on a 1:40 laboratory scale. Mooring truncation problem is normally faced by the researchers working on model testing of mooring lines in deep water, because the depth of the lab is typically small. However, it does not seem to be a problem for offshore floating renewable energy devices which are usually in relatively shallow water. The influence of catenary weight, imposed displacements at the fairlead, wave-current loads and different types of sea bottom friction on the mooring systems were analysed in terms of tensions, movements and shape of force-displacement curve. However, scaling of the sea bottom and the mooring line interaction is a challenge. Although the damping effect was investigated and compared under different movement conditions, the conclusions achieved can be upscale to real scale but it must be noticed that there are limitations due to scale effect issues. A total of 111 test were performed. The influence of the hydrodynamic inertia and drag is negligible on long wave and slow motions, while they have more importance during shorter waves and quick motions. The results reveal the importance of acceleration in the movement being possible to distinguish dynamic and quasi-static performance depending on the acceleration of the mooring line.

Considerations for dealing with unexploded ordnance on maritime engineering projects

Huge areas of the seabed and many shores around the world have, at one time or another, been subject to some form of military activity, which has left an unwelcome legacy of unexploded ordnance (UXO) within the marine environment. With an ever-increasing number of maritime engineering projects being developed, especially with the rapid growth of the marine renewable energy sector, the prospect of potentially hazardous encounters with UXO is a matter that demands serious consideration. The threat of UXO being present within, or in close proximity to, a project site can lead to significant safety, environmental and economic risks that need to be adequately assessed and managed. This paper presents an assimilation of the present state of scientific knowledge and collates examples of good practice and latest international guidance and standards from a wide range of literature sources to provide discussion of practical considerations concerning the assessment and management of UXO containing high explosives. A background to the issues surrounding the legacy presence of UXO in the marine environment is presented for context, together with a framework for the assessment and management of the risks posed to various marine activities.

Assessing the performance durability of elastomeric moorings: Assembly investigations enhanced by sub-component tests

The growing marine renewable energy sector has led to a demand for increasingly compliant mooring systems. In response, several innovative mooring tethers have been proposed demonstrating potential customisation to the stiffness profile and reduced peak mooring loads. Many of these novel systems utilise materials in a unique application within the challenging marine environment and their long term durability remains to be proven.This paper presents a multifaceted investigation into the durability of a novel polyester mooring tether with an elastomeric core. Laboratory based functionality tests are repeated on tether assemblies following a 6 month sea deployment. Results show a 45% average increase in dynamic axial stiffness. This is supported by high tension laboratory based fatigue endurance tests showing a peak increase in dynamic axial stiffness of 42%. Sub-component material tests on the core elastomer support the assembly tests, separately demonstrating that certain aspects of tether operation lead to increased material sample stiffness. The average increase in material radial compressive stiffness is 22% and 15% as a result of marine ageing and repeated mechanical compression respectively; these are the first results of this type to be published.The performance durability characterisation of the tether establishes the mooring design envelope for long-term deployment. This characterisation is crucial to ensure reliable and effective integration of novel mooring systems into offshore engineering projects.

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.