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Offshore multi-purpose platforms for a Blue Growth: A technological, environmental and socio-economic review
Abstract
“Blue Growth” and “Blue Economy” is defined by the World Bank as: “the sustainable use of ocean resources for economic growth, improved livelihoods and jobs, while preserving the health of ocean ecosystem”. Multi-purpose platforms (MPPs) can be defined as offshore platforms serving the needs of multiple offshore industries (energy and aquaculture), aim at exploiting the synergies and managing the tensions arising when closely co-locating systems from these industries.
Despite a number of previous projects aimed at assessing, from a multidisciplinary point of view, the feasibility of multipurpose platforms, it is here shown that the state-of-the-art has focused mainly on single-purpose devices, and adopting a single discipline (either economic, or social, or technological, or environmental) approaches. Therefore, the aim of the present study is to provide a multidisciplinary state of the art review on, whenever possible, multi-purpose platforms, complementing it with single-purpose and/or single discipline literature reviews when not possible. Synoptic tables are provided, giving an overview of the multi-purpose platform concepts investigated, the numerical approaches adopted, and a comprehensive snapshot classifying the references discussed by industry (offshore renewables, aquaculture, both) and by aspect (technological, environmental, socio-economic). The majority of the multi-purpose platform concepts proposed are integrating only multiple offshore renewable energy devices (e.g. hybrid wind-wave), with only few integrating also aquaculture systems. MPPs have significant potential in economizing CAPEX and operational costs for the offshore energy and aquaculture industry by means of concerted spatial planning and sharing of infrastructure.
... Simultaneously, there is growing need for alternative food production and security, where aquaculture of lower trophic groups such as bivalves and seaweed, are of particular interest to policy makers as it does not exacerbate pressures on terrestrial ecosystems typical of agriculture such as land use change, fertiliser usage and coupled carbon emissions alongside depletion of freshwater (Anderson et al., 2017;European Commission, 2021;Garlock et al., 2022). The offshore Multi-use Setting (MUS) refers to the planning and engineering concept of co-locating or co-developing 1 marine industrial activities together including energy infrastructure and aquaculture, and thus is a solution contributing to both food and energy security challenges from the same ocean space (Abhinav et al., 2020;Steins et al., 2021). Wind farms sited in offshore regions i.e. away from land and coastal areas, presents an optimal solution to generate renewable energy with favourable conditions for maximising energy yields (Dincer et al., 2021;Barooni et al., 2022) and bypassing the social barrier of "NIM-BYISM", a phrase used to capture the rejection of visually displeasing projects by local residents (Bates and Firestone, 2015;Susskind et al., 2022). ...
... Wind farms sited in offshore regions i.e. away from land and coastal areas, presents an optimal solution to generate renewable energy with favourable conditions for maximising energy yields (Dincer et al., 2021;Barooni et al., 2022) and bypassing the social barrier of "NIM-BYISM", a phrase used to capture the rejection of visually displeasing projects by local residents (Bates and Firestone, 2015;Susskind et al., 2022). However, the fixed structures of wind farms typically result in the exclusion of other marine stakeholders, such as large pelagic fisheries and shipping and carry detrimental impacts to ocean ecology including species mortality and general biological disturbance (Abhinav et al., 2020;Galparsoro et al., 2022). Proponents of MUS advocate that including alternative industries within these zones will mean efficient utilisation of space that would otherwise not be used by other marine stakeholders, thus reducing competition for spatial resource by expanding activities in the burgeoning marine economy (Abhinav et al., 2020). ...
... However, the fixed structures of wind farms typically result in the exclusion of other marine stakeholders, such as large pelagic fisheries and shipping and carry detrimental impacts to ocean ecology including species mortality and general biological disturbance (Abhinav et al., 2020;Galparsoro et al., 2022). Proponents of MUS advocate that including alternative industries within these zones will mean efficient utilisation of space that would otherwise not be used by other marine stakeholders, thus reducing competition for spatial resource by expanding activities in the burgeoning marine economy (Abhinav et al., 2020). Furthermore, aquaculture and wind farm co-location has been pitched in Europe as a sustainable development pathway with claimed improvements to sustainability including, but are not limited to, marine conservation, economic cost reductions and growth, and enhancing stakeholder rights (Przedrzymirska et al., 2021). ...
... Since then, MU has evolved into a trendy marine policy concept. Scholars and practitioners alike believe that it has the potential to create new economic opportunities and achieve economies of scale 9,[12][13][14][15][16] . Beyond fostering growth, the combination of human activities at sea is also intended to mitigate conflicts over space and resources [17][18][19][20][21][22] , as well as alleviate human pressures on marine ecosystems 18,19,23,24 . ...
... In the scientific literature, MU is formally defined as the co-location of complementary activities at sea 25,26 , their clustering 16 , or their combination 13,21,27 . Some authors emphasize distinctions, such as "multi-use platforms" (MUP) versus "multi-use of space" (MUS) 13,14,28 . Others differentiate between "hard" and "soft" multi-use, with a focus on the presence or absence of infrastructures [18][19][20]24,29 . ...
... It co-financed several largescale applied science projects with the objective of identifying and assessing the most promising combinations of marine uses. These projects had a dual focus: one on developing innovative multipurpose offshore platform concepts and the other on exploring synergies among co-located activities at sea, outlining two different, yet complementary, approaches to MU 13,14,28 . MUSES evaluated 17 different combinations, including pescatourism -a practice and research field that had evolved independently from MU. ...
This paper offers a comprehensive, analytical, and critically informed overview of the current state of ocean multi-use research. It delves into the origins, trajectory, and driving forces behind this emerging research field, all within the broader context of investigations addressing the management of increasingly diverse and intensifying activities at sea. The Bibliometrix R package is employed to analyze the social, geographical, and conceptual dimensions of multi-use scientific production. The results obtained are then compared to a larger corpus of publications focusing on both multiple-use Marine Protected Areas (MPAs) and Marine Spatial Planning (MSP). Finally, the paper addresses research gaps, with a particular emphasis on the transdisciplinary challenges associated with translating this new marine policy concept into practical implementation and extending its application beyond European seas.
... Defined as the intentional joint use of resources in close geographic proximity by complementary marine uses or users [1,2], ocean multi-use recently emerged as a marine policy concept promoting Blue Growth [3,4]. This novel idea gained popularity over the last decade among scientists and marine planners in Europe. ...
... If the European Commission has been reluctant to give multi-use political recognition, it actively promoted it through its successive research and innovation framework programs 4 . It funded large scale applied research projects investigating, assessing and promoting multi-use. ...
... This diversity makes this concept difficult to circumscribe and define, especially since different terms exist to describe marine uses combinations, such as multiple use, co-use or colocation [13]. Some researchers distinguish multi-use platforms (MUP) from multi-use of space (MUS) [14,3,4], other "soft" from "hard" multi-use taking respectively into account the absence or presence of infrastructures [15][16][17][18][19]. Schupp et al. proposed a typology classifying the degree of connection between uses according to functional, provisioning, spatial and temporal criteria [15]. Multi-use diversity can also be sorted out by considering the uses involved, their combinations, their spatial relationships, as well as social, economical and environmental objectives. ...
Defined as the intentional joint use of resources in close geographic proximity by complementary marine uses or users, ocean multi-use recently emerged as a marine policy concept promoting Blue Growth. This novel idea gained popularity over the last decade among scientists and marine planners in Europe. Several projects are currently dedicated to foster multi-use and to streamline it into marine spatial planning policies. Theoretically, combining marine uses is a rationale and integrated approach to maritime spaces' management maximizing economical profits while reducing conflicts and supporting sustainable development. In practice, it mainly supports the development of new ocean uses such as marine renewable energies, offshore aquaculture and fishing-based tourism. Therefore, ocean multi-use not only meets Blue Growth's promise, but also current trends shaping marine spaces' appropriation, occupation and exploitation. The rise of ocean multi-use in marine policies echoes critical debates about limits to Blue Growth. Even if an emerging substantial body of literature on ocean multi-use already exists, this concept remains doubtful when developed in practice: Is it capable to combine economic, social and environmental goals? Is ocean multi-use increasing or reducing spatial pressures on marine spaces Who are multi-use winners and losers? etc. This paper aims at contributing to feed a debate still in its infancy with Multi-Frame's preliminary results (systematic review of the scientific literature and bibliometric analysis. This project (2020-2023) aims at investigating, assessing and promoting multi-use in a global perspective 1. Firstly, we will trace the history of this concept, explaining the role of science and marine policies in exploring and promoting synergies between human activities at sea. Secondly, we will analyze multi-use rationale by confronting social, economical, environmental and spatial arguments supporting multi-use with the results of applied research projects. We will discuss ocean multi-use narratives within the broader context of the limits to Blue Growth and their implications for governing, steering and managing the blue realm.
... Defined as the intentional joint use of resources in close geographic proximity by complementary marine uses or users [1,2], ocean multi-use recently emerged as a marine policy concept promoting Blue Growth [3,4]. This novel idea gained popularity over the last decade among scientists and marine planners in Europe. ...
... If the European Commission has been reluctant to give multi-use political recognition, it actively promoted it through its successive research and innovation framework programs 4 . It funded large scale applied research projects investigating, assessing and promoting multi-use. ...
... This diversity makes this concept difficult to circumscribe and define, especially since different terms exist to describe marine uses combinations, such as multiple use, co-use or colocation [13]. Some researchers distinguish multi-use platforms (MUP) from multi-use of space (MUS) [14,3,4], other "soft" from "hard" multi-use taking respectively into account the absence or presence of infrastructures [15][16][17][18][19]. Schupp et al. proposed a typology classifying the degree of connection between uses according to functional, provisioning, spatial and temporal criteria [15]. Multi-use diversity can also be sorted out by considering the uses involved, their combinations, their spatial relationships, as well as social, economical and environmental objectives. ...
Defined as the intentional joint use of resources in close geographic proximity by complementary marine uses or users, ocean multi-use recently emerged as a marine policy concept promoting Blue Growth. This novel idea gained popularity over the last decade among scientists and marine planners in Europe. Several projects are currently dedicated to foster multi-use and to streamline it into marine spatial planning policies. Theoretically, combining marine uses is a rationale and integrated approach to maritime spaces' management maximizing economical profits while reducing conflicts and supporting sustainable development. In practice, it mainly supports the development of new ocean uses such as marine renewable energies, offshore aquaculture and fishing-based tourism. Therefore, ocean multi-use not only meets Blue Growth's promise, but also current trends shaping marine spaces' appropriation, occupation and exploitation. The rise of ocean multi-use in marine policies echoes critical debates about limits to Blue Growth. Even if an emerging substantial body of literature on ocean multi-use already exists, this concept remains doubtful when developed in practice: Is it capable to combine economic, social and environmental goals? Is ocean multi-use increasing or reducing spatial pressures on marine spaces Who are multi-use winners and losers? etc. This paper aims at contributing to feed a debate still in its infancy with Multi-Frame's preliminary results (systematic review of the scientific literature and bibliometric analysis. This project (2020-2023) aims at investigating, assessing and promoting multi-use in a global perspective 1. Firstly, we will trace the history of this concept, explaining the role of science and marine policies in exploring and promoting synergies between human activities at sea. Secondly, we will analyze multi-use rationale by confronting social, economical, environmental and spatial arguments supporting multi-use with the results of applied research projects. We will discuss ocean multi-use narratives within the broader context of the limits to Blue Growth and their implications for governing, steering and managing the blue realm.
... Offshore Multiuse Setting (MUS) refers to the planning and engineering concept of co-locating or codeveloping 1 marine industrial activities including wind farms, aquaculture, and tourism (Abhinav et al., 2020;Steins et al., 2021). The immediate advantage of implementing the MUS is the e cient use of space in the burgeoning marine economy; an economy that is predicted to grow at double the rate of the mainstream economy by 2030(European Commission, 2021a) and thus is likely to increase competition among stakeholders for marine resources in the coming decade(s) (Hodgson et al., 2019;European Commission, 2021b). ...
... The decision to proceed with implementing the MUS has the traits of a complex decision problem (Hemming et al., 2022) with multiple objectives to satisfy (Abhinav et al., 2020), uncertainty of outcomes and risk concerns (O'Shea et al., 2022; van den Burg et al., 2020). Therefore, the offshore Multiuse Setting will bene t from taking a structured decision-making approach (a process of collaborative, facilitated group-deliberation methods to multiple objective decisions) (Gregory et al., 2012) and integrative assessment modelling techniques (qualitative and quantitative techniques combining social and natural dimensions) (Abhinav et al., 2020;O'Shea et al., 2022). ...
... The decision to proceed with implementing the MUS has the traits of a complex decision problem (Hemming et al., 2022) with multiple objectives to satisfy (Abhinav et al., 2020), uncertainty of outcomes and risk concerns (O'Shea et al., 2022; van den Burg et al., 2020). Therefore, the offshore Multiuse Setting will bene t from taking a structured decision-making approach (a process of collaborative, facilitated group-deliberation methods to multiple objective decisions) (Gregory et al., 2012) and integrative assessment modelling techniques (qualitative and quantitative techniques combining social and natural dimensions) (Abhinav et al., 2020;O'Shea et al., 2022). However, to date, few attempts have been made in this direction (Abhinav et al., 2020;O'Shea et al., 2022). ...
The offshore Multiuse Setting (MUS) is a concept that seeks to co-locate marine industrial activities including wind farms, aquaculture, and tourism. MUS are thought to be an innovative way to promote efficiency in resource use. Despite this contention, plans for MUS are plagued by an implementation gap whereby innovative ideas do not actualise into commercial operations. A suggested barrier to progression of MUS is the lack of understanding surrounding the consequences to economic, societal and environmental dimensions of the system that result from MUS designs and activities. The implementation of a MUS has the traits of a complex decision problem and thus will benefit from decision analysis to structure the decision-making process. Here we show the consequences resulting from implementation of the Multiuse Setting concept against multiple objectives - environmental, social, and economic – through the application of group-based cognitive mapping. The assessment involved the use of a hypothetical case study to introduce system boundaries and explored predictions about the outcomes of implementation using a modified Delphi method approach. The results demonstrate that there are a network of social-ecological changes with both positive and negative (and potentially costly) implications across and within sustainability dimensions. We illustrate how systemic views contradict existing claims about seaweed aquaculture and co-location with wind farms, such as carbon sequestration potential and spatial resource efficiency, considering the complexity of an MUS project. The methodology provides a route to recognise trade-offs and risks from, and provide alternative strategies for, the MUS and wider seaweed aquaculture within the context of the broader industrial strategy of Sustainable and Circular Bioeconomy transition.
... Already addressing the rising potential for competition among ocean industries, several EU projects have already investigated the potential for ocean multi-use, and even multi-purpose platform concepts [12,13]. For instance, Van den Burg et al. [14] report on the geographic potential of alternative multi-use concepts, by reviewing what area is available for specific types of ocean structures as determined by bathymetric constraints and distance to shore. ...
... Our paper contributes to the understanding of where marine spatial competition is most likely to prevail, and thereby can serve as recommendations on where to focus efforts for co-existence both between industries, and between industries and nature. Combined floating offshore wind structure and finfish cage aquaculture [12,13]. Floating desalination plant powered by wave power [12,13,21]. ...
... Combined floating offshore wind structure and finfish cage aquaculture [12,13]. Floating desalination plant powered by wave power [12,13,21]. Energy islands acting as hubs for grid connection and green hydrogen production plants [1,3,4]. ...
This paper reports on recent results on the race for space in our ocean, based on DNVs forecasting efforts into the Blue Economy. We find that the world will see a large increase in the usage of ocean area by offshore installations for energy and food production, with the European area for installations growing close to five-fold to 2050. If not carefully managed, the energy transition in the ocean risks triggering a race for space and conflicts with other stakeholders. By introducing the Spatial Competition Index (SCI), we propose a new indicator to measure the level of competition among ocean industries and nature. SCI forecasts to 2050 reveal that shallow waters close to shore will face significant increases in pressure from ocean industries. This indicates that there is a need for co-existence to be considered in new offshore wind development projects, and for developers to increasingly consider floating structures.
... It is therefore important to highlight the early TRL stage of OTEC technology and the importance of studies, especially those with customized component mounting systems [79,80]. Other options for the OTEC Ecopark include (1) multi-use offshore platforms, as proposed for aquaculture and marine energy co-location [82], for example the Blue Growth Farm project funded by the European Comission [83], and (2) the use of the Very Large Floating Structure, which has been considered for energy production [84]. ...
... tems [79,80]. Other options for the OTEC Ecopark include (1) multi-use offshore platforms, as proposed for aquaculture and marine energy co-location [82], for example the Blue Growth Farm project funded by the European Comission [83], and (2) the use of the Very Large Floating Structure, which has been considered for energy production [84]. ...
... In addition, the sizing of the OTEC plant must be consistent with the size of the population and its demands. Other multi-purpose projects on offshore platforms such as Daguan, Daranshan, and Sehngshan in China have demonstrated the great potential of marine energy to serve remote and isolated communities, providing them not only with a sustainable, safe, and affordable energy source but also with socio-economic benefits such as food and jobs [83]. ...
... The sustainable use of various forms of renewable energy in the marine environment-e.g., wind, waves, tides, and currents-can be important in any plans to slow down the harmful impacts of climate change [1]. Bottom-supported offshore wind turbines are commercially mature, but the demand for floating offshore wind turbines (FOWTs) has increased because many resource-rich sites are in deeper waters, where they are also accompanied by stronger high-quality offshore winds and limited visual or social impacts farther out from the shore [1,2]. ...
... The sustainable use of various forms of renewable energy in the marine environment-e.g., wind, waves, tides, and currents-can be important in any plans to slow down the harmful impacts of climate change [1]. Bottom-supported offshore wind turbines are commercially mature, but the demand for floating offshore wind turbines (FOWTs) has increased because many resource-rich sites are in deeper waters, where they are also accompanied by stronger high-quality offshore winds and limited visual or social impacts farther out from the shore [1,2]. To achieve installed offshore wind capacity and deployment targets, it is necessary to lower the overall energy generation cost of FOWTs. ...
... For action Stay, the outcomes are the same as n = 1 case; (3,4) transitions to (4,5) or to (0, 5). For action Go, (3,4) transitions to (5, 0) if an n-favorable situation results, to (0, 6) for both BFFFBB and BFFFFB; and to (1,6) for BFFFBF. ...
In an emerging “blue economy,” the use of large multipurpose floating platforms in the open ocean is being considered. Such platforms could possibly support a diversified range of commercial activities including energy generation, aquaculture, seabed mining, transport, tourism, and sea-based laboratories. A Markov Decision Process (MDP) framework is proposed to deal with operations and maintenance issues that are inevitable; challenges arise from the complex stochastic weather conditions that need to be accounted for. Using data as well as contrasting synthetic simulations of relevant weather variables, we demonstrate the robustness/versatility of the MDP model. Two case studies-one involving constant and another involving time-dependent downtime costs-are conducted to demonstrate how the proposed MDP framework incorporates weather patterns from available data and can offer optimal policies for distinct metocean conditions (i.e., temporal variations in the weather). A realistic example that illustrates the implementation of the proposed framework for multiple O&M issues involving salmon net pens and wave energy converters demonstrates how our optimal policies can minimize O&M costs and maximize crew safety almost as if the true future were known for scheduling.
... Multi-use between these two sectors enables a reduction in CAPEX (Capital Expenditure) and OPEX (Operating Expenditure) and optimizes production per area (Astariz et al., 2015b;Weiss et al., 2018a). Legislative synergies and similarity in terms of environmental, administrative and technological constraints also support the combined exploitation (Abhinav et al., 2020;Pérez-Collazo et al., 2015). Another advantage of co-located farms is that the renewable energy source is more predictable and less variable (Gaughan and Fitzgerald, 2020). ...
... Nevertheless, this case study assumes the inherent difficulty in determining compatibility based on stakeholder opinion and hypothetical scenarios. Rapid technological development in the maritime sector (Abhinav et al., 2020), as well as the specific location, type of project and technology employed can alter spatial compatibility assessments. ...
Blue Growth highlights the need for integrated management approaches and strategic planning to minimize conflicts and optimize the use of space. This study analyzes the spatial compatibility between existing uses and potential zones for emerging activities in the Exclusive Economic Zone of Southern Brazil. The proposed methodology was based on a three-step approach: (i) spatial analysis to identify possible zones of overlap between emerging activities (i.e., wind energy, wave energy, aquaculture and mining) and existing uses. (ii) Consultation with MSP experts and key stakeholders through an online survey based on the Delphi method. (iii) Application of the survey responses, using the Analytic Hierarchy Process, to generate a Spatial Compatibility Index. The combination of wind and wave energy was the most compatible interaction found. Aquaculture shows low compatibility with other uses, due to the sensitivity of farming live species. Mining also showed low compatibility, mainly due to the risks involved in its operation. This contribution shows the possible spatial conflicts and synergies from a stakeholder perspective. This methodological approach aims to boost sustainable development in the marine environment, driving multi-use and reducing the impact associated to the exploitation of different activities.
... Their life-cycle assessment found that the primary source of pollution occurred during manufacturing of the platform and the decommissioning costs were affected depending on the recyclability of the platform parts. Abhinav et al. [16] reviewed platforms integrating multiple renewable energy generation sources with co-located aquaculture systems. The study concluded that such systems are still at a low technology readiness level (TRL), with multi-purpose platforms still being far from common practice. ...
... The assumed business model is to have this area owned by the operators of the FBWs, but leased to a third party operating the facilities. In order to 16 Table 22 presents the assumed pricing being assumed in the presented study. These are presented at the price per day for yachts as a function of vessel size. ...
Previous research has proven that one of the fundamental requirements for ensuring increased profitability and economic competitiveness of offshore-based projects is co-locating different technologies within the same marine space. This paper presents a number of techno-feasibility analyses for floating offshore technologies for the Maltese Islands, located in the Central Mediterranean Sea. The first part compares the feasibility of offshore-based solar photovoltaic prices with those onshore, taking into consideration Malta’s land prices. The second part considers the use of a novel floating breakwater design that integrates energy storage. The breakwater is used to create a sheltered water area in deep waters for a multi-use marine park. Different revenue streams for the floating break water are considered, including renting the sheltered marine space out to operators of floating solar farms, aquaculture cages and vessel berthing facilities, and the provision of energy storage services. It is found that the combined income from the multiple revenue streams is still insufficient to justify the investment and that financially support from Government is essential to render the floating breakwaters viable.
... In addition, a fit-for-purpose assessment regarding targeted information products is often missing [13]. Second, recent research reveals several emerging application areas related to OWF which need extensive monitoring, e.g., multi-use of OWF platforms [16], wake and lee effects of OWFs on atmosphere and ocean environment [17][18][19][20], monitoring for sea bed cable protection [21,22], contamination caused by OWF [23,24], and OWF-related security issues [25][26][27][28]. Observation requirements and adequacy analysis are rarely performed in these emerging application areas. ...
... Observation requirements and gap analysis of OWF siting have been investigated in previous studies [13]. The multi-use of OWF has been an intensive research area in the EU research framework FP7, Horizon 2020, and Horizon Europe [16]. The observation requirements for multi-use are related not only to OWF applications but also to specific co-utilization, e.g., aquaculture farms and tourism. ...
The rapid expansion of offshore wind farms (OWFs) in European seas is accompanied by many challenges, including efficient and safe operation and maintenance, environmental protection, and biodiversity conservation. Effective decision-making for industry and environmental agencies relies on timely, multi-disciplinary marine data to assess the current state and predict the future state of the marine system. Due to high connectivity in space (land–estuarial–coastal sea), socioeconomic (multi-sectoral and cross-board), and environmental and ecological processes in sea areas containing OWFs, marine observations should be fit for purpose in relation to multiple OWF applications. This study represents an effort to map the major observation requirements (Part-I), identify observation gaps, and recommend solutions to fill those gaps (Part-II) in order to address multi-dimension challenges for the OWF industry. In Part-I, six targeted areas are selected, including OWF operation and maintenance, protection of submarine cables, wake and lee effects, transport and security, contamination, and ecological impact assessments. For each application area, key information products are identified, and integrated modeling–monitoring solutions for generating the information products are proposed based on current state-of-the-art methods. The observation requirements for these solutions, in terms of variables and spatial and temporal sampling needs, are therefore identified.
... An offshore multipurpose floating platform (MPFP) combines different marine technologies to serve industry needs within one infrastructure, aiming at enlarging the synthesis benefits and reducing negative impacts. By integrating multiple offshore technologies, such as offshore renewable energy, aquaculture, leisure, and transport, an MPFP could have many significant benefits in terms of economic efficiency, spatial planning optimization, and environmental risk avoidance (Abhinav et al., 2020). ...
... Even though offshore renewable energy and aquaculture have matured as separate technologies, the environmental impacts when these sectors are combined are poorly understood and almost entirely based on theoretical projections. The TROPOS project studied the effects of combining offshore renewable energy with aquaculture in the MPFP, concluding that the multipurpose approach had the advantage of integrating diverse activities in the same location when compared with the single approach (Abhinav et al., 2020). Golman et al. (2014) also summarized the environmental impacts of the TROPOS platform following an environmental impact assessment (EIA) procedure, identifying some environmental synergies among different sectors. ...
An offshore multipurpose floating platform (MPFP) combines different marine technologies to serve industry needs using one infrastructure; the aim of an MPFP is enlarging the synthesis benefits and reducing the negative impacts. Ocean thermal energy conversion (OTEC) in particular has attracted significant attention for its great potential and low environmental risk. This research demonstrates the system design of a conceptual MPFP in the South China Sea, evaluating its economic and environmental sustainability using an inclusive index. The system is based on a modular floating structure with a designed lifetime of 50 years. Tuna aquaculture, microalgae cultivation and processing, and the OTEC energy infrastructure are integrated to increase the profitability of the applications. We adopted a high-yield photobioreactor microalgae cultivation system and a low-cost barge-type floating structure combined with a semisubmergible to reduce the required area and cost of the floating structure and improve the sustainability of the system. The inclusive impact index “Triple-I-light (IIIlight)” was calculated to evaluate the environmental sustainability and economic feasibility of the floating system. The result shows that the new system becomes environmentally neutral (EF = BC) at a lifetime of 11.5 years, showing sustainability (IIIlight ≤ 0) at a lifetime of 20 years. The proposed system can produce fish with no external energy or feed supply. An autonomous system, such as the one proposed here, is considered very effective when it comes to utilizing the ocean and contributing to a sustainable society.
... The best-known example of these are multi-purpose platforms (MPPs), also called multi-use platforms (MUPs), which are offshore platforms serving the needs of multiple offshore industries (e.g., energy and aquaculture). These platforms exploit the synergies and manage the tensions when systems from these industries are closely collocated [5]. ...
... Of the 23 papers classified, 22 proposed a mobile solution. Financial considerations emerge in literature when M3 applications are discussed [5,40,[60][61][62][63][64][65][66]. This is confirmed by the term "cost" appearing among the top-scoring keywords, contrary to M1 and M2 applications, where "cost" was not among the top 20 keywords. ...
Multi-purpose offshore infrastructure, integrated with various user functions within the same space, is increasingly hailed as a way to address issues arising from multiple demands placed on coasts and seas. In this paper, we review how recent literature addresses the conditions enabling marine-multifunctional-modular-mobile (M4) solutions' contribution to a sustainable transition in the provision of critical services on islands and along coastlines. We are particularly interested in understanding the synergies and the most common themes surrounding their deployment as analyzed in previous research. We find that mobility and modularity have been less researched compared to multifunctionality of marine applications, despite the benefits these could have in decreasing operation costs and improving resiliency in coastal environments. With multifunctionality, wave-wind is the most common combination of services, followed by wind-aquaculture and wave-aquaculture. However, so far, the literature has mostly focused on European marine applications of this kind, so there need to be explorations of other methodologies that capture other regions, as well as explorations of nonscientific literature. We recommend more detailed evaluations of impacts, benefits, drawbacks, and institutional frameworks needed for realizing mobile and modular multifunctional applications in marine environments.
... Low-trophic species have been considered for co-located offshore aquaculture including European flat oysters (Ostrea edulis), blue mussels (Mytilus edulis), and brown seaweeds (e.g., Laminaria digitata; Buck & Langan, 2017). Existing feasibility assessments of offshore aquaculture and co-locating aquaculture with OSW tend to focus on the biological, technical, and environmental feasibility (Abhinav et al., 2020;Buck & Langan, 2017;van den Burg et al., 2020;Weiss et al., 2018b). Studies have concluded that co-located offshore aquaculture of low-trophic species is possible but dependent on environmental conditions and location due to factors such as variability in growth rates, survival, and nutrient availability Buer et al., 2020;Kotta et al., 2020;van den Burg et al., 2020;Kotta et al., 2022;Maar et al., 2023). ...
... De esta manera, una revisión exploratoria de la literatura mostró que su enfoque principal está en la reutilización de los residuos o desechos y su articulación en la creación de productos cada vez más accesibles y asequibles para todos los sectores de la sociedad, [38]- [40] aunque se reconocen y abordan contradicciones y barreras en la operacionalización de estas nociones básicas. [41]- [43]. ...
Resumen- El interés por el cumplimiento de los Objetivos del desarrollo sostenible ha crecido recientemente, hecho refrendado por el volumen de recursos e iniciativas encaminados a la solución de los problemas trascendentes de la humanidad. Una de las construcciones conceptuales empleadas para sustentar teórica y metodológicamente estas iniciativas es la llamada Economía Azul, un enfoque basado en la unidad entre sostenibilidad y protección de los océanos y mares. Sin embargo, se aprecia un desprendimiento del enfoque principal y una marcada deriva economicista, por lo que la investigación estuvo dirigida a analizar la producción científica sobre Economía Azul en la base de datos SCOPUS durante el período 2014 – 2024, como base para identificar las principales líneas temáticas y profundizar en su relación con el desarrollo sostenible. El estudio se sustentó en un enfoque mixto, secuencial e integrativo, basado en un protocolo compuesto por dos fases principales y un énfasis en la triangulación sistemática para la integración final de los datos. Los principales hallazgos apuntan hacia un campo en consolidación, mayor presencia y visibilidad de países desarrollados en la producción científica, la necesidad de desarrollar una mejor comprensión sobre la Economía Azul y la prioridad de estudios críticos y, al menos, multidisciplinares. En sentido general, los hallazgos permiten concluir que la Economía Azul representa un enfoque con alcance paradigmático, donde confluyen diversas propuestas teórico-prácticas y que, si bien es preciso desarrollar modelos comprensivos para su implementación, esta representa un amplio abanico de oportunidades para la solución de problemas medioambientales, sociales y económicos.
... By sharing infrastructure and spatial planning, MPPs can reduce costs and enhance economic efficiency. This economic synergy is essential for the sustainable growth of the Blue Economy [84]. ...
Floating Solar Projects (FSP) offer a revolutionary approach to harnessing solar energy, with the potential to address land-use constraints and tap into the expansive resources both on land and ocean surfaces. This paper conducts a comparative analysis of land-based and ocean-based Floating Solar PhotoVoltaic (FSPV) deployments using SWOT (Strengths, Weaknesses, Opportunities, and Threats), TOWS (a strategic approach based on SWOT), and PESTLE (Political, Economic, Social, Technological, Legal, and Environmental) analysis. We identify the unique strengths and weaknesses of each approach, such as land-based FSP’s easier implementation versus ocean-based FSP’s potential for large-scale generation. The TOWS matrix further develops strategic options for leveraging these differences, while the PESTLE analysis assesses the political, economic, social, technological, legal, and environmental factors that will shape the success of each deployment. Additionally, the analysis highlights the abundance of opportunities for FSPV systems, particularly in terms of policy and economic support, contributions to Sustainable Development Goals (SDGs), and technological advancements. This comprehensive assessment provides critical insights for stakeholders aiming to implement FSPV strategically, driving the transition toward a sustainable energy future.
... As early as 2011, multi-Purpose Platforms (MPPs) were put forward in some EU-funded "Blue economy" projects as a way to further deepen the understanding of the field and find sustainable, technically and economically feasible solutions for blue economic growth (Abhinaiv, 2022;Commission, 2011Commission, , 2018. ...
ARTICLE INFO Keywords: MultiPurpose platform Aquaculture vessel Hybrid wind-wave energy system Floating offshore wind turbine Single-point turret mooring system Fully-coupled numerical analysis ABSTRACT A fully-coupled aero-hydro-net-mooring time-domain model is constructed by coupling AQWA and FAST with open-source code F2A, initially used for preliminary analysis of a turret-moored deep-sea aquaculture vessel powered by wind energy. Due to wind-wave complementarity at the site, an optimal point absorber is employed to suppress motion around energetic wave periods, particularly near the vessel's heave and pitch natural periods. A framework for detailed analysis of the deep-sea aquaculture vessel with hybrid wind-wave power generation is then established in the time domain, with results compared to preliminary frequency domain findings. Fifteen environmental conditions, including steady and turbulent winds, regular and irregular waves, and extreme scenarios representing 50-and 100-year return periods in the Northern Bohai Sea, are considered. The study verifies the rationality of the internal turret mooring system and the point absorber, providing detailed guidance for mooring design by analyzing mooring dynamics. This research focuses on deep-sea aquaculture vessels and hybrid wind-wave energy systems, emphasizing the complex coupling effects between them.
... In the framework of ocean area exploitation, a novel technology now being researched is multipurpose platforms (Abhinav et al., 2020). A multipurpose platform is a floating platform hosting different technologies for contemporary energy and food production. ...
In the field of floating wind energy, large-scale wind turbine models deployed in natural environments represent a key link between small-scale laboratory tests and full-scale prototypes. While implying smaller cost, design and installation effort than a full-scale prototype, large-scale models are technologically very similar to prototypes, can be tested in natural sea and wind conditions, and reduce by a consistent amount the dimensional scaling issues arising in small-scale experiments. In this framework the presented work report the aerodynamic and control system assessment of a 1:15 model of the DTU 10 MW wind turbine installed on a multipurpose-platform model for fish farming and energy production. The model has operated for 6 months in a natural laboratory and has been exposed to fully natural and uncontrolled environmental conditions. Assessment is performed in terms of rotor thrust force and power controller parameters such as rotor speed, blade pitch and rotor power as a function of incoming wind speed.
... Multi-purpose platforms (MPP) could be a solution in practice. Achieving synergies through MPP, which build offshore platforms that serve the needs of multiple offshore industries, such as energy and aquaculture, and manage the tensions arising from their coexistence (Abhinav et al., 2020). Specifically, the natural resource administrative authorities shall, through the marine spatial detailed planning, assess in advance the types of marine activities that have synergies with the dominant functions of the sea area, and give priority to the granting of sea area use right for such sea use activities. ...
As China’s marine economy continues to flourish, the scarcity of offshore marine space has become increasingly apparent. The establishment of multi-tiered sea use right in 2023 represents an effective solution to facilitate the scientific allocation and effective protection of marine resources, thereby promoting high-quality development of marine economy. This paper offers a comprehensive and analytical overview of China’s multi-tiered sea use right reform in the context of current status of ocean multi-use research and practice worldwide. China’s multi-tiered sea use is an innovative practice of ocean multi-use in western countries. This paper adopts the methods of literature analysis, normative analysis, empirical analysis and case study. On the basis of comparative analysis of multi-tiered sea use in China and ocean multi-use in western countries, benefits and challenges of China’s multi-tiered sea use right reform were summarized and analyzed, and suggestions from multiple perspectives are provided for implementing and developing multi-tiered sea use right in China.
... Their lifecycle assessment found that the primary source of pollution occurred during manufacturing of the platform, and the decommissioning costs were affected depending on the recyclability of the platform parts. Abhinav et al. [14] reviewed platforms integrating multiple renewable energy generation sources with co-located aquaculture systems. The study concluded that such systems are still at a low technology readiness level (TRL), with multi-purpose platforms still being far from common practice. ...
The previous research has proven that one of the fundamental requirements for ensuring increased profitability and economic competitiveness in offshore-based projects is co-locating different technologies within the same marine space. This paper presents a number of techno-feasibility analyses for floating offshore technologies for the Maltese Islands, located in the central Mediterranean Sea. The first part compares the feasibility between offshore floating solar photovoltaics with onshore-based systems, taking into consideration Malta’s average land rental price per square metre. The second part considers the use of a novel floating breakwater design that integrates energy storage and creates a sheltered water area for a multi-use marine park, thus introducing different revenue streams. The latter includes renting the sheltered marine space out to operators of floating solar farms, aquaculture cages and vessel berthing facilities, as well as the provision of energy storage services. It is found that the combined income from the multiple revenue streams from the multi-use marine park is still insufficient to justify the investment and that financial support from governments is essential to render the floating breakwaters viable.
... FPV systems are also increasingly being considered for marine applications to address increasing demands among coastal populations for sustainable energy sources, to resolve conflicts over usage of scarce land, and to reduce project costs [6]. FPV infrastructure can also be integrated, or co-located, with offshore applications such as wind energy generation, hydrogen production and aquaculture [68][69][70]. ...
The use of floating photovoltaic systems in freshwater and marine environments is forecast to increase dramatically worldwide within the next decade in response to demands for accelerated decarbonisation of the global economy whilst avoiding competition for land, particularly near population centres. The potential environmental impacts of this expanding, novel technology are gradually becoming apparent and warrant consideration. This study reviews and evaluates the various potential environmental impacts of introducing floating photovoltaic arrays into aquatic (freshwater and marine) ecosystems based on the current state of floating photovoltaic technology and known impacts of similar industries. Environmental impacts of floating photovol-taic systems fall into several categories including shading, impacts on hydrodynamics and water-atmosphere exchange, energy emissions, impacts on benthic communities, and impacts on mobile species. The social acceptability of floating photovoltaic systems and the ability for long-term coexistence with other activities and interests are also discussed. Floating photovoltaic systems have an important role to play in global decarbon-isation, but close collaboration between stakeholders will be required to better understand potential environmental and social impacts of this new technology. Development and validation of appropriate monitoring methods at scale, and consideration of long-term, equitable solutions to identified impacts, is important to enable sustainable expansion of this industry.
... In an effort to meet EU and UN sustainable growth goals, different sectors are combining their technological resources to optimize their logistics, maintenance and exploitation costs. Multi-Use Platforms (MUPs) are defined as platforms designed to explore the synergies of multiple offshore industries (Abhinav et al., 2020;Aryai et al., 2021), such as aquaculture, tourism, transportation, oil production, and marine energy. Several studies and projects have been conducted to combine offshore aquaculture with wind and wave energy (Fig. 1). ...
Due to the increase in world population over the past 30 years, the overall demand for food is expected to increase over the next few decades. To meet the additional demand for food, the world will need to increase global food production by 70% by 2050. In addition, population growth, which will be most noticeable in typically more attractive coastal areas, combined with complex climate change scenarios, will increase pressure on coastal regions. The AquaBreak project emerged as a nature-based offshore solution that simultaneously acts as a breakwater to improve coastal protection and dissipate wave energy, as well as an optimized aquaculture system for food production in countries largely dependent on their local marine economies, such as Portugal and Norway. The AquaBreak Offshore System (AOS) is a modular offshore aquaculture system with a central cage designed to interrupt wave propagation, thus disrupting the natural propagation of waves and serving as a dissipator of wave energy for coastal protection. In the past, many aquaculture and offshore metallic structures had severe corrosion problems, resulting in an overall shorter life of these structures. The AOS solves the corrosion problem by using environmentally friendly composite materials that are less susceptible to corrosion instead of using only metallic elements, copper, or steel mooring lines. This study examines the implementation of the AOS on the Portuguese coast, with special attention to coastal zones with high erosion rates from Espinho to Caminha. It provides insights into the latest developments of the Aquabreak project and highlights that cost-effective, resilient and eco-friendly synergistic solutions for coastal protection and marine resource exploitation are possible.
... Multi-functional offshore platform is a kind of marine structure that has the functionality to combine offshore platforms, offshore renewables, aquaculture devices and breakwaters (Abhinav et al., 2020). It is known that high construction costs become barriers for many offshore industries, such as offshore renewables and aquaculture. ...
... In particular, vessels used in maintenance operations of offshore wind and solar parks necessitate well-protected areas for safe mooring. Consequently, the transition of the deserted deeper waters into areas developed for multi-purpose use of offshore spaces [10,11], has instigated great interest in the development of floating breakwaters (FBWs) to create sheltered zones [12]. ...
... A numerical modelling study of ecosystem behaviour shows that adverse impacts on fishing activities can be mitigated by an increase (up to 7%) in catches in proximity to wind farms due to the influx of fish near the structures and by slight modifications in the make-up of these catches. The creation of multi-purpose platforms, which would notably integrate aquaculture into offshore turbine foundations, is another approach currently being studied that aims to foster cohabitation of different activities in the project area [93]- [95]. ...
link to full-text: https://nergica.com/en/offshore-wind-power-in-canada/
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Given Canada’s objective of achieving net-zero emissions by 2050, it is important to carefully explore all clean energy generation options in order meet the country’s corresponding energy needs. Indeed, in order to become carbon neutral, Canada would need to install 150 GW of wind power capacity, as compared to the current figure of just 14.3 GW. To rise to this challenge, it is therefore important to explore various options such as offshore wind, which has been adopted by a large number of countries around the globe.
At the present time, Canada does not operate any offshore wind projects, despite having substantial wind regimes along its Atlantic and Pacific coasts, not to mention the Great Lakes. Canada’s Atlantic seaboard in particular has one of the best wind potentials in the world. Additionally, Canada already boasts a robust wind industry as well as associations and an experienced labour force capable of developing offshore wind power projects.
In this paper, experts address the various aspects of offshore wind: technical, technological, regulatory, etc. They also provide a general overview of the situation in Canada.
Quick recap of the report’s recommendations:
The development of offshore wind projects in Canada must take into account a multitude of factors, notably regulatory frameworks, subsidies and financial incentives, environmental authorization and land planning, stakeholder involvement, environmental impact assessments and international collaboration. In this regard, it is notably recommended to:
-Clearly define regulatory requirements for offshore wind projects;
-Promote active collaboration between international partners of the offshore wind industry;
-Encourage and support offshore wind project development in Canada; and
-Intensify research and development.
... Interesting examples of this would be multifunction offshore platforms. They allow optimisation of the use of space and limiting marine environmental impact (Abhinav et al., 2020;Weiss et al., 2020). ...
The paper discusses the current prognoses of aquaculture development worldwide putting an emphasis on its effect on the environment and the issue of the protection of water reservoirs in different countries. Water consumption in diversified aquaculture systems is presented herein as well as the characteristics of the mechanical and biological water treatment methods in fish farms, with particular attention paid to the recirculating water systems. New aquaculture technologies using post-production waters are presented. The paper provides a discussion on the contribution of aquaculture to the global greenhouse gas emissions and the means of limiting this emission. The effect of climate change on aquatic ecosystems is presented in the context of the changes of the aquaculture production profile. The paper includes a brief presentation of the methods of mitigating the changes with respect to contamination of aquatic ecosystems as well as climate change. Reducing the water footprint can be achieved through selective breeding, species diversification and implementation of more technologically advanced aquaculture systems such as: integrated multi-trophic aquaculture, aquaponics and recirculation systems in aquaculture. The need for certification of fish farms with water recirculation systems is justified in the paper. The issues addressed herein are summarised and the main areas for extending the research promoting preservation of aquatic ecosystems in aquaculture are presented.
... Scholars have emphasised the importance of policy coherence, governance frameworks, and stakeholder engagement to ensure the sustainable use of ocean resources. The role of innovation, technology, and finance in supporting the transition to a blue economy has also been highlighted in recent literature (Abhinav et al., 2020). ...
This article overviews the blue economy, its origins, dimensions, and its impact on the global economy. The blue economy is a concept that promotes the sustainable use of ocean resources for economic growth while also preserving the health of marine ecosystems. The chapter discusses the different dimensions of the blue economy, including marine transportation, fisheries, energy, tourism, and biotechnology. It highlights the significant contribution of the blue economy to the world economy, creating jobs, generating wealth, and supporting livelihoods. However, the chapter also highlights the challenges facing the blue economy, such as overfishing, pollution, and climate change, which threaten the health and sustainability of the marine environment. The chapter concludes by calling for greater cooperation and investment in research, innovation, and technology to address these challenges and ensure the long-term sustainability of the blue economy.
... The maritime economy is rapidly expanding, with much attention recently paid to traditional and emerging maritime industries through blue economy initiatives (Jentoft et al., 2022). The notion of blue growth recognises maritime economic activities as crucial drivers for maximising economic growth and employment and constitutes a strategy to ensure the long-term environmental sustainability of marine sectors (Abhinav et al., 2020;Burgess et al., 2018;Eikeset et al., 2018). The European Union (EU), for instance, proposed blue growth as a strategy to steer the EU out of the global financial crisis of 2008 by opening Europe's oceans, seas, and coastal areas for job creation and economic growth (European Commission, 2012). ...
The blue economy concept has drawn global attention to the maritime economy, recognising expanding maritime industries such as shipping as crucial drivers of economic growth. In recent decades, seaports have correspondingly witnessed significant expansion, allowing them to play a substantial role in achieving blue growth. This study examines the challenges faced by small-scale fishing actors in gaining access to fishing livelihoods in coastal fishing communities close to Ghanaian ports. Drawing on political ecology, the study demonstrates how securitisation in port areas and dispossession has resulted in unstable fishing livelihoods in port communities. The study shows that the growth-oriented goals of port expansions and port security measures have restricted fishing communities’ access to coastal fishing spaces and caused congestion in the canoe bays of Ghana’s fishing harbours. In addition, the urbanisation around the ports has impacted fishers’ ability to meet the rising cost of living in fishing communities with fishing incomes. Furthermore, the study discusses how the new Jamestown fishing harbour complex project has displaced small-scale fishing actors and become a site of contestation between a coastal fishing community and local government authorities. In conclusion, as coastal fishing actors lose their only source of livelihood, resistance may escalate into different forms of maritime conflicts in the blue economy. The study recommends addressing the marginalisation and exclusion of traditional coastal fishing livelihoods to ensure a more equitable blue economy.
... This study suggested there was no negative impacts of operating wind turbines observed on the growth of these species. Although there have been concepts, models, protocols, and social-economic assessments on the co-location of OWF and mariculture for more sustainable usage of marine space [23][24][25][26][27][28], there is scant information about field research on the impacts of operating offshore wind turbines on mariculture. Even this study was conducted in natural sites with complex environmental factors, it still provides valuable information for future mariculture and OWF development. ...
... Multi-functional offshore platform is a kind of marine structure that has the functionality to combine offshore platforms, offshore renewables, aquaculture devices and breakwaters (Abhinav et al., 2020). It is known that high construction costs become barriers for many offshore industries, such as offshore renewables and aquaculture. ...
... Co-location and multiuse platforms or floating artificial islands, where marine aquaculture is combined with other activities such as offshore energy production, are sometimes suggested as a way of reducing conflict, sharing resources and optimising use of space. [225][226][227][228] In multiuse platforms, activities are integrated within the same structure(s), whereas co-location as a broader concept can involve multiple activities sharing the same space (and infrastructure such as shared electricity) without being physically connected to each other. 229 Sharing space and resources is considered by some to be a way of increasing social licence to operate. 100 219 reported that fishery representatives saw co-location as a risk and were sceptical of any advantages, so a long-term and continuous process of engagement amongst all stakeholders would be required to address concerns. ...
Marine aquaculture has the potential to increase its contribution to the global food system and provide valuable ecosystem services, but appropriate planning, licensing and regulation systems must be in place to enable sustainable development. At present, approaches vary considerably throughout the world, and several national and regional investigations have highlighted the need for reforms if marine aquaculture is to fulfil its potential. This article aims to map and evaluate the challenges of planning and licensing for growth of sustainable marine aquaculture. Despite the range of species, production systems and circumstances, this study found a number of common themes in the literature; complicated and fragmented approaches to planning and licensing, property rights and the licence to operate, competition for space and marine spatial planning, emerging species and diversifying marine aquaculture production (seaweed production, Integrated Multi-Trophic Aquaculture [IMTA], nutrient and carbon offsetting with aquaculture, offshore aquaculture and co-location and multiuse platforms), and the need to address knowledge gaps and use of decision-support tools. Planning and licensing can be highly complicated, so the UK is used as a case study to show more detailed examples that highlight the range of challenges and uncertainty that industry, regulators and policymakers face across interacting jurisdictions. There are many complexities, but this study shows that many countries have undergone, or are undergoing, similar challenges, suggesting that lessons can be learned by sharing knowledge and experiences, even across different species and production systems, rather than having a more insular focus.
... Although our model identifies the socioeconomic opportunity to deploy MU, the existing projects addressed in European seas mainly supported by public funds and subsidies, showing the novelty of such MU platforms [24,92]. For example, The MERMAID project explored the possibility of using innovative multi-purpose platforms for combining aquaculture with offshore wind and wave production [86,93]. ...
The rapid development of offshore wind farms (OWFs) has raised concerns about the increasing conflicts and synergies with existing marine activities, especially the traditional fishery industry, from socioeconomic and environmental perspectives. Quantifying the conflicts and synergies require frameworks that can consider environment and economic systems simultaneously. This study builds on and extends a well-established computable general equilibrium (CGE) model to incorporate a natural capital and ecosystem service into the modelling framework, enabling a comprehensive analysis of the two-way interactions between the economy and natural environment. Our results suggest that expansion of OWFs has significant negative impacts on the seafood sectors, whereas fish stocks benefit slightly as fewer fish are harvested. Moreover, the increase in fish stocks due to the closed areas and artificial reef effect could bring benefits to the fishing sector, and pass onto the wider economy. The combined impacts of expansion of OWFs and increased fish stock demonstrate the potential benefits of multi-use of marine spaces by the OWFs and fishing activities. This modelling approach provides an illustration of the potential and importance of incorporating natural capital into CGE models in practice, which could be used for policy making regarding marine renewable energy and sustainable development planning in the marine environment.
... The power network-management is established grounded on the size of MPP and interconnection category such as grid-connected or isolated. In [114], different number of MPP schemes are studied, targeting to assign the multidisciplinary feasibility tasks. In [115], a complete assessment of Blue-Growth and MPP are studied; both techniques are studied in strategy plans as along with the comprehensive range of current knowledge being analyzed. ...
Renewable energy resources such as offshore wind and wave energy are environment friendly and omnipresent. A hybrid offshore wind-wave energy (HOWWE) system produces a more efficient, economical and sustainable form of energy than exploitation of the individual resources. The objective of this paper is to give a detailed review of co-generation technologies for HOWWE. The proposed areas of this review paper are arranged based on the power conversion techniques, response coupling, control schemes for co-generation and complimentary generation, colocation and the integrated conversion system. This paper aims to offer a systematic review to fully cover recent research and development of the HOWWE system. The current HOWWE structures lack efficiency due to their design and AC-DC-AC power conversion that need to be improved by applying an advanced control strategy. Thus, using different power conversion techniques and control system methodologies, the HOWWE system can be improved and transferrable to the other hybrid models such as hybrid solar and wind energy. The state-of-the-art HOWWE systems are reviewed. Critical analysis of each method is performed to evaluate the best possible combination for development of a HOWWE system.
Production sustainable energy is one of the crucial issues in all countries. In this sense, marine renewable energies (MREs) can play a prominent role for the sustainable development of societies due to its abundant and sustainable characteristics. On the other hand, different sustainability limitations and less research have restricted their rapid commercialization. This study aims to identify the important indicators influencing sustainable supply chain of marine renewable technologies, using evidence from different phase of supply chain in MREs. Offshore wind, waves, tidal range, tidal currents, ocean currents, ocean thermal energy conversion, and salinity gradients are the main branches of MREs technologies, and they are related to the sustainability criteria: technical, economic, social, and environmental. From the 345 indicators generated from literature, 33 different indicators are considered relevant in with those four criteria of sustainability in four sections of supply chain (sourcing, delivery and distribution, consumption, and recycling part) using Fuzzy Delphi method. The results of the Fuzzy Delphi process showed that marine energy production to the local environment, facility cost of energy production, and consumption of energy are of highest importance. So, this research serves as a valuable guide for policymakers, industry stakeholders, and researchers aiming to enhance the sustainability and viability of marine renewable energy supply chains.
As global demand for sustainable biomass and need to mitigate global warming begin to rise, cultivation of seaweed has gained significant attention in recent years due to its potential for carbon recycling. However, limited availability of suitable coastal areas for large-scale seaweed cultivation has led to exploration of offshore environments as a viable alternative. The nature of many offshore environments often exposes seaweed farming systems to harsh environmental conditions, including strong waves, currents, and wind. These factors can lead to structural failures, kelp losses, and significant financial losses for seaweed farmers. The main objective of this study is to present a robust design and numerical analysis of an economically viable floating offshore kelp farm facility, and evaluate its stability and mooring system performance. A numerical method of preliminary designs of the offshore aquaculture systems were developed using the OrcaFlex software. The models were subjected to a series of dynamic environmental loading scenarios representing extreme events. These simulations aimed to forecast the overall dynamic response of an offshore kelp farm at a depth of 50m and to determine the best possible farm design with structural integrity for a selected offshore environment. Furthermore, to assess the economic feasibility of establishing offshore seaweed farms, a comprehensive capital expenses analysis was conducted. The results revealed that, in terms of the kelp farms with the same number of the kelp cultivating lines, the cost of building kelp farms will be strongly affected by the cost of mooring lines. The present study may help to understand the dynamic response and economic feasibility of offshore kelp farms.
As global demand for sustainable biomass and need to mitigate global warming begin to rise, cultivation of seaweed has gained significant attention in recent years due to its potential for carbon recycling. However, limited availability of suitable coastal areas for large-scale seaweed cultivation has led to exploration of offshore environments as a viable alternative. The nature of many offshore environments often exposes seaweed farming systems to harsh environmental conditions, including strong waves, currents, and wind. These factors can lead to structural failures, kelp losses, and significant financial losses for seaweed farmers. The main objective of this study is to present a robust design and numerical analysis of an economically viable floating offshore kelp farm facility, and evaluate its stability and mooring system performance. A numerical method of preliminary designs of the offshore aquaculture systems were developed using the OrcaFlex software. The models were subjected to a series of dynamic environmental loading scenarios representing extreme events. These simulations aimed to forecast the overall dynamic response of an offshore kelp farm at a depth of 50m and to determine the best possible farm design with structural integrity for a selected offshore environment. Furthermore, to assess the economic feasibility of establishing offshore seaweed farms, a comprehensive capital expenses analysis was conducted. The results revealed that, in terms of the kelp farms with the same number of the kelp cultivating lines, the cost of building kelp farms will be strongly affected by the cost of mooring lines. The present study may help to understand the dynamic response and economic feasibility of offshore kelp farms. KEYWORDS offshore, mooring systems, kelp cultivation, seaweed farm, dynamical response analysis, economic analysis, capital expenses analysis of offshore seaweed farms Frontiers in Marine Science SC (2024) Engineering design and economic analysis of offshore seaweed farm.
The rapid expansion of offshore wind farms plays a key role in meeting global Net Zero targets by 2050 and if delivered sustainably could address the dual challenges of climate change and biodiversity loss. Many countries are embracing ambitious approaches to environmental impact reduction by implementing concepts such as Biodiversity Net Gain, Nature Positive and No Net Loss. Such policies are now recognized in European and UK
legislation, although generally only applicable to terrestrial activities. For the marine realm, there is little consensus on how Marine Net Gain can provide optimal environmental and societal outcomes from marine activities such as offshore wind farm construction, operation and decommissioning. This study sought to clarify the key issues that need to be addressed for effective implementation of Marine Net Gain. Following recruitment
through a stakeholder mapping exercise, in-workshop and follow-up questionnaires sought to elicit expert opinions from multi-sector UK offshore wind farm stakeholders on a range of aspects of Marine Net Gain policy formulation and delivery. Over 80 % of participants indicated that certain external inputs, including information for climate change adaptation options and habitat mapping data, were important to enable delivery of Marine Net Gain. The most important ecosystem services to include within Net Gain measures were perceived as those relating to fisheries (mean 4.50, SD 0.51), maintaining nursery habitats (mean 4.41, SD 0.59), and climate regulation (mean 4.20, SD 1.). Stakeholders felt the most important Net Gain actions for environmental restoration/
enhancement for future offshore wind deployment were
hellfish/mussel bed (ave rank score 4.06) and
invertebrate habitat restoration (ave rank score 4.60), and actions supporting plankton communities (ave rank
score 4.67). Stakeholders agreed (83 %) that Net Gain actions should be considered at the decommissioning
stage, and the preferred decommissioning option was the complete removal or abandonment of all structures.
Stakeholders felt that strategic Net Gain assessments should prioritize fishing pressures (dredging: mean 4.27, SD
1.03; line and net: mean 4.21, SD 0.89) and those arising from physical structures (mean 4.0, SD 0.85). Aquaculture farming was deemed most feasible to co-exist with fixed offshore wind farms (means 3.93–4.19), while floating wind farms were felt to be more co-locatable with fishing practices (means 3.94–4.06) and carbon
capture storage devices (mean 3.87) compared to fixed structures. Recommendations are suggested for future policy development and scientific research in relation to the application of Marine Net Gain assessment for offshore wind farm projects.
The Sustainable Seas National Science Challenge project—Indigenising the blue economy—focusses on addressing barriers that prevent Māori using their marine resources in a more culturally relevant, economically impactful, and environmentally sustainable manner. During co-development with Māori stakeholders, three key constraints were identified limiting Māori from transitioning to a blue economy. The first is the fragmented regulatory and jurisdictional environment in which Māori operate. The second is the concentration of Māori investment in certain fisheries assets, along with adherence to conventional business models vulnerable to systemic shifts. The third constraint is structural limitations on Māori coastal communities realising economic opportunities in the
marine economy.
This paper combines theoretical sustainable business models and conflict indices in making practical sustainable (i.e., participatory decisions involving economic, social, and environmental features within weak or strong sustainability paradigms) and rational (i.e., informed and consistent decisions within substantive or instrumental rationality) decisions with respect to what , who , where , when , and how to act. The case study, focused on an offshore gas platform, identified when (i.e., the end as opposed to the beginning of extraction activities) and where (i.e., the economic, social, and environmental contexts of the Adriatic Sea in Abruzzo region, Italy). A face‐to‐face questionnaire, submitted to stakeholders, produced the relative weights required by the tested sustainable business models (Lüdeke‐Freund et al., 2018), and it reached a conclusion about how (i.e., in favor of the majority as opposed to average decisions). An application of a linear conflict index (Fasth et al., 2018) highlighted a lack of stakeholders' representativeness and knowledge and solved these issues with a 50% increase of stakeholders involved and an additional discussion with originally invited stakeholders on specific topics, respectively. In summary, the methodology suggested in this paper produced a (strong) sustainable and (substantive) rational decision about what and who based on relative weights expressed by representative and informed stakeholders being engaged at the smallest cost and with the largest support. Thus, the contribution of this paper is twofold: Theoretically, choices among alternative sustainable businesses depend on the adopted sustainability paradigm, and practically, choices among alternative sustainable businesses should be identified according to the adopted sustainability paradigm.
Using mixed methods, this study profiled the key actors of the citrus industry and ascertained the industry’s social and economic needs and contributions in Nueva Vizcaya. Findings revealed that the citrus actors’ work classification is diverse. They comprised plantation owners, farmers and traders who have sufficient years of experience in the industry. The top-most distributed products consist of Satsuma, Ponkan and Szinkom oranges. They distribute the citrus products in the province and in other regions but very few of them export abroad. On social needs, most informants desire to sustain their literacy and training as it is a way to enhance their knowledge and competencies. The distribution of personal protective gears, medicine aids, hospitalization benefit and regular safety inspection make them more secure and safe. Accordingly, the industry has a socializing effect since it offers them and family members employment opportunities and creates in them greater social value in performing their functions. Along economic needs, the key players are optimistic about current public utilities but are still in need of internet service, sanitation for safety purposes, regular waste management, sanitation, environment-friendly and sustainable farming, withholding and filing of their taxes, purchase of health and safety materials, investment on juice processing, fertilizers and pesticides, as well as making accessible the trade centers, creating more spacious trade centers, more fruit stalls and processing centers as these could help sustain the industry. Most participants claimed that the industry has helped them economically in the form of stable incomes, additional source of income, a non-hazardous work environment and health benefits. The identified gaps were varied and multifarious. They emanated from the research participants’ work-related demographics and social and economic needs.
Infestation of wild sea trout with sea lice from marine salmon farms can result in mortality or premature return to freshwater and drive changes in population structure and population regulating effects. Sea trout with varying levels of sea lice infestation have been sampled in Ireland since 1991 and in Scotland since 1997. These sea trout time series are used to express observed sea lice infestation rates (number of lice per gram body mass (n g-1)) at local and national scales in relation to the mortality risk thresholds used to assess potential impacts on wild salmonids from salmon aquaculture in Norway. Analysis of a large international sea trout dataset from Ireland (N = 7,461) and Scotland (N = 16,758) reveals levels of lice infestation on sea trout that imply increased mortality risk in the early years of monitoring in both countries. Lice loads on sea trout have reduced in recent years, likely reflecting improved lice control and changes in salmon farming practice. Population-level increase in risk of mortality or compromised seawater growth or reproduction, inferred from lice infestation rate, was estimated for individual sites. Results reveal that the likely sea trout population regulating effect of sea lice varies among locations; many sites recorded lice levels likely to result in strong regulating effects over a prolonged period, particularly in the west of Ireland. The Norwegian risk assessment framework for marine salmon aquaculture is discussed in relation to the results of lice infestation recorded on sea trout in Ireland and Scotland.
This report was commissioned by SEPA in 2000 to review evidence relating to potential effects of aquacultural nutrients on phytoplankton in Scottish coastal waters
Fish farm operators worldwide are planning to move offshore due to lack of available nearshore production sites in heavily utilized coastal zones, where there is increasing community opposition to coastal development and conflict with other usages such as shipping, fishing, tourism, conservation and recreation. Moreover, offshore sites provide more sea space and generally better water quality, which are needed to increase the production of healthy fish. This review paper begins with the definition of offshore for fish farming based on unified viewpoint and proceeds to highlight the challenges faced by going offshore. Next, the paper presents a review of designs of fish cages from conventional nearshore fish farms to next-generation offshore fish farms, which have to contend with a high energy environment. The fish cages may be divided into the open net cage system and the closed containment tank system. The open net cage system can be categorized further into 5 types. The advantages and disadvantages of the various fish cage designs will be discussed. Further, different types of cage designs are compared with the view to guide feasibility of offshore fish farming. Co-location with other synergetic industries is discussed as a possible example of future offshore fish farms.
Integrating marine renewables and aquaculture is a complex task. The generated power of each renewable technology depends on its source cycle (wind, wave, solar PV), leading to periods of zero power production. On the other side, aquaculture farms require smooth and stable power supply since any power shortage can lead to the loss of the entire farm production. This paper illustrates the sizing of a hybrid energy system (wind,solar PV, energy storage) to power up the aquaculture farm. The sizing is based on available commercial technology and the system is mounted on a single multi-purpose platform. Reliability is improved by considering device redundancies. Such hybrid system has not been considered before for aquaculture farms. System rough sizing, based on simple online renewable energy calculators, is used to select existing renewable technologies and HOMER Pro simulation software is used to evaluate the technical and economic feasibility of the microgrid for all possible combinations of the technology selected and perform sensitivity analysis on wind turbine tower height, battery state of charge and solar PV panels reflectance. The optimisation is subject to combined dispatch strategy and net present cost.
The “open ocean” has become a highly contested space as coastal populations and maritime uses soared in abundance and intensity over the last decades. Changing marine utilization patterns represent a considerable challenge to society and governments. Maritime spatial planning has emerged as one tool to manage conflicts between users and achieve societal goals for the use of marine space; however, single-sector management approaches are too often still the norm. The last decades have seen the rise of a new ocean use concept: the joint “multi-use” of ocean space. This paper aims to explain and refine the concept of ocean multi-use of space by reviewing the development and state of the art of multi-use in Europe and presenting a clear definition and a comprehensive typology for existing multi-use combinations. It builds on the connectivity of uses and users in spatial, temporal, provisional, and functional dimensions as the underlying key characteristic of multi-use dimensions. Combinations of these dimensions yield four distinct types of multi-use with little overlap between them. The diversity of types demonstrates that there is no one-size-fits-all management approach, but rather that adaptive management plans are needed, focusing on achieving the highest societal benefit while minimizing conflicts. This work will help to sharpen, refine and advance the public and academic discourse over marine spatial planning by offering a common framework to planners, researchers and users alike, when discussing multi-use and its management implications.
The ECCLR Committee is carrying out this work in advance of the Rural Economy and Connectivity (REC) Committee’s forthcoming inquiry on aquaculture in Scotland, the terms of reference for which will be considered in the coming weeks. The ECCLR Committee’s focus is the report commissioned by SPICe and undertaken by SAMS Research Services Ltd (SRSL). This report contains a review of literature on the environmental impacts of salmon farming in Scotland, the scale of the impacts and approaches to mitigating the impacts. This provides an update of the Scottish Government commissioned report: Review and synthesis of the environmental impacts of aquaculture, published in 2002.
An integrated ecosystem model including fishing and the impact of rising temperatures, relative to species’ thermal ranges, was used to assess the cumulative effect of future climate change and sustainable levels of fishing pressure on selected target species. Historically, important stocks of cod and whiting showed declining trends caused by high fisheries exploitation and strong top-down control by their main predators (grey seals and saithe). In a no-change climate scenario these stocks recovered under sustainable management scenarios due to the cumulative effect of reduced fishing and predation mortalities cascading through the food-web. However, rising temperature jeopardised boreal stenothermal species: causing severe declines in grey seals, cod, herring and haddock, while eurythermal species were not affected. The positive effect of a higher optimum temperature for whiting, in parallel with declines of its predators such as seals and cod, resulted in a strong increase for this stock under rising temperature scenarios, indicating a possible change in the contribution of stocks to the overall catch by the end of the century. These results highlight the importance of including environmental change in the ecosystem approach to achieve sustainable fisheries management.
This study deals with the hydro-aero-mooring coupled dynamic analysis of a new offshore floating renewable energy system, which integrates an offshore floating wind turbine (OFWT), a wave energy converter (WEC) and tidal turbines. The primary objective is to enhance the power production and reduce the platform motions through the combination of the three types of renewable energy systems. Simulation results show that the combined concept achieves a synergy between the floating wind turbine, the wave energy converter and the tidal turbines. Compared with a single floating wind turbine, the combined concept undertakes reduced surge and pitch motions. The overall power production increases by approximately 22%–45% depending on the environmental conditions. Moreover, the power production of the wind turbine is more stable due to the reduced platform motions and the combined concept is less sensitive to the transient effect induced by an emergency shutdown of the wind turbine.
Cumulative effects assessments (CEAs) are inherently complex and seldom linked to real-world management processes • A risk-based CEA contains risk identification , risk analysis and risk evaluation, revealing the risk of exceeding thresholds • Embedding CEAs in a risk management process reduces complexity, streamlines scientific products, and increases transparency • CEAs can be supported in practice by standardized terminology, procedures and the recent development of integra-tive methods Marine ecosystems are increasingly threatened by the cumulative effects of multiple human pressures. Cumulative effect assessments (CEAs) are needed to inform environmental policy and guide ecosystem-based management. Yet, CEAs are inherently complex and seldom linked to real-world management processes. Therefore we propose entrenching CEAs in a risk management process, comprising the steps of risk identification, risk analysis and risk evaluation. We provide guidance to operationalize a risk-based approach to CEAs by describing for each step guiding principles and desired outcomes, scientific challenges and practical solutions. We reviewed the treatment of uncertainty in CEAs and the contribution of different tools and data sources to the implementation of a risk based approach to CEAs. We show that a risk-based approach to CEAs decreases complexity, allows for the transparent treatment of uncertainty and streamlines the uptake of scientific outcomes into the science-policy interface. Hence, its adoption can help bridging the gap between science and decision-making in ecosystem-based management.
Proponents of marine renewable energy worldwide highlight that regulatory and consenting procedures are a significant barrier to the upscaling of infrastructure required to transform the energy generation sector. Uncertainties about the cumulative effects of marine renewable energy developments cause substantial delays during the consenting process, which are exacerbated by the lack of clarity about how to assess cumulative effects. These obstacles have contributed to perceptions that this essential emerging industry receives disproportionate scrutiny relative to established maritime activities. However, alongside legislated targets to reduce carbon emissions, there are legal obligations to protect, maintain and improve the condition of the marine environment. As the imperative to halt the decline in the condition of the environment increases, so expectations of cumulative impact assessments grow and the risk of consenting delays persists. To investigate how robust current cumulative impact assessment practise is, a novel evaluation framework was developed and applied to Environmental Statements of the world's largest offshore wind farms, currently in United Kingdom waters. The framework was designed to evaluate cumulative impact assessments relative to the information needs of decision-makers tasked with managing cumulative effects. We found that current practise does not meet those needs, that there is dissonance between science and practise, and problematic variability between assessments was observed. Straightforward recommendations for improved practise are provided, which if implemented may ease the perceived regulatory burden by clarifying practise. We also highlight additional steps that could enable project-led cumulative impact assessments to better support regional marine management. The results and recommendations will be of interest to countries worldwide where marine renewable energy is emerging alongside ecosystem-approach and marine spatial planning aspirations.
The future growth of maritime activities may be limited due to competition for space as coastal areas become overcrowded. This has led to interest in promoting more efficient and sustainable use of the sea and its resources through the sharing of space. The MARIBE (MARine Investment for the Blue Economy) project investigated the potential of combining marine renewable energy technologies with other emerging industries. The project assessed potential combinations, and identified challenges including the perception of risk due to the combination of new technologies. This work documents the methodology used to assign the risks to various potential combination projects within the blue economy, and applies it to one of the MARIBE case studies: combining wave energy with aquaculture. A standardised methodology of risk assessment was developed comprising three core elements of the risk management process: risk identification, risk analysis and risk mitigation. This method could be applied to each potential project combination, allowing results to be directly comparable, and allowing all stakeholders to have a full understanding of the risks identified. By using a standardised methodology, critical risks could be identified and mitigated, allowing informed decisions to be made on the most suitable combination projects to pursue. The methodology can be applied to other combination projects within these sectors.
An important challenge for conserving and managing marine ecosystems is to advance our understanding of how multiple human stressors, environmental factors and marine resources interact and influence each other. The ecosystems of the Israeli Mediterranean coast have undergone significant ecological changes in recent decades, caused primarily by the introduction of alien species, fishing and the warming of the waters. Here we used a food-web model representing the continental shelf of the Israeli Mediterranean coast to explore the historical dynamics of the area considering the combined effect of alien species, fishing activities and changes in sea surface temperature and primary productivity. The food-web model was fitted to available time series of data from the early 1990s to 2010 using the temporal dynamic module of the Ecopath with Ecosim modeling approach. An important challenge was to model the numerous alien species inhabiting the Eastern Mediterranean Sea, one of the most invaded marine ecosystems of the world. Historical model simulations satisfactorily matched observed data, especially regarding alien groups. However, lack of data from the pelagic environment limited our ability to compare model output with historical observations. Trophic interactions, climate change and fishing were important factors explaining the historical dynamics of the ecosystem, which showed a degradation pattern over time. Results also highlighted an increasing proportion of alien species in biomass and catch over time, with important effects on the food web. This study represents an important step forward in understanding the changes that are occurring in the Israeli continental shelf ecosystem and the Levantine Sea.
Offshore areas are rough and high energy areas. Therefore, offshore constructions are prone to high technical risks. This chapter elaborates on the technical risks of corrosion and biofouling and technical risks through mechanical force. The expected lifetime of an offshore structure is to a great extent determined by the risk of failures through such risks. Corrosion and biofouling threaten the robustness of offshore structures. Detailed and standardized rules for protection against corrosion of offshore structures are currently lacking. There is a need for an accepted uniform specification. A major technical risk of a combined wind-mussel farm is that of a drifting aquaculture construction that strikes a wind turbine foundation. We investigate two scenarios related to this risk: (1) Can a striking aquaculture construction cause a significant damage to the foundation? (2) If a drifting aquaculture construction gets stuck around a turbine foundation and thus increases its surface area, can the foundation handle the extra (drag) forces involved? A preliminary qualitative assessment of these scenarios leads to the conclusion that a drifting mussel or seaweed farm does not pose a serious technical threat to the foundation of a wind farm. Damage to the (anticorrosive) paint of the turbine foundation is possible, but this will not lead to short term structural damage. Long term corrosion and damage risks can be prevented by taking appropriate maintenance and repair actions. Contrarily to mussel or seaweed farms, the impact/threat of a drifting fish farm on structural damage to a wind foundation depends on type, size and the way of construction of the fish cages. The risk of extra drag force due to a stuck aquaculture construction relates particularly to jacket constructions because any stuck construction may lead to (strong) increase of the frontal surface area of the immersed jacket structure and thereby give increased drag forces from currents or waves. To ensure an optimal lifetime and lower operational costs maintenance aspects of materials for both offshore wind and aquaculture constructions should be taken into account already in the design phase of combined infrastructure.
Aquaculture within offshore wind farms has been identified as one of the many possibilities of smart use of marine space, leading to opportunities for innovative entrepreneurship. Offshore areas potentially pose less conflict with co-users than onshore. At the same time, offshore areas and offshore constructions are prone to high technical risks through mechanical force, corrosion, and biofouling. The expected lifetime of an offshore structure is to a great extent determined by the risk of failures. This chapter elaborates on logistical challenges that the offshore industry faces. Operation and maintenance (O&M) activities typically represent a big part of the total costs (e.g. 25–30% of the total lifecycle costs for offshore wind farms). The offshore wind energy sector is considered an industry with promising features for the public and private sector. Large wind farms farther off the coast pose high expectations because of higher average wind speeds and hence greater wind energy yield (in terms of megawatts per capital). These conditions entail additional challenges in logistics, though. One of the main hurdles that hinders use of offshore wind energy is the high cost for O&M. The offshore wind industry will have to solve these problems in order to achieve substantial cost reduction - alone or jointly with other (potential) users. It is precisely the logistical problems around O&M where most likely synergy benefits of multi-use platforms (MUPs) can be achieved. The offshore wind energy industry is eagerly looking for technical innovations. Until now they mostly sought the solutions in their own circles. If the combination of offshore wind energy and offshore aquaculture proves to be feasible and profitable in practice, there may be an additional possibility to reduce the O&M costs by synergy effects of the combined operations. Logistic waiting times, for example, can result in substantial revenue losses, whereas timely spare-parts supply or sufficient repair capacity (technicians) to shorten the logistic delay times are beneficial. A recent study suggests that a cost reduction of 10% is feasible, if the offshore wind and offshore aquaculture sectors are combined in order to coordinate and share O&M together. The presented asset management control model proves useful in testing the innovative, interdisciplinary multi-use concepts, simulating return rates under different assumptions, thus making the approach more concrete and robust.
As we exhaust traditional natural resources upon which we have relied for decades to support economic growth, alternatives that are compatible with a resource conservation ethic, are consistent with efforts to limit greenhouse emissions to combat global climate change, and that support principles of integrated coastal management must be identified. Examples of sectors that are prime candidates for reinvention are electrical generation and seafood production. Once a major force in global economies and a symbol of its culture and character, the fishing industry has experienced major setbacks in the past half-decade. Once bountiful fisheries were decimated by overfishing and destructive fisheries practices that resulted in tremendous biomass of discarded by-catch. Severe restrictions on landings and effort that have been implemented to allow stocks to recover have had tremendous impact on the economy of coastal communities. During the period of decline and stagnation in capture fisheries, global production from aquaculture grew dramatically, and now accounts for 50% of the world’s edible seafood supply. With the convergence of environmental and aesthetic concerns, aquaculture, which was already competing for space with other more established and accepted uses, is having an increasingly difficult time expanding in nearshore waters. Given the constraints on expansion of current methods of production, it is clear that alternative approaches are needed in order for the marine aquaculture sector to make a meaningful contribution to global seafood supply. Farming in offshore marine waters has been identified as one potential option for increasing seafood production and has been a focus of international attention for more than a decade. Though there are technical challenges for farming in the frequently hostile open ocean environment, there is sufficient rationale for pursuing the development of offshore farming. Favorable features of open ocean waters include ample space for expansion, tremendous carrying and assimilative capacity, reduced conflict with many user groups, lower exposure to human sources of pollution, the potential to reduce some of the negative environmental impacts of coastal fish farming (Ryan 2004; Buck 2004; Helsley and Kim 2005; Ward et al. 2006; Langan 2007), and optimal environmental conditions for a wide variety of marine species (Ostrowski and Helsley 2003; Ryan 2004; Howell et al. 2006; Benetti et al. 2006; Langan and Horton 2003). Those features, coupled with advances in farming technology (Fredheim and Langan 2009) would seem to present an excellent opportunity for growth, however, development in offshore waters has been measured. This has been due in large part to the spill over from the opposition to nearshore marine farming and the lack of a regulatory framework for permitting, siting and managing industry development. Without legal access to favorable sites and a “social license” to operate without undue regulatory hardship, it will be difficult for open ocean aquaculture to realize its true potential. Some parallels can be drawn between ocean aquaculture and electricity generation. Continued reliance on traditional methods of production, which for electricity means fossil fuels, is environmentally and economically unsustainable. There is appropriate technology available to both sectors, and most would agree that securing our energy and seafood futures are in the collective national interest. The most advanced and proven renewable sector for ocean power generation is wind turbines, and with substantial offshore wind resources in the, one would think there would be tremendous potential for development of this sector and public support for development. The casual observer might view the ocean as a vast and barren place, with lots of space to put wind turbines and fish farms. However, if we start to map out existing human uses such as shipping lanes, pipelines, cables, LNG terminals, and fishing grounds, and add to that ecological resource areas that require some degree of protection such as whale and turtle migration routes, migratory bird flyways, spawning grounds, and sensitive habitats such as corals, the ocean begins to look like a crowed place. Therefore, when trying to locate new ocean uses, it may be worthwhile to explore possibilities for co-location of facilities, in this case wind turbines and fish and shellfish farms. While some might argue that trying to co-locate two activities that are individually controversial would be a permitting nightmare, general agreement can probably be reached that there are benefits to be gained by reducing the overall footprint of human uses in the ocean. Meeting the challenges of multi-use facilities in the open ocean will require careful analysis and planning; however, the opportunity to co-locate sustainable seafood and renewable energy production facilities is intriguing, the concept is consistent with the goals of Marine Spatial Planning and ecosystem based management, and therefore worthy of pursuit.
As we exhaust traditional natural resources upon which we have relied for decades to support economic growth, alternatives that are compatible with a resource conservation ethic, are consistent with efforts to limit greenhouse emissions to combat global climate change, and that support principles of integrated coastal management must be identified. Examples of sectors that are prime candidates for reinvention are electrical generation and seafood production. Once a major force in global economies and a symbol of its culture and character, the fishing industry has experienced major setbacks in the past half-decade. Once bountiful fisheries were decimated by overfishing and destructive fisheries practices that resulted in tremendous biomass of discarded by-catch. Severe restrictions on landings and effort that have been implemented to allow stocks to recover have had tremendous impact on the economy of coastal communities. During the period of decline and stagnation in capture fisheries, global production from aquaculture grew dramatically, and now accounts for 50% of the world’s edible seafood supply. With the convergence of environmental and aesthetic concerns, aquaculture, which was already competing for space with other more established and accepted uses, is having an increasingly difficult time expanding in nearshore waters. Given the constraints on expansion of current methods of production, it is clear that alternative approaches are needed in order for the marine aquaculture sector to make a meaningful contribution to global seafood supply. Farming in offshore marine waters has been identified as one potential option for increasing seafood production and has been a focus of international attention for more than a decade. Though there are technical challenges for farming in the frequently hostile open ocean environment, there is sufficient rationale for pursuing the development of offshore farming. Favorable features of open ocean waters include ample space for expansion, tremendous carrying and assimilative capacity, reduced conflict with many user groups, lower exposure to human sources of pollution, the potential to reduce some of the negative environmental impacts of coastal fish farming (Ryan 2004; Buck 2004; Helsley and Kim 2005; Ward et al. 2006; Langan 2007), and optimal environmental conditions for a wide variety of marine species (Ostrowski and Helsley 2003; Ryan 2004; Howell et al. 2006; Benetti et al. 2006; Langan and Horton 2003). Those features, coupled with advances in farming technology (Fredheim and Langan 2009) would seem to present an excellent opportunity for growth, however, development in offshore waters has been measured. This has been due in large part to the spill over from the opposition to nearshore marine farming and the lack of a regulatory framework for permitting, siting and managing industry development. Without legal access to favorable sites and a “social license” to operate without undue regulatory hardship, it will be difficult for open ocean aquaculture to realize its true potential. Some parallels can be drawn between ocean aquaculture and electricity generation. Continued reliance on traditional methods of production, which for electricity means fossil fuels, is environmentally and economically unsustainable. There is appropriate technology available to both sectors, and most would agree that securing our energy and seafood futures are in the collective national interest. The most advanced and proven renewable sector for ocean power generation is wind turbines, and with substantial offshore wind resources in the, one would think there would be tremendous potential for development of this sector and public support for development. The casual observer might view the ocean as a vast and barren place, with lots of space to put wind turbines and fish farms. However, if we start to map out existing human uses such as shipping lanes, pipelines, cables, LNG terminals, and fishing grounds, and add to that ecological resource areas that require some degree of protection such as whale and turtle migration routes, migratory bird flyways, spawning grounds, and sensitive habitats such as corals, the ocean begins to look like a crowed place. Therefore, when trying to locate new ocean uses, it may be worthwhile to explore possibilities for co-location of facilities, in this case wind turbines and fish and shellfish farms. While some might argue that trying to co-locate two activities that are individually controversial would be a permitting nightmare, general agreement can probably be reached that there are benefits to be gained by reducing the overall footprint of human uses in the ocean. Meeting the challenges of multi-use facilities in the open ocean will require careful analysis and planning; however, the opportunity to co-locate sustainable seafood and renewable energy production facilities is intriguing, the concept is consistent with the goals of Marine Spatial Planning and ecosystem based management, and therefore worthy of pursuit.
The global population is growing and the demand for food and energy is steadily increasing. Coastal space all over the world becomes increasingly limited and near-shore resources are often already heavily exploited. The use of offshore regions may provide new opportunities, but also involves major challenges such as the development of designs and technologies suitable for offshore condition. The floating TROPOS ‘Green & Blue’ modular multi-use platform concept introduced in this chapter is especially designed for offshore conditions and provides solutions for the problems and obstacles involved in “moving offshore”. The Green & Blue platform concept integrates fish and algae aquaculture with a wind farm. The floating multi-use approach allows for platform operation in deep waters and the promotion of synergies such as joint logistics, shared infrastructure and services, thereby making the use of offshore resources viable and profitable.
Web: https://link.springer.com/book/10.1007/978-3-319-51159-7
Abstract:
Decision-making within the marine realm is a complex process, which endorses ecological, societal and economic needs and they must therefore be managed jointly. Much of the formerly “free oceans” is nowadays subject to intensive uses, thus making the need to optimise the management of the resources within a multifunctional and multi-use(r) context apparent. The high competition for functions and uses of inshore and nearshore waters has given strong incentives to investigate the opportunities of moving industrial activities offshore. The current raise of offshore aquaculture is one prominent example of this. However, our understanding of the social dimensions and effects of offshore aquaculture is yet incomplete. We need to consider also how different multi-use settings for offshore aquaculture affect the socio-economic outcomes on various levels. During the development of offshore aquaculture, this multifunctional perspective has emerged especially for the combination with offshore wind farms. This synergy of two different stakeholders, the so-called multifunctional utilisation of marine areas, can be viewed as a new concept by the implementation of integrated, consensus-based resource planning conditions. We suggest a typology of social dimensions of marine aquaculture, based on the literature of “traditional” nearshore aquaculture. Based on this typology we discuss the current level of knowledge on the socio-economic dimensions of multi-use offshore aquaculture and point to further research needs.
The Mediterranean Sea has been defined “under siege” because of intense pressures from multiple human activities; yet there is still insufficient information on the cumulative impact of these stressors on the ecosystem and its resources. We evaluate how the historical (1950–2011) trends of various ecosystems groups/species have been impacted by changes in primary productivity (PP) combined with fishing pressure. We investigate the whole Mediterranean Sea using a food web modelling approach. Results indicate that both changes in PP and fishing pressure played an important role in driving species dynamics. Yet, PP was the strongest driver upon the Mediterranean Sea ecosystem. This highlights the importance of bottom-up processes in controlling the biological characteristics of the region. We observe a reduction in abundance of important fish species (~34%, including commercial and non-commercial) and top predators (~41%), and increases of the organisms at the bottom of the food web (~23%). Ecological indicators, such as community biomass, trophic levels, catch and diversity indicators, reflect such changes and show overall ecosystem degradation over time. Since climate change and fishing pressure are expected to intensify in the Mediterranean Sea, this study constitutes a baseline reference for stepping forward in assessing the future management of the basin.
Marine aquaculture is expanding into deeper offshore environments in response to growing consumer demand for seafood, improved technology, and limited potential to increase wild fisheries catches. Sustainable development of aquaculture will require quantification and minimization of its impacts on other ocean-based activities and the environment through scientifically informed spatial planning. However, the scientific literature currently provides limited direct guidance for such planning. Here, we employ an ecological lens and synthesize a broad multidisciplinary literature to provide insight into the interactions between offshore aquaculture and the surrounding environment across a spectrum of spatial scales. While important information gaps remain, we find that there is sufficient research for informed decisions about the effects of aquaculture siting to achieve a sustainable offshore aquaculture industry that complements other uses of the marine environment.
Assessing and managing the cumulative impacts of human activities on the environment remains a major challenge to sustainable development. This challenge is highlighted by the worldwide expansion of marine renewable energy developments (MREDs) in areas already subject to multiple activities and climate change. Cumulative effects assessments in theory provide decision makers with adequate information about how the environment will respond to the incremental effects of licensed activities and are a legal requirement in many nations. In practise, however, such assessments are beset by uncertainties resulting in substantial delays during the licensing process that reduce MRED investor confidence and limit progress towards meeting climate change targets. In light of these targets and ambitions to manage the marine environment sustainably, reducing the uncertainty surrounding MRED effects and cumulative effects assessment are timely and vital. This review investigates the origins and evolution of cumulative effects assessment to identify why the multitude of approaches and pertinent research have emerged, and discusses key considerations and challenges relevant to assessing the cumulative effects of MREDs and other activities on ecosystems. The review recommends a shift away from the current reliance on disparate environmental impact assessments and limited strategic environmental assessments, and a move towards establishing a common system of coordinated data and research relative to ecologically meaningful areas, focussed on the needs of decision makers tasked with protecting and conserving marine ecosystems and services.
Offshore wind is proposed as an energy source to upwell nutrient-rich deep water to the ocean photic layers. A spar-buoy wind turbine with a rigid tube about 300 m long is proposed as a pipe to drive deep water up to the surface. The minimum energy required to uplift the water is the potential energy difference between surface waters inside and outside the pipe, which depends on the background density profile. The corresponding surface jump or hydraulic head, h, calculated for several analytical and experimental density profiles, is of the order of 10 cm. If the complete turbine power (of the order of several MW) is used for raising the water (assuming a 100% pump efficiency), in a frictionless flow, very large water volumes, of the order of thousands of m³ s⁻¹, will be transported to the photic layers. In a more realistic case, taking into account pipe friction in wide pipes, of the order of 10 m radius, and a power delivered to the fluid of 1 MW, the volume transport is still very large, about 500 m³ s⁻¹. However, such a large amount of dense water could sink fast to aphotic layers due to vertical static instability (the fountain effect), ruining the enhancement of primary production. Hence, some ways to increase the turbulent entrainment and avoid the fountain effect are proposed. From the energetic viewpoint, artificial upwelling using offshore wind energy is a promising way to fertilize large open sea regions. This mariculture application is, however, severely subjected to atmosphere and ocean climatology, as well as to ecological dynamics. The general problem is multidisciplinary, and some important physical, engineering and ecological questions need to be seriously addressed to improve our confidence in the approach presented here.
Water scarcity is a major problem in many islands. The aim of this paper is to further enhance a pilot technology, which utilizes wind and solar energy to desalinate sea water in order to develop a proof-of-concept design for a fully integrated multi-component and multi-use platform in order to exploit ocean resources in a sustainable way for the production of drinking water and/or electricity under various configurations. The ability of the system to adopt multiple configurations means that it can be tailor made to the specific requirements in different areas. The main idea of the project was to find an economic and ecological solution for the producing drinking water and/or electricity with energy provided by a wind generator and a photovoltaic system, for the water stressed islands of the Aegean by integrating a desalination unit with wind power and photovoltaic panel in the same floating structure. Also, as well as the floating structure is made of steel pipes, it can safely be used as compressed air storage tanks for pressures up to 80 bar. Alternative design combinations of offshore wind turbine together with photovoltaics, desalination unit, compressed air storage and grid connection are presented in order to meet different requirements.
Farmed Atlantic salmon (Salmo salar) escape from net pens and enter rivers to spawn, potentially resulting in genetic introgression and reduced fitness of wild salmon. Here, we quantify genetic introgression of farmed to wild salmon, using molecular genetic markers, in populations from 147 salmon rivers, representing three-quarters of the total wild salmon spawning population in Norway. For 109 rivers with adult modern samples and sample sizes of 20 or more, the average level of farmed genetic introgression was 6.4% (median = 2.3%), with a range between 0.0% and 42.2%. Fifty-one of these rivers showed significant farmed genetic introgression when compared with historical reference samples. We observed a highly significant correlation between estimated farmed introgression and average proportion of escaped farmed salmon. We quantify levels of introgression as unweighted averages or weighted by population sizes, to compare geographical regions and to compare levels of introgression in rivers and fjords designated as locations deserving a high level of protection. We found a generally lower level of introgression in National Salmon Rivers and National Salmon Fjords subjected to formal protection by parliament. We conclude that farmed to wild genetic introgression is high in a large proportion of Norwegian salmon rivers, with the highest levels found in the most intensive areas of salmon farming. The extensive genetic introgression documented here poses a serious challenge to the management of farmed and wild Atlantic salmon in Norway and, in all likelihood, in other regions where farmed-salmon escape events occur with regularity
This paper projects an isolated hybrid model of Offshore wind-diesel-tidal turbine and discusses the stability and reactive power management issue of the whole system. The hybrid system often loses its stability as it becomes prone to uncertain load and input parameters and therefore the necessity of Reactive power management becomes necessary. The overall stability of the hybrid offshore wind-diesel-tidal turbine is made possible by the management of reactive power in the hybrid system through the application of FACTS devices. And therefore the dynamic hybrid model of the DFIG and DDPMSG based offshore wind-diesel-tidal turbine is analysed for stability with different input parameters like wind and tidal energies. For detailed modelling and simulation, a small signal model of the whole hybrid system is designed and reactive power management of the system is achieved by the incorporation of a STATCOM controller. For improvement of stability and reactive power compensation of the hybrid system, GA and PSO optimised STATCOM controller is used.
Microgrid is one practical infrastructure to integrate Distributed Generations (DGs) and local loads. Its optimal operating strategy has aroused great attention in recent years. This paper mainly focuses on the multi-objective optimization of DGs in microgrid by using self-adaptive genetic algorithm (GA) and fuzzy decision. Five objective functions are taken into account comprising voltage offset, transmission loss, construction cost, purchase cost and the environmental cost. In the algorithm, selfadaptation in population size, mutation probability, selection and standardization of objective functions is developed to enhance the speed and efficiency of the algorithm. Moreover, fuzzy decision is applied to determine the final solution. Simulation results show this algorithm can effectively find the optimal solution and improve the real-time control of microgrid, which implies the possibility of potential applications in microgrid energy management system.
The floating wind industry is still in its infancy, with just a few scaled-down prototypes deployed around the world, but at the same time there is a lot of interest in this new field, since it is deemed to play a major role in the future of offshore wind. In the present chapter a classification methodology for floating offshore wind turbine (FOWT) systems is presented, followed by some considerations about their conceptual/preliminary design. In doing so, some of the basic concepts and principles are illustrated, starting from the theories developed for oil and gas offshore floating support structures, but adapting/modifying them specifically for FOWT. Then, the key issues in the design of FOWT are presented, such as the lack of design integration, the need for new and specific guidelines and standards, the limits of the numerical models available and the impact of the floating platform on turbine loading. A case study is then presented, and a look into the future trends that have emerged in the latest years is given.
European seas are encountering an upsurge in competing marine activities and infrastructures. Traditional exploitation such as fisheries, tourism, transportation, and oil production are accompanied by new sustainable economic activities such as offshore windfarms, aquaculture, and tidal and wave energy. One proposed solution to overcome possible competing claims at sea lies in combining these economic activities as part of Multi-Use Platforms at Sea (MUPS). MUPS can be understood as areas at sea, designated for a combination of activities, either completely integrated in a platform or in shared marine space. MUPS can potentially benefit from each other in terms of infrastructure, maintenance, etc. Developing MUPS in the marine environment demands adequate governance. In this article, we investigate four European sites to find out how governance arrangements may facilitate or complicate MUPs. In particular, we apply a framework specifying policy, economic, social, technical, environmental, and legal (PESTEL) factors to explore governance arrangements in four case study sites in different sea basins around Europe (the Mediterranean Sea, the Atlantic Ocean, the North Sea, and the Baltic Sea). The article concludes with policy recommendations on a governance regime for facilitating the development of MUPS in the future.
Following the Blue Growth ambition of the European Commission, the interest in the potential of offshore is growing. This paper aimed to contribute to the discussion on the feasibility of offshore aquaculture development and its potential for multi-use with other maritime activities. A review of national and international projects forms the basis of the paper, where the Dutch North Sea is used as a case-study area. Analysis of technical, economic and ecological boundaries indicated that the potential of fish culture is limited, that seaweed cultivation is likely to gain potential when challenges related to processing will be overcome and that mussel culture has the highest potential in the near future. The North Sea is an area where many stakeholders claim space, which might set boundaries to the number of sites available for mussel culture. Competing claims are a potential source of conflict but may also lead to mutual benefits when smart combinations are sought, e.g. with wind parks, fisheries and nature conservation; especially, the possibility of combining mussel culture in or around wind parks is worthwhile to be further explored. A spatial distribution model adapted for the Dutch North Sea conditions demonstrated that offshore mussel production in wind farms can be profitable. Yet, the commercial interest for offshore development of mussel culture is still limited. Actions required to stimulate further development of the offshore mussel industry are presented for the government, the private sector, research institutes and civil society organizations.
The objective of this study is to assess the environmental and economic performance of a combined wind-wave energy converter over its entire lifecycle. The lifecycle analysis covers embedded costs, energy balance and carbon footprint, right from the raw materials to the final decommissioning. It is demonstrated that Wave Dragon in combination with wind leads to 28% improved LCA figures and lowers its LCOE by 20%. This is due to the fact that wind turbines are a very cost efficient technology when deployed in high wind speed sites if the costs of foundation and grid connection can be kept at a reasonable level – and this is obviously the case when installing on top of a heavy and stable platform like Wave Dragon.
The literature on ocean energy has, to date, largely focussed on technical, environmental, and, increasingly , social and political aspects. Legal and regulatory factors have received far less attention, despite their importance in supporting this new technology and ensuring its sustainable development. Building on the social sciences research agenda developed by the International network for Social Studies of Marine Energy (ISSMER) and published in Energy Policy, a complementary agenda for legal research linked to ocean energy was set out. Key directions for future research structured around the core themes of marine governance: (i) international law; (ii) environmental impacts; (iii) rights and ownership; (iv) consenting processes; and (v) management of marine space and resources were identified.
Over the last 2 decades marine open cage aquaculture in the Mediterranean Sea has grown rapidly, leading to increased productivity in the water column near fish farms. Here we investigated the effect of such increase in productivity on the common bottlenose dolphin Tursiops truncatus. We developed an ecosystem model for the inner Ionian Sea Archipelago, western Greece, to: (1) evaluate the trophic interactions between bottlenose dolphins and their surrounding ecosystem, including cage-associated organisms; (2) investigate simultaneously 3 hypotheses that could explain bottlenose dolphin dynamics: (a) increasing fishing effort and changes in ocean productivity, (b) competition with other species, and (c) increase in number of fish farms; and (3) explore spatial trends in bottlenose dolphins distribution using the increased number of fish farms as an explanatory variable. Comparisons of model predictions with historical time-series data indicate that only the increase in number of cages and thereby in productivity near fish farms contributed to the trends observed in dolphin numbers. Spatial analysis also confirmed an increase in occurrence of these dolphins in the proximity of the farms. These outcomes suggest that high productivity in waters surrounding fish cages—within a coastal area that is markedly oligotrophic—may attract bottlenose dolphins. The present study shows that open cage aquaculture has benefited bottlenose dolphins by easing their way of catching prey. Further studies should be conducted in other areas of the Mediterranean Sea to investigate whether the higher occurrence of bottlenose dolphins around fish cages is a common pattern and if it is driven by the trophic status of the ecosystem or by the type of fishes that surround the cages.
In this study, systems engineering techniques are applied to wave energy to identify and specify stakeholders’ requirements for a commercially successful wave energy farm. The focus is on the continental scale utility market. Lifecycle stages and stakeholders are identified. Stakeholders’ needs across the whole lifecycle of the wave energy farm are analyzed. A list of 33 stakeholder requirements are identified and specified. This list of requirements should serve as components of a technology performance level metric that could be used by investors and funding agencies to make informed decisions when allocating resources. It is hoped that the technology performance level metric will accelerate wave energy conversion technology convergence.
This article studies the feasibility of combining spar-type offshore wind turbine (inspired by Hywind) and a wave energy converter (inspired by Wavestar) by performing numerical simulations in operational conditions. The dynamic responses and power production of wave energy device and wind turbine are investigated for different power-take-off systems. Integrated/coupled aero-hydro-servo-elastic time-domain dynamic simulations considering multi-bodies are applied in this paper. The results show that by choosing proper power-take-off system, it is likely to minimize effects of wave energy convertor on floating wind turbine and hence maintaining the power performance of the wind turbine while getting more power through wave energy device.
The microgrid is a solution to clean and economic power supply for sea islands. This paper presents the hierarchical control design and verification of a multi-mode microgrid on the Zhairuoshan Island in China. This microgrid is designed to operate in both grid-connected mode and islanded mode. A hierarchical-based control strategy is implemented in the microgrid central controller (MGCC). Compared with conventional hierarchical control, the renewable energy generators (REGs) and energy storage system (ESS) are both taken into the design consideration. What's more, a control combined with feedforward and feedback is adopted in the secondary and tertiary control to improve the system performance. The control strategies are verified in the Zhairuoshan Demonstration Microgrid.
In the last decade, multiple studies focusing on national-scale assessments of the ocean wave energy resource in Australia identified the Southern Margin to be one of the most energetic areas worldwide suitable for the extraction of wave energy for electricity production. While several companies have deployed single unit devices, the next phase of development will most likely be the deployment of parks with dozens of units, introducing the risk of conflicts within the marine space.
This paper presents a geo-spatial multi-criteria evaluation approach to identify optimal locations to deploy a wave energy farm while minimizing potential conflicts with other coastal and offshore users. The methodology presented is based around five major criteria: ocean wave climatology, nature of the seabed, distance to key infrastructure, environmental factors and potential conflict with other users such as shipping and fisheries.
A case study is presented for an area off the south-east Australian coast using a total of 18 physical, environmental and socio-economic parameters. The spatial restrictions associated with environmental factors, wave climate, as well as conflict of use, resulted in an overall exclusion of 20% of the study area. Highly suitable areas identified ranged between 11 and 34% of the study area based on scenarios with varying criteria weighting. By spatially comparing different scenarios we identified persistence of a highly suitable area of 700 km2 off the coast of Portland across all model domains investigated. We demonstrate the value of incorporation spatial information at the scale relevant to resource exploitation when examining multiple criteria for optimal site selection of Wave Energy Converters over broad geographic regions.
AcompletehydrodynamicstudyofaMultiUsePlatformdesigned to harvest energy from waves and wind is presented. The steps given in the study, and presented in this paper are: (i) the design of the platform, (ii) the laboratory tests performed at the Cantabria Coastal and Ocean Basin, (iii) the development of a new in-house time domain numerical model that integrates all components and (iv) the first validation cases of the numerical model.
The development of time domain numerical model that coupled the behaviour of the platform and the OWCs based in Cummins equation is presented. The model includes nonlinear friction forces and a quasi-static approach to model the mooring system. The obtained system is extended to include the variation of the pressure inside each chamber. The effect of the wind turbine in the movements and power production of the platform is studied using also a quasi-static approach.
To realistically predict spatial-temporal dynamics of species in marine ecosystems it is essential to consider environmental conditions in conjunction with human activities and food web dynamics. In this study, we used Ecospace, the spatial-temporal dynamic module of Ecopath with Ecosim (EwE) food web model, to drive a spatially explicit marine food web model representing the Southern Catalan Sea (NW Mediterranean) with various environmental drivers and with fishing. We then evaluated the individual and joint effects of environmental conditions and fishing in various compartments of the food web. First we used a previously developed EwE model fitted to time series of data from 1978 to 2010 as a baseline configuration. The model included 40 functional groups and four fishing fleets. We first ran the original Ecospace spatial-temporal dynamic model using the original habitat configuration, in addition to fishing, and we predicted species distributions and abundances. Afterwards, we ran the new habitat foraging capacity model using the most important environmental drivers linked with the Ebro River delta dynamics (salinity, temperature, and primary production), in addition to depth, substrate and fishing, and we compared results with those from the original implementation of Ecospace. Three commercial species, European hake (Merluccius merluccius), anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus), were used to analyse results. Species distributions more closely matched the empirical information available from the study area when using the new habitat capacity model. Results suggested that the historical impacts of fishing and environmental conditions on the biomass and distributions of hake, anchovy and sardine were not additive, but mainly cumulative with a synergistic or antagonistic effect. Fishing had the highest impact on spatial modelling results while the spatial distribution of primary producers and depth followed in importance. This study contributes to the development of more reliable predictions of regional change in marine ecosystems of the Mediterranean Sea.
In this paper, a hybrid wind/solar/fuel cell power plant is designed and a possible power management
strategy is proposed. In particular, wind and solar energy sources are used as primary power suppliers,
while a pure-hydrogen-fueled fuel cell e with hydrogen produced by means of an electrolyzer
recovering excess power e and a battery pack are employed to fulfill the power demand, when the
power supplied by the renewable sources is not sufficient. The analysis is applied to a particular case
study, i.e. the TUNeIT [TUNisia and ITaly] Project, that involves the realization of four artificial islands
to connect Bon (Tunisia) and Pizzolato (Sicily), provided with electrical-power-demanding facilities for
tourists. Components sizing has been performed with HOMER, where a load profile has been assumed
in order to reproduce the possible power demand of one of these artificial islands, while Matlab/
Simulink® is used for simulations and power management strategy design. The obtained results
demonstrate the possibility of realizing an almost self-sustaining renewable power plant, able to
realize a good integration of different energy sources and power converters, with no negative effects
on end-user satisfaction. The system would consist of a wind turbine of 1 MWand a photovoltaic array
of 1.1 MW, acting as primary power sources and several backup systems, such as a 72-kWh battery, a
300-kW fuel cell and a 300-kW diesel engine to cope with power demand unmatches and/or failures.
In order to verify the system performance under different situations, simulation studies have been
carried out using practical load demand profiles and real weather data. Typical winter and summer day
loads have been kept for simulations of a four-season scenario and results are provided to show the
effectiveness of the proposed system. The major drawback encountered during the analysis is the low
value of the utilization factors of both wind turbine and photovoltaic array, which are 10.2% and 15.9%,
respectively. This is obviously due to the low average wind speed and solar irradiation related to
latitude and altitude of the islands and, because of these low utilization factors, despite the presence of
two energy storage systems, the diesel engine must be sometimes turned on to satisfy the power
demand. Nonetheless, the cost-of-energy of 0.522 V/kWh, which includes installing and operating
costs during the entire lifespan of the power plant, seems very promising if justified by the benefit of
very low pollutant emissions.