Search

Over the last two decades, a large body of academic scholarship has been generated on wave and tidal energy related topics. It is therefore important to assess and analyse the research direction and development through horizon scanning processes. To synthesise such large-scale literature, this review adopts a bibliometric method and scrutinises over 8000 wave/tidal energy related documents published during 2003–2021. Overall, 98 countries contributed to the literature, with the top ten mainly developed countries plus China produced nearly two-thirds of the research. A thorough analysis on documents marked the emergence of four broad research themes (dominated by wave energy subjects): (A) resource assessment, site selection, and environmental impacts/benefits; (B) wave energy converters, hybrid systems, and hydrodynamic performance; (C) vibration energy harvesting and piezoelectric nanogenerators; and (D) flow dynamics, tidal turbines, and turbine design. Further, nineteen research sub-clusters, corresponding to broader themes, were identified, highlighting the trending research topics. An interesting observation was a recent shift in research focus from solely evaluating energy resources and ideal sites to integrating wave/tidal energy schemes into wider coastal/estuarine management plans by developing multicriteria decision-making frameworks and promoting novel designs and cost-sharing practices. The method and results presented may provide insights into the evolution of wave/tidal energy science and its multiple research topics, thus helping to inform future management decisions.

In light of climate change and greenhouse gas reduction, countries around the world are doing their part to develop various types of eco-friendly energy. In this context, the Shihwa Tidal Power Plant is an advanced energy generation infrastructure which uses the resources of the sea, a project that pioneers and practices low-carbon, green growth engineering. Not only as an advanced energy generation infrastructure but also it is an eco-friendly infrastructure that resurrected ‘the dead lake’, which had suffered extreme water pollution due to cutoff in seawater circulation after the completion of the tide embankment in 1994. By circulating the water of the lake, new mud flats have appeared in the upstream area, an area once submerged due to the embankment. These new mud flats are providing new shelters for various organisms, thus transforming the lake into an eco-friendly, life-giving one. Most tidal power plants are difficult to construction due to geological features. The Sihwa tidal power plant was developed harmoniously by utilizing the unique geological features and tidal power plant principles on the West coast of the Korean peninsula. Shihwa Tidal Power Plant is a special and differentiated development example of renewable energy production and environmental improvement along with the significant water quality improvement effect of Shihwa Lake due to increased seawater exchange rates. This article therefore presents the review of Shihwa Lake’s environmental issues and eco-friendly energy production process with the aim to identify the good practices, the challenges as well as the lessons learnt from their experience. This development will be another case of a country seeking to develop new marine energy. This is also a good practice of improving the environment of freshwater lakes in coastal areas.

We are motivated to study the exploitation of marine energy as a renewable resource because of society's ever-increasing energy demands, and a concomitant need to reduce greenhouse gas emissions. Additionally, climate-related variations in wave energy should be investigated in order to ensure the stability of its long-term availability. Here, we investigate the potential for wave energy in the Persian Gulf along the southern coasts of Iran. To do so, we have applied the Mike SW numerical model and ECMWF wind field data for a 30-year study, from 1988 to 2017. For this purpose, wave energy was evaluated at six points in the western, northern, southern, and eastern parts of the Persian Gulf. To assess the impacts of climate change, we also consider the wave regime from 2070 to 2099 (for 30 years) following IPCC RCP4.5 and RCP8.5 climate change scenarios. Our findings suggest that in the present climate, seasonal variations in the mean wave parameters (i.e. wave energy, wave period, and significant wave height) correspond to the lowest wave energy in the summers, and highest in the winters. In the future climate change scenarios, energy level variations generally have similar patterns, with slight modulations in some local areas.

Off-grid hybrid power generation systems are widely used in various applications. In particular, RES-based stand-alone power systems can be used to supply offshore load demands, river lighthouses, and other remote applications. The use of RESs has many environmental and economic benefits over other energy sources, especially for the reduction of marine pollution . Solar and wind energies are the most applicable RESs, which are extremely abundant and available at sea. They mainly depend on solar irradiation and wind speed. Therefore, they have many challenges since they are intermittent and unpredictable. In addition, the onboard utilization of PV panels and WT have been investigated from various technical, economic, and management aspects to obtain the maximum power on the limited space ofthe ship.

Regarding the interest in renewable energies, several sources of energy production have been studied and still under improvement. In this work, we are interested in harnessing marine energy currents exploiting the hydrokinetic turbines. The purpose of this study is to provide a comprehensive assessment of the hydrodynamic loads of a 3-blade horizontal-axis marine turbine using a rotor model adapted to the Moroccan potential. For that, the Blade Element Momentum (BEM) is used to calculate the hydrodynamic loads, to estimate the energetic performance, and to determine the blade optimal parameters for a turbine. In additions, the resulting equations are solved in order to obtain the hydrodynamic loads. For validation, a comparison of pressure coefficients along the chord length was made with the results of the Blade software. The Computations were accomplished for a specific NACA profile. Keywords: Marine current turbine, BEM theory, Hydrokinetic turbine, Hydrodynamics performance

In order to overcome the electricity demand in the country and in its effort to reduce the greenhouse gas emission and climate change, South African (SA) government is encouraging research in the field of renewable energy (RE). Higher educational institutions in each province are involve in different renewable energy projects found by provincial governments and private companies. This paper presents an evaluation of RE potential sources in the province of KwaZulu-Natal (KZN). It is found that KZN province has a RE potential exploitable of about 45 GW divided into 53.63 % of global normal irradiance (GHI), 23.28 % of direct normal irradiance (DNI), 13.52 % of wind energy, 9.51 % of geothermal and 0.06 % of biomass energy that can be converted into electricity, ocean energy and hydropower excluded. With the results exposed in this article, further investigations can be done to determine the net electrical energy that can be produced from those sources for design of RE systems and energy harvesting as well as the appropriate areas to install RE systems. Keywords: Potential energy, Solar energy, Wind energy, Biomass energy, Geothermal energy

A comparison of a tidal turbine's performance and structural loads is conducted using lab-scale numerical models and experimental testing under multiple current-only and wave-current conditions at the IFREMER wave-current flume. Experimental testing, used to validate CFD models, was accomplished using a 0.9 m diameter, 3-bladed tidal turbine and had a blockage ratio of 8% while the turbine was submerged. Initial investigations analysed the performance and loads on the turbine under uniform and profiled current-only conditions. The presence of a profiled velocity gradient was found to have a negligible effect on the average performance characteristics; however, transient thrust, torque and out of plane bending moment loads experienced much greater variations. These load fluctuations were further increased with increasing levels of shear in the velocity profile, while peaks in the turbine loads coincided with its rotational frequency. The addition of regular, Stokes 2nd Order Theory waves added to the complexity of the flow conditions experienced by the turbine. The effect on the average performance characteristics were negligible while the total turbine thrust and torque fluctuations increased by 35 times that of the current-only cases. Peaks in the loads aligned with the wave surface elevation, indicating the importance of transient analyses of dynamic loads.

Airborne wind energy systems convert wind energy into electricity using tethered flying devices, typically flexible kites or aircraft. Replacing the tower and foundation of conventional wind turbines can substantially reduce the material use and, consequently, the cost of energy, while providing access to wind at higher altitudes. Because the flight operation of tethered devices can be adjusted to a varying wind resource, the energy availability increases in comparison to conventional wind turbines. Ultimately, this represents a rich topic for the study of real-time optimal control strategies that must function robustly in a spatiotemporally varying environment. With all of the opportunities that airborne wind energy systems bring, however, there are also a host of challenges, particularly those relating to robustness in extreme operating conditions and launching/landing the system (especially in the absence of wind). Thus, airborne wind energy systems can be viewed as a control system designer's paradise or nightmare, depending on one's perspective. This survey article explores insights from the development and experimental deployment of control systems for airborne wind energy platforms over approximately the past two decades, highlighting both the optimal control approaches that have been used to extract the maximal amount of power from tethered systems and the robust modal control approaches that have been used to achieve reliable launch, landing, and extreme wind operation. This survey will detail several of the many prototypes that have been deployed over the last decade and will discuss future directions of airborne wind energy technology as well as its nascent adoption in other domains, such as ocean energy., Annual reviews in control, 52, ISSN:1367-5788

Marine energy is a major source of renewable energy and yet remains untapped. As the ocean covers about two-thirds of the Earth’s surface, it contains a large amount of energy. Energy can be extracted from the sea exploiting several phenomena, such as salinity gradient (energy from the difference in the salt concentration between seawater and fresh water), temperature gradient, waves, and ocean currents. Among these, ocean waves have tremendous potential as a source of renewable energy. The vast amount of of energy from the waves could meet an important part of the energy demand for humankind. Wave energy is enormous, reliable, and has higher energy density compared to wind power and solar power, and thus offers a good correlation between resource and demand. Waves also offer multiple locations for energy harvesting from the shoreline to deep water. There has been worldwide interest in harnessing this immense power from the ocean that can play a major part to solve our energy problems.

The new blue economy will require new ways of producing, storing, and using energy as technologies and industries move further from shore-based power grids to collect new data sets and use the ocean in new ways. And coastal communities are seeking to integrate renewables to improve energy resilience, reduce carbon emissions, and power clean ports and industries. At the same time, the energy sector is undergoing a revolution toward renewable, distributed technologies that rely on energy storage and smart grid technology. Blue economy and energy technology trends are intersecting creating new challenges and opportunities for cross-sector collaboration. Marine energy (power from waves, tidal currents, ocean currents, and ocean thermal gradients) holds promise as a source of power for the new blue economy. The successful development of marine energy faces many technical, social, and market challenges—as well as access to data and information emerging from the new blue economy. Meeting the full potential of marine energy will require innovation and codevelopment across energy and ocean technology sectors; an improved understanding of ocean physical, biological, and social systems; and new public sector partnerships to coordinate and leverage research and development investments.

Introduction of variable, secured, and intermittent renewable energy resources in the power generation system can be a propitious solution to the worldwide energy crisis. In the context of present situation, involvement of the renewables is undoubtedly a constructive approach to enhance energy security and ensure sustainable energy system. Through incorporation of appropriate strategies, sustained policy support, and institutional settings, renewable energy could be harnessed in a sufficient scale to explicate climatic concerns around the globe. To address this, this article examines Bangladesh’s current state of research in the field of ocean energy particularly tidal energy and investigates future possibilities of development of the technology. Despite large potential for renewable energy sources, currently their contribution to the electricity supply nationwide remains insignificant. This article argues that further significant efforts could be made toward utilizing enormous possibilities of renewables in the coastal zone of Bangladesh thereby developing a national sustainable energy strategy.

America is flush with energy and minerals under and above its continental shelf, but accessing these resources presents environmental risks and requires robust science and regulation to extract and harness them while minimizing harm to the environment. This chapter describes what the Bureau of Ocean Energy Management (BOEM) is, the area it covers, how the bureau is organized, what it does to advance energy and mineral production, what it does to protect the environment in its work, and how science and observational data provided by non-governmental experts and commercial enterprises connect to fulfilling its mission. These factors have direct and indirect impacts on the new blue economy.

Climate change and high energy demand have significantly increased the need for renewable energy sources (RES). Marine and ocean energy sources draw attention through their high energy potential. Offshore wind and marine current energy is an attractive RES with great potential. The wind and current energy in the marine produces an intermittent and unstable power by nature. Energy storage systems are the most effective solution to minimize power fluctuations in the system and to ensure stable energy demand. This paper presents a novel optimal energy management strategy (NOEMS) for optimal power flow control of the offshore wind/marine current/battery/ultracapacitor hybrid power generation system and for the most efficient harvesting of hybrid renewable energy system (HRES). The proposed NOEMS algorithm calculates as real time the amount of power generated by the HRES and demanded by the load. In this study, nine different dynamic operation modes were considered. Experimental results have shown that the battery and ultracapacitor support to the HRES. In this study, the dynamic behavior of the NOEMS algorithm was investigated by performing a sudden load test from 18 W to 30 W. The NOEMS algorithm shows that the system can minimize power loss, voltage fluctuation, control the charge/discharge status of the battery and ultracapacitor. The proposed algorithm continuously shifts the required power over the hybrid energy storage system to provide the load demand continuously. (C) 2020 Elsevier Ltd. All rights reserved.

The increasing popularity of social networks is clearly demonstrated by the huge number of users acquired in a short amount of time. This chapter shows the application of mining social network graphs on the tidal and wave energy system. At the primary level ocean energy systems are assessed through social networks by a further application of clique percolation and SimRank implementation.

Modeling is the first step of the design of any type of energy system and it shows the mathematical relationship between the different parameters. In this chapter first we assess the simulation of tidal and wave energy systems by data analysis. Further analysis of ocean energy system is done with Hadoop and Hive frameworks. At the end of the chapter, page rank algorithm and document clustering are used to assess the different parameters of ocean energy systems.

In recent years a new class of data intensive application has emerged. In these applications data is modeled best not as persistent databases, but rather as transient data streams. In this chapter we assess tidal and wave energy systems through data stream management systems. This chapter includes blocking parameters of tidal and wave energy system and also assesses such types of ocean energy systems by different types of sampling methods. At the end the financial assessment of ocean energy systems is undertaken.

Nowadays big data play an important role in the field of electrical energy systems. An ocean energy system is one part of the electrical energy generation system. In this chapter we discuss ocean energy data assessment through different big data environments. The prefeasibility assessment of an ocean energy system is done through a Hadoop environment, which assesses the site location and primary levels of technical and financial parameters. Energy aware resource allocation and energy aware cluster node management is also done in this chapter. At the end of the chapter an assessment of ocean energy data is done through the NoSQL and MapReduce algorithms.

Clustering is a very important parts of big data analysis, because it is necessary for huge amounts of data to be converted into small subgroups. In this chapter we assess ocean energy systems through clustering approaches and also mention the hierarchy of ocean energy data. This chapter also includes an assessment of ocean energy systems, either tidal or wave, by the partition method and Cure algorithm. Finally, ocean energy clustering data streams are also presented in this chapter.

Frequent item sets play an essential role in many data mining tasks where one tries to find interesting patterns from databases, such as association rules, correlations, and sequences. This chapter includes ocean energy assessment through a market basket model, the development of frequent data set mining of ocean energy systems, as well as fuzzy logic and the Apriori algorithm for the frequent item-set mining of tidal and wave energy systems. Finally, Park Chen Yu and SON algorithms are used to examine data mining of wave and tidal power system parameters.

Ocean energy disinflation and utility tradeoff are the very general parts of the ocean energy system, but ocean energy disinflation also shows that there are some drawbacks of ocean energy systems. In this chapter we discuss the general view of energy disinflation and the utility tradeoff of ocean energy systems. Data privacy of ocean energy system is also presented in this chapter. Further cost assessment of ocean energy systems is done by particle swarm optimization, chaotic particle swarm optimization, and the Big Bang–Big Crunch optimization technique.

Big data refers to the massive datasets that are collected from a variety of data sources for business’ needs to reveal new insights for optimized decision making. The ocean energy system is the modernization of electrical energy generation systems due to the pollution-free nature and the continuous advancement of ocean system technologies. In the ocean energy surroundings, the application of big data analysis-based decision-making and control are mainly in the following three aspects: data stream side management, storage side management, and load side management. The objective of this chapter is to present a technological framework for the management of large volumes and the variety and velocity of related information through big data tools such as NoSQL and Hadoop in order to support the assessment of ocean energy systems. This paper also includes the Market Basket model, an application of the MapReduce algorithm, and also provides light on data stream management and landscape ocean data systems.

Big data is an important part of data analysis, but data mining and process mining are other parts of data analysis, which are utilized to assess the data to find out the relationship between two parameters. In this chapter, first the framework of an ocean energy system through data mining is presented, then a further control system of tidal and wave energy systems through data mining and process mining is discussed. Finally, the difference between data mining and process mining is analyzed.

Wave farms, i.e., arrays of Wave Energy Converters (WECs), have recently been proven to be effective in fulfilling the dual function of carbon-free energy generation and coastal protection. In this paper these dual-function wave farms are referred as dual wave farms. The objective of this work is to investigate the influence of the WEC configuration on the performance of these dual wave farms through a case study: a dual wave farm consisting of WaveCat WECs deployed off an eroding beach. WaveCat is a floating overtopping WEC consisting of two hulls joined by their stern, forming a wedge. Two configurations are considered, with wedge angles of 30° and 60°. To characterize wave-WEC interaction, laboratory tests of a 1:30 WaveCat model are conducted using the two configurations and low-, mid- and high-energy sea states characteristic of the study area. The reflection and transmission coefficients obtained from the laboratory tests are inputted into a suite of numerical models to investigate the hydro- and morphodynamics of the beach. We find that the smaller wedge angle (30°) WECs afford more (less) coastal protection - quantified in terms of dry beach area availability - for short (long) peak periods than WECs with 60 ∘ . These results allow us to conclude that, for optimum performance of dual wave farms, WEC geometry should be adapted dynamically to the sea state.

Energy production based on fossil fuel reserves is largely responsible for carbon emissions, and hence global warming. The planet needs concerted action to reduce fossil fuel usage and to implement carbon mitigation measures. Ocean energy has huge potential, but there are major interdisciplinary problems to be overcome regarding technology, cost reduction, investment, environmental impact, governance, and so forth. This article briefly reviews ocean energy production from offshore wind, tidal stream, ocean current, tidal range, wave, thermal, salinity gradients, and biomass sources. Future areas of research and development are outlined that could make exploitation of the marine renewable energy (MRE) seascape a viable proposition; these areas include energy storage, advanced materials, robotics, and informatics. The article concludes with a sustainability perspective on the MRE seascape encompassing ethics, legislation, the regulatory environment, governance and consenting, economic, social, and environmental constraints. A new generation of engineers is needed with the ingenuity and spirit of adventure to meet the global challenge posed by MRE.

The oceans of the Earth offer impressive amounts of renewable energy, but the technologies to harness the power of the oceans are still at an early stage of their development. This chapter covers major marine energy technologies like energy from ocean streams and tidal range, wave energy, ocean thermal energy, and salinity gradients.

The main forms of renewable energy (RE) used today are biomass energy, hydroelectricity, wind energy, solar energy, and geothermal energy. Although several other RE sources have been extensively discussed, including various forms of ocean energy, these five are likely to still be dominant in 2050. In assessing the probable future of each RE type, it is important to know what factors will tend to enhance or decrease their future output. These include: their energy return on input energy; their technical potential; the impacts that future land use, climate, and other environmental changes will have on their availability; and alternatively, the effects of RE production on the environment.

It is well known that electrical power generation is the key factor for advances in industry, agriculture, technology, and the standard of living. Also, strong power industry with diverse energy sources is very important for a country's independence. In general, electrical energy can be generated from: (1) nonrenewable energy sources such as coal, natural gas, oil, and nuclear; and (2) renewable energy sources such as hydro, biomass, wind, geothermal, solar, and marine power. Today, the main sources for electrical energy generation are: (1) thermal power—primarily using coal and secondarily using natural gas; (2) “large” hydroelectric power plants; and (3) nuclear power. The balance of the energy sources is from using oil, biomass, wind, geothermal and solar, and has visible impact just in a few countries. This chapter presents the current status of electricity generation in the world, various sources of industrial electricity generation, role of nuclear power with a comparison of nuclear energy systems to other energy systems.

The oil and gas sector is not only a major energy producer but also a major consumer of energy. Energy requirements in the form of heat, power, or shaft work during onshore/offshore production, enhanced recovery operation, transportation, processing, and upgrading are mainly provided by fossil-fuel-based conventional technologies. Adaptation of sustainable and eco-friendly renewable energies such as hydropower, photovoltaics, solar thermal energy, wind power, biomass, geothermal energy, and wave power in different industries including the oil and gas sector is now globally examined with some successful stories. Renewable hybridization of the conventional oil and gas sector would reduce energy costs as well as greenhouse gas (GHG) emissions. This chapter investigates recent developments in the integration of renewable energy resources with the oil and gas industry and highlights the prospects.

This contribution outlines and discusses the importance of ocean (marine) energy and its applications for energy production. Various forms of ocean energy are presented and discussed from energy, economic, and environmental points of view. In order to provide a good understanding of the technical presentations of the options for ocean energy, illustrative examples are provided. Furthermore, a set of different case studies are included on analyses of the utilization of ocean thermal energy conversion (a type of ocean energy) for multigeneration incorporating other renewable energy sources (solar and geothermal). In addition, salinity gradient energy (a new type of ocean energy) is also described.

Overview Chapter Energy sustainability is a subject of concern to many nations in the modern world. It is critical for electric power systems to diversify energy supply to include systems with different physical characteristics, such as wind energy, solar energy, electrochemical energy storage, thermal storage, bio-energy systems, geothermal, and ocean energy. Each system has its own range of control variables and targets. To be able to operate such a complex energy system, big-data analytics become critical to achieve the goal of predicting energy supplies and consumption patterns, assessing system operation conditions, and estimating system states—all providing situational awareness to power system operators. This chapter presents data analytics and machine learning-based approaches to enable predictive situational awareness of the power systems.

Growing world population and rapid economic growth are making additional demands on global energy requirement. Carbon dioxide emission has peaked at 32.2 Gt/year and is expected to be at 43 Gt/year by 2016. Such huge emission of carbon dioxide has adverse effect on global climate change. Greenhouse gas emissions of 30% is being generated by the electricity sector followed by 26% from the transportation sector. A huge share of magnetic materials are being used in automotives, transformers, and the power sector, which demands special attention to a new class of magnetic materials. There are two possibilities to reduce deadly air pollution: one is to make energy efficient machines and the other is to explore new green energy sources to provide secure energy supplies. Energy generation focus has also shifted more toward alternative natural resources, such as solar energy, wind energy, bio energy, ocean energy, etc. Use of renewable alternative sources can save money, protect the environment, and ensure clean energy for future generations. Solar energy would yield a never-ending energy supply but the difficulty associated with it is to convert solar energy in an efficient and cost-effective way. The improvement in efficiency of wind turbines demands an increase in height and size that would result in mechanical stresses on the gearbox, blades, and tower.

This chapter highlights the climate change situation and the hydrovision of the African continent. Much emphasis has been laid on the Ghanaian context with the design of a prototype (i.e., the design) of a novel marine energy conversion system that makes use of both wave and ocean current conversion techniques to generate electric power in Ghana. The feasibility of installing this conversion system in the Eastern Coastal Zone of Ghana, as well as its environmental and economic assessments indicates that Ghana possesses the potential, even with regard to the projected impacts of climate change. The coastal geomorphology, seabed topography, and the local met-ocean patterns favor the implementation of this system. The economic appraisal shows that with the appropriate measures, Ghana could offset this endeavor. With the available modern technologies as well as the challenges confronting the national grid, the conversion system is designed to operate off-grid. Pursuing this endeavor is a worthwhile investment in the long term due to the gradual reduction of the electric power deficit in the country, low environmental impacts, potential economic dexterity, and the boundless source of marine energy.

The environmental movements highly emphasize on the use and development of sustainable energy. Most of the renewable energy sources, such as solar, wind, and ocean, are sustainable, i.e., we can utilize them to generate electricity without putting them into danger of getting vanished or depleted from the surface of Earth. Moreover, they are available in bulk quantity in every part of the world, unlike fossil fuel; of which reserves are not available everywhere. Sustainable energy can be defined as a form of energy that can be utilized again and again without putting a source in danger of getting depleted, expired, or vanished. The used and development of clean sustainable energy are widely encouraged as it do not harm our environment and is available all around us free of cost. All renewable sources like ocean, wind, and solar are sustainable energy sources due to the fact that they are stable and available worldwide. The Earth has been blessed with enormous amount of water in the form of oceans or seas. About 70% of Earth is covered with oceans, which is the reason that it seems to be blue from outer space and said to be as “Blue Planet.” Oceans and seas around us have the potential to fulfill all of our current energy demands by providing a clean energy in a bulk quantity; which can be harnessed in number of ways and forms: by exploiting the kinetic energy of waves, the streams of tides and ocean current, and by the temperature gradient present in water. This chapter discusses various methods and technologies introduced to harness this all important form of energy from ocean along with its significance, application, advantages, and disadvantages .

Many countries have significant interests in generating electricity using waves and tidal current technologies. In energetic areas, waves and tidal currents interact for modifying the energy resource and impacting on the design conditions. Changes to the wave climate depend on the strength of the current and the relative wave direction. SWAN simulations of the wave climate around the Orkney Islands, with and without currents, show that considerable changes in the wave climate occur near sites of interest to wave and tidal energy project developers. Using circular statistics the effect of the relative angle between the waves and the current can be investigated. Local effects can lead to 150–200% increases in wave height when the waves oppose the current. These dramatic changes lead to an increase in wave power of over 100 kWm−1. The complex nature of the tides in the channels also leads to large changes in wave power during the so-called slack water period. Wave amplification diagrams are proposed to provide a convenient summary of wave–current effects at a particular site and allow a statistical analysis to be made. When performing resource analysis and site selection work for marine energy projects, wave–current interaction must be considered.

Ploughing of the seabed is needed for the installation of cables and pipelines and is an area of construction likely to increase given plans in the UK and elsewhere for offshore marine energy (wind and tidal). Seabed ploughing is an expensive and sometimes risky operation for which there are limited guidelines as to what the tow force and speed is for an expected trenching profile within a specified ground condition. Most ploughing schemes are designed using semi-empirical approaches, with very few computational tools able to take into account the geometric and material nonlinearity inherited by the ploughing problem. In this paper we describe how the Material Point Method (MPM) is being used as a numerical tool to model seabed ploughing with the aim of providing an improved predictive tool for the future, via an EPSRC-funded research project at Durham and Dundee Universities. Various issues are discussed in the paper including the means of modelling moving essential boundaries and the choice of basis functions, and this new method in MPM is demonstrated on a simple ploughing problem.

This work takes aim at presenting a generic real-time simulation framework for marine power plants with weak power grids, containing transient functionalities such as starting and stopping of arbitrary generators, and phase synchronization. The generator models used in the power plant are hybrid causality models, meaning that they have the ability to switch between causality orientations, between voltage and current. These models facilitate real-time simulations as long as they are solved properly, as will be discussed in this article. Much is devoted to numerical stability, model robustness and power plant control, e.g. rms voltage control, engine speed control, active- and reactive power sharing control and phase synchronization control. Some focus is also given to overall power plant control structure. A case study of a marine power plant including two generators and a fluctuating- and noisy power consumption is presented and analysed, and illustrates the advantages of the proposed framework as well as giving a good foundation for future works. © 2017. This is the authors’ pre-refereed manuscript to the article.

The number of inventions wave energy conversion has created is a remarkable aspect of the topic. Therefore, it is sometimes said that this would be the technological domain in which the largest number of patent applications were numbered (probably more than 3,000 at the current time). According to the website of the European Marine Energy Centre (EMEC), more than 200 wave energy converters were under development in the world in 2017, with varying degrees of maturity.

The potential of electric power generation from marine renewable energies is enormous. Ocean tides and waves are being recognized as a resource to be exploited for the sustainable generation of electrical power. The high load factors resulting from the fluid properties and the predictable resource characteristics make ocean tides and waves particularly attractive for power generation and advantageous when compared with other renewable energies. In this emerging and promising context, this article intends to review and highlight the most recent and challenging ocean energy technologies with a focus on wave and tidal energy converters.

Since the Fukushima nuclear disaster of 2011, Japan has relied on imported fossil fuels for electricity generation, but is quickly increasing its share of renewable energy sources. Recent development has been in biomass, geothermal, wind, and solar PV, though little attention has been given to the potential of marine energy resources. The present paper carries out an analysis of the economic viability of this resource using real wave and tidal current data. The results show that marine energy technologies could be cost-effective at several locations in Japan, and can pragmatically add reliable and predictable power to the energy generation mix. Deployed in straits with strong tidal flows near large population centers in western Japan, SeaGen and Verdant-type tidal turbines are shown to operate at costs far below the current price of electricity in the country. In northern Japan, the Aquabuoy, Pelamis, WaveDragon, and Guarda-type Oscillating Water Column Wave Energy Converters show costs near the current price of electricity. Even though Aquabuoy and Pelamis are now defunct, it is likely that in the future new generation wave energy converters would be able to produce electricity at even lower costs and further enhance the practicality of developing wave power in northern Japan. Keywords Japan; Tidal current; Wave; Cost; Electricity price; Capacity factor Highlights •Tidal current data and wave buoy measurements throughout Japan are utilized. •Energy generated by tidal stream turbines and wave energy converters is calculated. •In heavily populated western Japan, tidal stream turbines are very economical. •In northern Japan, wave energy farms can break even without subsidies. •Developing ocean energy resources reduces emissions and promotes energy independence.

The introduction of a large infrastructure of marine energy technology along coastal environments raises some concern on how this will impact on the marine environment. While there are a number of potential environmental impacts of wave energy devices (eg, collision) the focus of this chapter is on the primary ecological processes that may be influenced by changes in the hydrodynamics as a direct result of the installation of wave energy converters (WECs). These processes include sediment transport, organism transport, pollution, and biogeochemical processes. While full-scale wave energy farms are still in the development phase, the most effective way to predict the environmental impacts of large infrastructure in the coastal marine environment is by coupling ecological with hydrodynamic modelling. This chapter therefore is designed to provide guidance on what factors should be considered when developing a coupled hydrodynamic-ecological model when modelling WEC arrays.

Microgrid and distributed generation (DG), introduces types of DGs commonly used in microgrids.

Due to the high predictability and the high energy density, marine tidal resource has become an area of increasing interest with various academic and industrial projects around the world. In fact, several Marine Current Turbine (MCT) farm projects with multi-megawatt capacity are planned to be installed in the coming years. In this paper, a MCT farm is supposed to be the main energy supply for a stand-alone island. To compensate the MCT farm power variation relating to the tidal phenomenon, an Ocean Compressed Air Energy Storage (OCAES) system is considered to achieve the island power management. The novelty in this work is that conventional Diesel Generators (DGs) would only serve as a backup supply while the main island power supply will be fulfilled by the proposed hybrid MCT/OCAES system. A simplified OCAES model is built-up in this paper with cycle efficiency about 60.6%. Simulations under different working conditions are carried out to validate the feasibility of the hybrid power system. The obtained results show that the proposed system power management can greatly help to decrease DG fossil fuel consumption and CO2 emission.

Recent advances in Energy Storage Devices (ESD) technology has enabled new supervisory control strategies for power generation and distribution on hybrid marine power plants, supported by new class society regulations. A marine hybrid power plant is characterized by the presence of both a traditional power producer, i.e. diesel Generator-set (genset), and an ESD, i.e. batteries. In this paper, two models to estimate strategic loading average fuel consumption were derived and compared. The first model is a higher fidelity dynamic model formulated as a hybrid system, in which the simplified engine dynamics is included, accounting for both continuous-time and discrete-time dynamics representing gensets and ESD as well as the switching. The second model consists of a steady state weighted average, where transient effects are not taken into account. Both models disregard thermal effects on the engine as well as assume that the engine fuel consumption is only a function of the engine speed and power output. The motivation to derive two models is due to the fact that the static model, due to its steady state nature, can estimate the expected weighted average fuel consumption very fast, being a new tool on the hybrid power plant operation optimization. The hybrid model, due to its dynamic nature and accounting for continuous-time and discrete-time dynamics, takes a longer time to simulate the system, which is unfeasible when it comes to real time operations. It is thus required to estimate the errors in the weighted average model due to the simplifications, asserting for which cases it is valid. The results show that the steady state model gives the exact solution in cases where dynamic effects are not relevant. It is a good approximation for systems where the switching period is much higher than the engine time constant, and the load dynamics time constant. The switching frequency is directly related to the ESD energy storage capacity, thus, systems with a large ESD will be better approximated by the steady state model than systems with relatively small ESD. This is a submitted manuscript of an article published by Elsevier Ltd in IFAC-PapersOnLine, 1 November 2016.

Marine meteorology is a subfield of meteorology, which deals with the weather and climate as well as the associated ocean conditions in marine, island, and coastal environments. Marine meteorologists collect and analyze weather and oceanographic data, make marine weather forecasts, and provide marine meteorological services to support marine and coastal activities, including but not limited to shipping, fishing, tourism, offshore oil drilling and mining operations, oil spill control, offshore wind and tidal energy harvesting, search and rescue at sea, and naval operations. The interactions between the atmosphere and the ocean create a unique dynamical framework for the fundamental principles of marine meteorology, and the need for employing air–sea coupled models for marine weather prediction.

The Hardware-In-the-Loop (HIL) simulation is a powerful mean to reduce costs in the design and manufacturing process of an engineering system. HIL techniques allow to use real components inside a simulation of a mathematical model. In this work such techniques are used on the ISWEC wave energy system. ISWEC (Inertial Sea Wave Energy Converter) converts sea waves energy to electric energy by means of the gyroscopic effects produced by a spinning flywheel. The peculiarity of the system lays in the fact that all the moving parts needed to produce energy are sealed inside a hull and therefore protected from the aggressive ocean climate. During the research process on the ISWEC, the gyroscope and the electric generator have been manufactured and mounted on a test rig able to simulate the wave actions on the hull of ISWEC. Those real parts of the system have been replaced inside the full mathematical model of ISWEC. Such HIL system is validated against real wave tank tests carried out at the INSEAN in Rome. The HIL simulations proved to reproduce the real behavior in water waves of ISWEC with errors as small as the 10%.