Tidal power Research Papers - Academia.edu (original) (raw)

2025

This study introduces a comprehensive analysis of offshore wind resource potential in Trinidad and Tobago, leveraging both the Wind Atlas Methodology (WAM) and the numerical wind atlas methodologies to address the region's sparse wind measurement data. Utilizing atmospheric re-analysis data, specifically the ERA5 dataset, in conjunction with the Weather Research and Forecasting (WRF) model, a generalized wind climates (GWCs) for Trinidad and Tobago was generated. These GWCs, refined with topographical and roughness data, guide the siting of offshore wind farms within the Exclusive Economic Zone (EEZ), considering water depths and proximate onshore terrain influences. The study quantifies the economic feasibility of offshore wind through both a levelized cost of electricity (LCOE) analysis and by evaluating the value of redirected natural gas to the petrochemical industry. The LCOE, though currently higher than subsidized domestic electricity rates, is projected to decrease significantly by 2035. Notably, the value of displaced natural gas for petrochemical production offers substantial economic benefits, with potential payback periods for offshore wind investments well under a decade when considering 2021 methanol and ammonia prices. These findings underscore the strategic significance of offshore wind in Trinidad and Tobago's energy mix. By transitioning to renewable energy sources, the nation can mitigate reliance on fossil fuels for power generation while optimizing natural gas usage in high-value sectors.

2025

A B S T R A C T Today, as a rapidly expanding industry within the energy sector, sustainable energy generation through renewable sources such as tidal power creates the potential to get into previously untapped resources. This paper focused on designing, simulating, and analyzing a single rotor tidal turbine and contra-rotating (double rotor) tidal turbine with traditional blade designs and whale-inspired blade designs by using computational analysis. A contra-rotating tidal turbine has a lot of advantages such as near zero reactive torque on the support structure, near-zero swirls in the wake, and high relative inter-rotor rotational speeds. Contra-rotating turbines have capabilities of harvesting higher energy by eliminating the swirling velocity component in the wake as results from the numerical analysis models. Numerical flow visualization proved that the wake verified the reduction of swirl behind the turbine and as expected, the contra-rotating with whale tip blades turbine w...

2025, Marine Policy

Developers have proposed many in-stream tidal projects, but few commercial-scale devices have moved beyond the planning stages to construction and testing. To better understand social impediments to pilot project siting, this comparative case study was conducted in urban Puget Sound, Washington and remote Iguigig, Alaska. Stakeholder interviews were coded to identify themes about project development. Providing local renewable energy, advancing science and technology, and environmental awareness were perceived benefits, while negative environmental impacts, conflicts with other uses, and unintended consequences were perceived concerns of tidal energy. The major themes were: 1) organizations influence siting in urban areas while residents influence siting in rural areas; 2) stakeholder groups cited the wellbeing of their members to justify their stances on in-stream tidal energy projects; and 3) project siting was more successful where there was a simple and uniform assemblage of stakeholders and views. Stakeholders in the smaller, more uniform community were the most supportive of in-stream tidal energy because of a greater need for energy due to fewer energy options. Thus, siting in remote communities could allow tidal energy development to progress in mutually beneficial ways and help states like Washington and Alaska achieve their renewable energy portfolio goals.

2025, Renewable Energy

An accurate assessment of the hydro-environmental impacts of tidal range energy schemes, where the performance of the scheme has an impact on the marine environment and ecology, is crucial in optimising the design and development of such schemes. A proposal for a new coastally-attached impoundment, namely West Somerset Lagoon, has been investigated in this research study and the numerical model TELEMAC-2D has been refined to model the impacts of this scheme on the Bristol Channel and Severn Estuary. Domain decomposition was applied and full momentum conservation between the subdomains was included in the model by implementing momentum source terms at the turbine locations. The results have confirmed the importance of including full momentum conservation in modelling the effects of turbo-machinery in tidal lagoons. It was found that the operation of the scheme decreased the high water level slightly in the Bristol Channel and Severn Estuary, while there was a decrease in the low intertidal areas. The maximum velocity and bed shear stress were predicted to increase in the inner Bristol Channel, while they decreased noticeably across most of the interior of the lagoon, away from the turbine wakes. Furthermore, the operation of the lagoon significantly improved the water renewal in the region.

2025, Water

Understanding the impact of various hydraulic structures, such as coastal reservoirs and tidal range impoundments, has been one of the key challenges of hydro-environmental engineering in recent years. Over the last half-century, several proposals for tidal range schemes in the UK have been scrutinised and then abandoned due to the uncertainty over the environmental footprint and/or the cost of electricity. Therefore, it is essential to understand the fundamental assumptions for reliable hydrodynamic analysis of these projects. This study examined the impact of the fully conserved momentum through tidal structures using a novel approach. The method was applied to 2D and 3D versions of the regional model of Swansea Bay tidal lagoon, examining two different types of velocity distribution at turbine exit. A simplified distribution significantly increased the velocity and length of the jet exiting the turbines during power generation. A realistic distribution gave more accurate results, with jet velocities more closely resembling the situation without including the momentum. The 3D model with realistic distribution has markedly improved the resulting vertical velocity profile. The value of the improved methodology for momentum conservation has proved to be particularly useful in local-scale studies. It can be applied to other similar hydraulic structures and used for the analysis of sediment transport, water quality, etc.

2025, Water

Understanding the impact of various hydraulic structures, such as coastal reservoirs and tidal range impoundments, has been one of the key challenges of hydro–environmental engineering in recent years. Over the last half-century, several proposals for tidal range schemes in the UK have been scrutinised and then abandoned due to the uncertainty over the environmental footprint and/or the cost of electricity. Therefore, it is essential to understand the fundamental assumptions for reliable hydrodynamic analysis of these projects. This study examined the impact of the fully conserved momentum through tidal structures using a novel approach. The method was applied to 2D and 3D versions of the regional model of Swansea Bay tidal lagoon, examining two different types of velocity distribution at turbine exit. A simplified distribution significantly increased the velocity and length of the jet exiting the turbines during power generation. A realistic distribution gave more accurate results,...

2025, Proceedings of the World Renewable Energy Congress – Sweden, 8–13 May, 2011, Linköping, Sweden

This study focuses on far-field hydro-environmental impacts of turbine arrays, with different shapes located in the Severn Estuary and Bristol Channel, UK, using a dynamically linked 1-D/2-D hydroenvironmental model. The estuary, including the Bristol Channel, is approximately 200 km long and has the third highest rise and fall of tide in the world, with typical spring tidal range of over 14 m, whilst the spring tidal currents in the estuary are well in excess of 2 m/s. There are a number of tidal renewable energy options being considered around the Severn Estuary, including but not limited to: tidal stream turbines, offshore tidal impoundments and a barrage -at various locations. The model was used to predict the hydrodynamic, sediment transport and water quality processes as well as power output predictions. In order to simulate the impact of the tidal stream turbines, the model was refined and the turbines were included as momentum sinks in the momentum equation. This study shows that the impact of the arrays on the water levels was negligible. However, the impact on velocities was more significant and the flow was retarded both upstream and downstream of the arrays, whilst it was faster on the side of the arrays. It was found that changes in the suspended sediment concentrations did not follow a simple pattern and that more detailed model studies are required to achieve a better understanding of this process. Finally, it was found that the power generated was dependent on the array layouts with the power output of different arrays used in this study varied by up to 20%.

2025, Applied Energy

Xu e, Jin gjin g, Ah m a di a n, R ez a , Jon e s , O w e n a n d F alc o n er, Ro g e r A. 2 0 2 1. D e si g n of ti d al r a n g e e n e r g y g e n e r a tio n s c h e m e s u si n g a g e n e ti c al g o ri t h m m o d el.

2025, Applied Energy

2025, Energies

Marine renewable energy, including tidal renewable energy, is one of the less exploited sources of energy that could contribute to energy demand, while reducing greenhouse gas emissions. Amongst several proposals to build tidal range structure (TRS), a tidal lagoon has been proposed for construction in Swansea Bay, in the South West of the UK, but this scheme was recently rejected by the UK government due to the high electricity costs. This decision makes the optimisation of such schemes more important for the future. This study proposes various novel approaches by breaking the operation into small components to optimise the operation of TRS using a widely used 0-D modelling methodology. The approach results in a minimum 10% increase in energy output, without the inclusion of pumping, in comparison to the maximum energy output using a similar operation for all tides. This increase in energy will be approximately 25% more when pumping is included. The optimised operation schemes are ...

2025, Computers & Geosciences

In this study, enhancements to the numerical representation of sluice gates and turbines were made to the hydro-environmental model Environmental Fluid Dynamics Code (EFDC), and applied to the Severn Tidal Power Group Cardiff-Weston Barrage. The extended domain of the EFDC Continental Shelf Model (CSM) allows far-field hydrodynamic impact assessment of the Severn Barrage, pre-and post-enhancement, to demonstrate the importance of accurate hydraulic structure representation. The enhancements were found to significantly affect peak water levels in the Bristol Channel, reducing levels by nearly 1 m in some areas, and even affect predictions as far-field as the West Coast of Scotland, albeit to a far lesser extent. The model was tested for sensitivity to changes in the discharge coefficient, C d , used in calculating discharge through sluice gates and turbines. It was found that the performance of the Severn Barrage is not sensitive to changes to the C d value, and is mitigated through the continual, rather than instantaneous, discharge across the structure. The EFDC CSM can now be said to be more accurately predicting the impacts of tidal range proposals, and the investigation of sensitivity to C d improves the confidence in the modelling results, despite the uncertainty in this coefficient.

2025, Sustainability

There is a trend towards harvesting tidal energy in shallow water. This study examined how tidal energy can be harvested using a device of oscillating cylinders inspired by the roots of mangroves. A specific focus was placed on optimising the configuration of these devices, informed by the computational fluid dynamics (CFD) analysis of wake interference in the von Kármán vortex street of the cylinders. A maximum efficiency of 13.54% was achieved at a peak voltage of 16 mV, corresponding to an electrical power output of 0.0199 mW (13.5% of the hydrokinetic energy of the water) and a power density of 7.2 mW/m2 for a flow velocity of 0.04 m/s (Re=239). The configuration of upstream cylinders proved to have a significant impact on the power generation capacity, corroborated further in CFD simulations. The effect of wake interference was non-trivial on the magnitude and quality of power, with tandem arrangements showing the largest impact followed by staggered arrangements. Though with c...

2025, Ocean Engineering

In this paper, 3-D effects on the performance of the Hunter turbine have been investigated by means of numerical simulations. It was observed that there is always a performance gap between results from 2-D and 3-D models. However, with increasing aspect ratio, the uniformity of the turbine performance along the entire span was effectively improved. Moreover, at higher flow coefficients, the pressure distributions of all turbines had similar profiles. A correction factor is defined that is related to the turbine height as well as the diameter. With the aid of this definition, the performance results for all Hunter turbines equipped with six blades could be collapsed into a single relationship with flow coefficient. It was also found that the overall level of torque fluctuation in the 2-D model is far less than those in 3-D models, while the 3-D torque fluctuation decreases with increasing aspect ratio.

2025

The present study examined the usability of ETOPO1 digital elevation model for small scale maps. The horizontal generalization of the contour lines generated from ETOPO1 was based on a geoinformatics algorithm. The authors gave the reduction values of simplification for the algorithm, and assigned these values to each map scale. The vertical generalization was examined by a diagram made on the frequency of the depths. The contour lines of the presented maps were based on the most frequent values of depths, though other criteria were also considered. The calculated values were compared with the earlier assigned values for the whole world. The examined area was the Arctic Ocean; therefore, the determined calculated values are valid for this region only.

2025, FUDMA Journal of Sciences (FJS)

Tidal analysis involves the computation of tidal constants (phase lag (g) and amplitude (H)) of tidal constituents at a location. This study focuses on the assessment of the stability of g and H for the Bonny port which is the only standard tidal port in Nigeria. Monthly analysis of tidal observations was carried out with 1980, 1994 and 2018 year's data using Least Squares Method (LSM) of Harmonic Analysis with MATLAB programming codes. The observation equation technique of LSM is adopted; the dimension of the Normal (N) matrix equations obtained for the monthly analysis is 72 × 56 i.e. 72 rows, and 56 columns. The N matrix is inverted and gave results for mean sea level (MSL) and g and H of 28 primary constituents of tide. Four major constituents of tide (M2, S2, K1 and O1) remain stable throughout the analysis. The mean of g and H obtained for each year was observed to be almost equal to the mean obtained from the three-year data. The maximum residuals and spreads of the computed g and H over the period of study show that g and H at Bonny are stable and that results from accurately analyze one-month data observation can be employed for tidal prediction for several years. Therefore, it can be concluded that the g and H for M2, S2, K1 and O1 are stable and that the type of tide (F) at Bonny port is semidiurnal since the computed F is 0.16 which is < 0.25.

2025, Journal of Marine Science and Engineering

In the context of harvesting tidal stream energy, which is considered a promising source of renewable energy due to its high energy density, stability, and predictability, this paper proposes a review-based roadmap investigating the use of data-driven techniques, more specifically machine learning-based approaches, to detect and estimate the extent of biofouling in tidal stream turbines. An overview of biofouling and its impact on these turbines will be provided as well as a brief review of current methodologies and techniques for detecting and estimating biofouling. Additionally, recent developments and challenges in the field will be examined, while providing several promising prospects for biofouling detection and estimation in tidal stream turbines.

2025, Journal of Marine Science and Engineering

2025, Bulletin of the American Physical Society

Power measurements in a scale model wind farm: Results from varying array size, arrangement, spacing, and setpoints DAN HOUCK, ED-WIN COWEN, Cornell University -The current trend in wind energy research is to optimize wind farms as opposed to optimizing individual turbines. There is also an emerging idea to consider the wind turbines themselves as actuators that can be used to intentionally and beneficially manipulate the flow to improve the power output of the wind farm. To this end, we completed a series of experiments with an array of 18 model-scale wind turbines in a 2 m wide flume testing changes in the number, arrangement, and spacing of the turbines as well as the setpoint, or power production, of each turbine. Each treatment case is compared to a similar control case that was arranged and operated more conventionally with all turbines attempting maximum power production. A highly accurate torque transducer provides calibrations allowing non-intrusive mechanical power measurements of each turbine. Comparisons are made on the basis of overall power output, array efficiency (total power output of the N-turbine array divided by N of an upstream turbine operating at max power), and power density (power per area). Particle image velocimetry (PIV) further reveals the fluid dynamics at work to create any improvements in power.

2025, Bulletin of the American Physical Society

2025

Lashy Sound is a small channel in Orkney, Scotland, where a tidal stream energy development is planned. This study uses numerical modelling to investigate the energy resource of the Sound and the effects on the flow of removing this power. A new 3D regional-scale hydrodynamic model of the area was built using the MIKE software and was used to study Lashy Sound. A standard momentum sink approach was used to represent tidal energy converters. It is estimated that the maximum possible yield from this channel from the M2 tidal constituent alone is 23 MW mean and 61 MW peak power, although this would require an unrealistic and uneconomic arrangement of tidal turbines. The 30 MW capacity that is planned is predicted to be feasible, and the environmental effects of both large and small arrays are discussed. Keywords—MIKE, hydrodynamics, resource assessment, environmental impact

2025, International Journal of Marine Energy

The Goto Islands in Nagasaki Prefecture, Japan, contain three parallel channels that are suitable for tidal energy development and are the planned location for a tidal energy test centre. Energy extraction is added to a 3D numerical hydrodynamic model of the region, using a sub-grid momentum sink approach, to predict the effects of tidal development. The available resource with first-generation turbines is estimated at 50-107 MW peak output. Spreading turbine thrust across the whole cross-section to prevent bypass flow results in a 64% increase in peak power in one channel, highlighting the importance of 3D over 2D modelling. The energy available for extraction in each strait appears to be independent of the level of extraction in other straits. This contrasts with theoretical and numerical studies of other multi-channel systems. The weak interactions found in this study can be traced to the hydraulic effects of energy extraction not extending to neighbouring channels due to their geometry.

2025, HAL (Le Centre pour la Communication Scientifique Directe)

This study will give an overview of high-resolution Irish local scale models. The Irish Marine Institute implemented the Regional Ocean Modelling System (ROMS) to coastal waters on the west coast of Ireland. Out of the six models, details of three are presented. The models are: Connemara, Galway Bay and Bertraghboy Bay with most recent developments including the implementation of wetting/drying algorithm. Implementation of a realistic bathymetry for Connemara and Galway models wetting/ drying algorithm has resulted in better validation against acoustic Doppler current profilers (ADCPs). The models implemented with a wetting and drying algorithm have shown better agreement against ADCPs.

2025

Tidal Stream Devices (TSDs) are relatively new renewable energy converters. To date only a few prototypes, primarily horizontal-axis turbine designs, are operational; therefore, little reliability data has accumulated. Pressure to develop reliable sources of renewable electric power is encouraging investors to consider the technology for development. There are a variety of engineering solutions under consideration, including floating tethered, submerged tethered, ducted sea-bed bottom-mounted and sea-bed pile-mounted turbines, but in the absence of in-service reliability data it is difficult to critically evaluate comparative technologies. Developing reliability models for TSDs could reduce long-term risks and costs for investors and developers, encouraging more feasible and economically viable options. This research develops robust reliability models for comparison, defining TSD reliability block diagrams (RBD) in a rigorous way, using surrogate reliability data from similarly-rated wind turbines (WTs) and other relevant marine and electrical industries. The purpose of the research is not to derive individual TSD failure rates but to provide a means of comparison of the relative reliabilities of various devices. Analysis of TSD sub-assemblies from the major types of TSDs used today is performed to identify criticality, to improve controllability and maintainability. The models show that TSDs can be expected to have lower reliability than WTs of comparable size and that failure rates increase with complexity. The models also demonstrate that controls and drive train sub-assemblies, such as the gearbox, generator and converter, are critical to device reliability. The proposed developed models provide clear identification of required changes to the proposed TSD system designs, to raise availability, including duplication of critical systems, use of components developed for harsh environments and migration of equipment onshore, wherever practicable.

2025, Energies

Tidal energy converter (TEC) arrays in tidal channels generate complex flow phenomena due to interactions with the local environment and among devices. Models with different resolutions are thus employed to study flows past TEC farms, which consider multiple spatial and temporal scales. Simulations over tidal cycles use mesoscale ocean circulation models, incorporating a thrust coefficient to model the momentum sink that represents the effects of the array. In this work, we propose an expression for a thrust coefficient to represent finite-sized farms of TEC turbines at larger scales, C t F a r m , which depends on the spatial organization of the devices. We use a coherent-structure resolving turbulence model coupled with the actuator disk approach to simulate staggered turbine configurations in more detail, varying the separation among devices and the ratios between the channel depths and hub heights. Based on these simulations, we calculate the resultant force for various subsets ...

2025

Pemanfaatan energi arus laut merupakan salah satu cara yang potensial untuk penghematan konsumsi energi fosil sebagai sumber utama pembangkit listrik pada dunia industri salah satunya FSO Ladinda fasilitas marine milik EMP Malacca Strait S.A. yang berada di Selat Lalang Propinsi Riau. Tujuan dari studi ini untuk mengetahui kondisi arus Selat Lalang dan besar potensi energi listrik yang dapat dihasilkan dan dimanfaatkan, sehingga dapat diketahui berapa jumlah turbin yang dapat di-farming dan selanjutnya dapat menentukan konsep perancangan PLTAL. Metode dalam studi ini berupa pengumpulan data sekunder, pemodelan arus selanjutnya perhitungan potensi energi dan pemilihan lokasi peletakan turbin dilanjutkan dengan mengidentifikasi konsep perancangan PLTAL. Lokasi rencana penempatan turbin Darrieus BPPT LHI cukup memenuhi syarat yakni di kedalaman ± 25 meter. Untuk mengetahui besar kecepatan arus di lokasi studi dilakukan pemodelan hidrodinamika menggunakan MIKE 21. Hasil pemodelan menunj...

2025, Journal of Marine Science and Engineering

An area has been designated for demonstrating the utility of marine hydrokinetic turbines in Minas Passage, Bay of Fundy. Marine renewable energy may be useful for the transition from carbon-based energy sources, but there is concern for the safety of fish that might encounter turbines. Acoustic receivers that detect signals from acoustically tagged fish that pass through the tidal demonstration area and the detection efficiency of tag signals might be used to estimate the likelihood of fish encountering marine hydrokinetic turbines. The method requires that tagged fish passing through the development area will be reliably detected by a receiver array. The present research tests the reliability with which passing tags are detected by suspending tags beneath GPS-tracked drifters. Drifters carrying high residency Innovasea tags that transmitted every 2 s were usually detected by the receiver array even in fast currents during spring tides but pulse-position modulation tags were inadeq...

2025

The OES, also known as the Implementing Agreement on Ocean Energy Systems, functions within a framework created by the International Energy Agency (IEA). Views, findings, and publications of the OES do not necessarily represent the views or policies of the IEA Secretariat or of all its individual member countries. Neither the authors nor the participating organizations nor the funding organizations make any warranty or representations, expressed or implied, with respect to use of any information contained in this report, or assume any liabilities with respect to use of or for damages resulting from the use of any information disclosed in this document.

2025

This paper describes the structural, design of a tidal turbine blade the study consists of measuring energy creation if a mechanism were to be placed in the sea flow below tidal areas. Growing concern over the threat of global climate change has led to be increased interest in research and development of renewable energy technologies. Most tidal current turbine design are focused on middle and large scale for deep sea, less attention was paid in low water level channel, such as the region around the islands, coastal seas and rivers. The ocean provides a vast source of potential energy resources and as renewab le energy. Tidal energy ortidal power is the power achieved by capturing the energy contained in moving water mass due to tides. two types of tidal energy can be extracted kinetic energy of currents between ebbing and surging tides and potential energy from the different in height between high and low tides.through this energy may not be able to be obtained all of the time, onl...

2025, International Journal of Offshore and Coastal Engineeing

Nowadays tidal current energy conversion system (TCECS) is being developed with a capacity of 100 kW for Indonesian waters. The design process is based on the results of field measurements, i.e., ocean currents, tides, ocean waves, and bathymetry. This paper aims to explain the experiences when collecting oceanography data in a potential site for TCECS. The survey method is that the equipment placed on the seabed will emit signals that can record flow and wave data according to the desired time and depth. The survey process, especially for the tidal current energy application, requires good preparation so as not to fail. The results of this paper explain the challenges and highlight the steps. These are technical, environmental, and survey permits. The technical aspects are tool stability, buoyancy effects, visualization tools with an underwater camera system, seawater brightness, and sedimentation. Environmental aspects are big waves, strong currents, and weather. The survey permit aspects are destruction and conservation area. Therefore, before the survey, safety procedures or documents must be made in the form of HIRA (Hazard Identification and Risk Analysis). The experiences of this survey are a novelty consideration for other surveyors in the tidal current energy aspect.

2025, Renewable Energy

Tidal energy is one of the most predictable forms of renewable energy. Although there has been much commercial and R&D progress in tidal stream energy, tidal range is a more mature technology, with tidal range power plants having a history that extends back over 50 years. With the 2017 publication of the "Hendry Review" that examined the feasibility of tidal lagoon power plants in the UK, it is timely to review tidal range power plants. Here, we explain the main principles of tidal range power plants, and review two main research areas: the present and future tidal range resource, and the optimization of tidal range power plants. We also discuss how variability in the electricity generated from tidal range power plants could be partially offset by the development of multiple power plants (e.g. lagoons

2025, Renewable Energy

The study investigates the impact that construction of a Severn Barrage in the Severn Estuary, on the west coast of the UK, might have on local wave conditions. Implementation of a barrage will impact on tidal currents and water elevations in the wider region. There is strong tidal modulation of wave conditions under the natural regime and therefore barrage-induced changes to tidal conditions could affect wave modulation in the region. This paper uses Swan, an open source 3rd generation spectral wave model, to investigate the possible impacts of construction of a barrage on tidal modulation of the wave conditions. It is found that current variations, rather than water level variations, are the dominant factor in tidal modulation of wave conditions. Barrage implementation does not substantially change the modulation of the wave period or direction. However, barrage implementation does affect the tidal modulation of wave heights in the area of interest. The tidal modulation of the wave heights is generally reduced compared to the natural case; the peaks in the wave heights on an incoming tide are slightly lowered and there is lesser attenuation in wave heights on the outgoing tide. This modulation leads to net changes in the wave heights over one tidal cycle. For all of the tested wave conditions, this net change is small for the majority of the tested domain, namely to within ±5% of the no barrage case. There are some areas of greater change, most notably larger net increases in the wave heights near the North Somerset coast where the post construction net wave height increase over a tidal cycle approach 20% of the pre-construction conditions. These changes do not impact coastal flooding because the wave height increase is not co-incident with high tide. Importantly, the maximum wave height is not increased and thus the likelihood of extreme events is not increased. The area of greatest reduction is between Swansea and Porthcawl. Changes over a neap tidal cycle show similar patterns of net change, but the modulation over the tidal cycle is different; primarily the magnitude of modulation is half that for the spring tide case and the shape is altered in some locations.

2025, Applied Energy

The Severn Estuary has a spring tidal range approaching 14 m and is regarded as having one of the highest tidal ranges in the world. Various proposals have been made regarding the construction of a tidal barrage across the estuary to enable tidal energy to be extracted. The barrage scheme originally proposed by the Severn Tidal Power Group (STPG) would be the largest project for tidal power generation in the world if built as proposed. Therefore, it is important to study the impact of different operating modes for this barrage on the tidal power output and flood inundation extent in the estuary. In this paper, an existing twodimensional hydrodynamic model based on an unstructured triangular mesh has been integrated with a new algorithm developed for the estimation of tidal power output, which can account for three barrage operating modes, including ebb generation, flood generation, and two-way generation. The refined model was then used to investigate the impact of different barrage operating modes on the tidal power output and the associated extent of flood inundation along the Severn Estuary. Predicted results indicate that the mode of flood generation would produce the least electrical energy and cause a larger reduction in the maximum water levels upstream of the barrage. Two-way generation would provide an improvement to these conditions, and produce an equivalent amount of electricity to that from ebb generation, with a low installed capacity and a small loss of intertidal zones. Therefore, the mode of ebb generation or two-way generation would appear to be a preferred option for power generation, because both would offer benefits of acceptable electrical energy and reduced flood risk.

2025, Applied Energy

In recent years, there have been growing international challenges relating to climate change and global warming, with a conflict developing between the need to create a low-carbon economy and rapid depleting reserves of fossil fuels. In addition to these challenges there continues to be the added complexity of a significant global increase in energy demand. Marine renewable energy from tidal barrages is carbon-free and has the potential to make a significant contribution to energy supplies now and in the future. Therefore, it is appropriate to evaluate the total energy that can be extracted from such barrages. In this study two different methods are proposed to estimate the total annual energy output from a barrage, including a theoretical estimation based on the principle associated with tidal hydrodynamics, and a numerical estimation based on the solutions obtained from a 2D hydrodynamic model. The proposed Severn Barrage in the UK was taken as a case study, and these two methods were applied to estimate the potential annual energy output from the barrage. The predicted results obtained using the two methods indicate that the magnitude of the annual energy output would range from 13 to 16 TWh, which is similar to the value of 15.6 TWh reported by the Department of Energy and Climate Change, in the UK. Further investigations show that the total annual energy output would increase by about 15% if a higher discharge coefficient were to be adopted for the sluice gates, or if the turbine performance were to be improved. However, the estimated annual energy output could exceed the value of 16 TWh if future technological advances in both sluice gate construction and turbine performance are included.

2025, Applied Ocean Research

A 3D numerical modelling study to investigate the existing hydrodynamic regime of the Pentland Firth Inner Sound Channel, Scotland, UK is presented. Hydrodynamics that govern some sensitive sedimentary deposits in the Inner Sound Channel are discussed. A 3D hydrodynamic model Delft3D is set up for Pentland Firth, located between Orkney Islands and mainland Scotland and a full sensitivity analysis of the numerical model is carried out. The current model set up sufficiently captures the existing hydrodynamics during a full spring-neap tidal cycle inside Pentland Firth. Using model results, the 3D structure of the dynamics of the tidal flows in the Inner Sound Channel is investigated. The temporal variability of tidal flows, the residual tidal flows in the channel and local flow interactions with the Island of Stroma are described. It is proved that the tidally dominant flows drive the sediment transport gradient model to explain the principle maintenance mechanisms of two island-associated sandbanks present in the Inner Sound. The present study provides detailed information on the physics of the tidal regime in the Inner Sound and explains the presence of sandbanks in an area of high tidal flows. Due to extremely high tidal flows, Inner Sound is considered as one of the most favourable sites for tidal energy extraction in the UK. The findings of this study will be very useful in assessing the significance of impacts of future tidal energy extraction on natural hydrodynamics and sediment dynamics of the area.

2025, Indian Journal of Science and Technology

2025, International Marine Energy Journal

This work is a preliminary study to find some sites for the potential use of tidal stream energy and their associated currents in the Chubut coast. In addition, an evaluation of the energy resource of the Chubut Gulfs is made. The possibility of energetic utilization of the tides is achieved by transforming the displacement movement into a rotation movement by means of a hydrokinetic turbine. The energy can be extracted analogously to that of wind energy; therefore, it is not necessary to build a dam, avoiding the environmental and economic disadvantages it represents. Even though the results presented in this paper have significantly improved our understanding of tidal dynamics in this region, the collection of more observations, particularly in the interior and at the mouths of the Gulfs, is necessary to develop and fully shape tidal potential into power generation in the region.

2025, Renewable Energy

Scale model tests were conducted on a three bladed horizontal axis tidal turbine in a large tow tank facility at the United States Naval Academy. Performance characteristics are presented for a turbine towed at a constant carriage speed for cases with and without surface waves. Intermediate waves were modeled that are representative of swells typically found on the continental shelf of the United States eastern seaboard. The oscillatory wave velocity present in the water column results in significant variations in measured turbine torque and rotational speed as a function of wave phase. This in turn produces cyclic variations in tip speed ratio and power coefficient. The power coefficient over the entire wave phase did not show a difference from the experiments without waves for a range of tip speed ratios, as reported in previous studies. The waves limited the lower range of tip speed ratios at which the turbine could operate. These results highlight the impact of surface waves on turbine design and performance, and the importance of understanding the site-specific wave conditions.

2025, Proceedings of the Pakistan Academy of Sciences: A. Physical and Computational Sciences

Electrical power generation by tidal energy provides various advantages. The energy is highly predictable, has less impact on ecological pollution and provides an indefinite amount of renewable energy. The countries like Canada, China, Russia, South Korea and France are extensively utilizing tidal sources of energy for the generation of electrical energy. A suitable site (where less construction is required), adequate tidal range and sufficient bathymetry; are the basic requirements for the installation of a tidal power plant however sometimes there is no tidal data available for suitable sites, like Khor Kalmat tidal lagoon in Pakistan. Therefore, the first time study is conducted to assess the tidal energy resources of the naturally blessed lagoon, Khor Kalmat, which is located in the Baluchistan province of Pakistan, by using geostatistical modeling. A geostatistical model is developed to estimate the tidal energy potential at Khor Kalmat by using observed data of five available ...

2025, Proceedings of the Institution of Civil Engineers

Financial viability and political will ultimately determine if tidal range power schemes are developed. This research aims to demonstrate a robust system to make initial estimates of capital costs for tidal range schemes that can be compared between systems and options. A levelised cost of energy (LCOE) is used to compare a tidal range barrage (Morecambe Bay) and a coastal tidal lagoon (North Wales); the schemes are set in context with other common energy sources. The results show the Morecambe Bay barrage generates marginally more electricity than the North Wales coastal lagoon and has a shorter impoundment at lower cost. However, the economic arguments for both schemes are similar; both are viable as the LCOE shows. Despite being shown to be financially viable, the sources of funding may remain a problem. Financial returns and two potential public funding mechanisms are discussed. The approach using two simple models makes a strong case for more detailed analysis and, in the current environmental, economic, and social climate serious decisions must be taken.  Initial estimation of capital cost for tidal range case studies using 5-main components  Optimisation of generator rating, number of turbines and sluices  Levelised cost of energy (LCOE).  Revenue and funding mechanisms.

2025

The battle against climate change is no longer just a fight for scientific truth or technological progress. It is a political power struggle. While the Earth warms and extreme weather intensifies, global leaders continue to fund wars,... more

2025, Research Journal of Applied Sciences

Abstract: The world is heavily dependent on fossil fuels since most of its energy requirements are fulfilled by conventional methods of burning these fuels. The energy demand is increasing by day with growing population. The energy production by fossil fuels is devastating the environment and survival of life on globe is endangered. The renewal energy technologies are vital to ensure future energy sustenance and environmental issues. Ocean is a vast resource of renewable energy. The technology today makes it possible to ...

2025, Energies

Ocean energy holds out great potential for supplying remote maritime areas with their energy requirements, where the grid size is often small and unconnected to a continental grid. Thanks to their high maturity and competitive price, solar and wind energies are currently the most used to provide electrical energy. However, their intermittency and variability limit the power supply reliability. To solve this drawback, storage systems and Diesel generators are often used. Otherwise, among all marine renewable energies, tidal and wave energies are reaching an interesting technical level of maturity. The better predictability of these sources makes them more reliable than other alternatives. Thus, combining different renewable energy sources would reduce the intermittency and variability of the total production and so diminish the storage and genset requirements. To foster marine energy integration and new multisource system development, an up-to-date review of projects already carried out in this field is proposed. This article first presents the main characteristics of the different sources which can provide electrical energy in remote maritime areas: solar, wind, tidal, and wave energies. Then, a review of multi-source systems based on marine energies is presented, concerning not only industrial projects but also concepts and research work. Finally, the main advantages and limits are discussed.

2025, Energies

The global tidal energy resource for electricity generation is small, and converting tidal kinetic energy to electricity is expensive compared to solar-photovoltaic or land-based wind turbine generators. However, as the renewable energy content in electricity supplies grows, the need to stabilise these supplies increases. This paper describes tidal energy’s potential to reduce intermittency and variability in electricity supplied from solar and wind power farms while lowering the capital expenditure needed to improve dispatchability. The paper provides a model and hypothetical case studies to demonstrate how sharing energy storage between tidal stream power generators and wind or solar power generators can mitigate the level, frequency, and duration of power loss from wind or solar PV farms. The improvements in dispatchability use tidal energy’s innate regularity and take account of tidal asymmetry and extended duration low-velocity neap tides. The case studies are based on a nation...

2025

This paper presents an overview and progress of a recently commenced three year project funded by the Australian Renewable Energy National Agency led by the Australian Maritime College, (University of Tasmania), in partnership with CSIRO and University of Queensland. The project has a strong industry support (OpenHydro Ltd, Atlantis Resources Limited, MAKO Tidal Turbines Ltd, Spiral Energy Corporation Ltd and BioPower Systems Ltd) and aims at assessing the technical and economic feasibility of tidal energy in Australia, based on the best understanding of resource achievable. The project consists of three interlinked components to support the emerging tidal energy sector. Component 1 will deliver a National Australian high-resolution tidal resource assessment; in Component 2, case studies at two promising locations for energy extraction will be carried out; lastly, Component 3 will deliver technological and economic feasibility assessment for tidal energy integration to Australia’s e...

2025, Energies

The development of tidal energy in Australia is still a challenge with few studies performed on the characterisation of the resource, due to the difficulty to acquire data and uncertainties about the influence of this anthropogenic activity on the marine environment. Changes in flow could lead to alterations in sediment transport and have further influence on the marine habitat. A case study in a promising area, Banks Strait (Australia), was created using high resolution 2D and 3D models validated against in situ data to investigate changes to hydrodynamic conditions with two scenarios of tidal farms (100 and 300 turbines). Comparison between 2D and 3D is performed to find the best compromise between model accuracy and computational time for preliminary assessment. Changes to current speed and bed shear stress over a 35 day period were found to be localised around the tidal farms and did not extent more than 7 km from the farm (300 turbines) for both 2D and 3D. The results showed th...

2025, Renewable Energy

The development of tidal energy converters, and particularly floating tidal energy converters, is an area of increased development in recent years. Testing of a floating tidal energy device over winter 2017/18 led to an opportunity to record and examine strain of a full scale composite turbine blade under operational conditions, with comparison of generating and parked behaviours. Comparison of the recorded data shows that blade strain correlates well with both torque and thrust over the averaging periods specified in IEC62600-200, although examination of frequency spectra generated from the strain data show that higher frequency fluctuations in strain are not necessarily detectable in the larger scale thrust and torque recordings with this particular measurement arrangement. The need for well synchronised clocks on recording systems is also highlighted, along with a cross-correlation method used to recover the alignment of data from different systems to allow comparison between them over periods of a similar order of magnitude to the clock skew between the systems.

2025, Energy

Temporal variability in renewable energy presents a major challenge for electrical grid systems. Tides are considered predictable due to their regular periodicity; however, the persistence and quality of tidal-stream generated electricity is unknown. This paper is the first study that attempts to address this knowledge gap through direct measurements of rotor-shaft power and shore-side voltage from a 1MW, rated at grid-connection, tidal turbine (Orkney Islands, UK). Tidal asymmetry in turbulence parameters, flow speed and power variability were observed. Variability in the power at 0.5Hz, associated with the 10-minute running mean, was low (standard deviation 10-12% of rated power), with lower variability associated with higher flow speed and reduced turbulence intensity. Variability of shore-side measured voltage was well within acceptable levels (~0.3% at 0.5Hz). Variability in turbine power had <1% difference in energy yield calculation, even with a skewed power variability distribution. Finally, using a "t-location" distribution of observed fine-scale power variability, in combination with an idealised power curve, a synthetic power variability model reliably downscaled 30 minute tidal velocity simulations to power at 0.5Hz (R 2 = 85% and ~14% error). Therefore, the predictability and quality of tidal-stream energy may be undervalued in a future, high-penetration renewable energy, electricity grid.