Tidal Barrage Research Articles

Impact of tidal fluctuations on bacterial community structure in Wuyuan Bay: A comparative analysis of waters inside and outside the tidal barrage.

The tidal barrage at Wuyuan Bay effectively mitigated the odor from the tidal flat during ebb tide, however, its effect on bacterial community structure in waters are still unclear. In this study, high-throughput sequencing was used to analyze the structure of the microbial community in waters inside and outside the tidal barrage during flood and ebb tides. Results showed bacterial diversity was higher in water outside the barrage during flood tide. The dominated species at phylum and genus levels were various in waters inside and outside the tidal barrage during flood and ebb tides. The water inside during ebb tide (E1) were dominated by two cyanobacterial genera, Cyanobium_PCC-6307 (42.90%) and Synechococcus_CC9902 (12.56%). The microbial function, such as porphyrin and chlorophyll metabolism and photosynthesis, were increased in E1. Norank_f__Nitriliruptoraceae was identified as differential microorganism in waters inside the barrage. Inorganic nitrogen and nonionic ammonia were significantly high in E1, and were negatively correlated with norank_f__Nitriliruptoraceae. These results suggest tidal barrage blocks water exchange, resulting in the accumulation of nutrients in Wuyuan Bay. Consequently, the environment became favorable for the growth of cyanobacteria, leading to the dominance of algae in the water inside the barrage and posing the risk of cyanobacterial bloom. Higher Nitriliruptoraceae inside the barrage might be a cue for the change of water quality.

Three-Dimensional Hydrodynamic and CFD Modeling of a Tidal Barrage Power Plant without Sluicing in Buenaventura, Colombia

Recent research revealed the potential of tidal energy in the central coastal region of the Colombian Pacific. Buenaventura City, located in the Valle del Cauca department in Colombia, has an important opportunity to develop tidal power technologies near its marine coastal areas. This research implemented a 3D hydrodynamic model for simulating the hydrodynamics of the Buenaventura Bay to provide data as input for evaluating the hydraulics of a tidal barrage without sluicing through CFD modeling. According to the results, the velocities across the gates during Syzygy (April 2021) showed impressive velocities between 9 and 11 m/s, which suggest a high possibility of producing electricity through tidal turbines. The mean behavior of velocities in the gates pointed to values of 3 and 5 m/s in most of the cases. The results during the Stoa condition were interesting because flow velocities higher than 1 m/s were not expected. This is promising because the plant might produce electricity even during the Stoa condition. For the first time, the results of this research suggest that there exists a high possibility of implementing tidal barrage plants in Buenaventura City, Colombia.

Tidal Range Barrage Design and Construction

The west coast of Great Britain has the potential for barrages to create tidal range reservoirs that both facilitate electricity generation and prevent flooding from sea level rise. Seawater flows into and out of the reservoir, or impoundment, through turbines and sluices. The impounded water follows the natural tidal sequence but with a delay which creates a head between the two bodies of water. Traditional designs for barrages use earth embankments, with impermeable cores and rockfill protection. More recently, breakwaters and jetties have been constructed using precast concrete vertical caissons. A novel design using horizontal precast caissons is described and evaluated. Wave forces are estimated using Goda’s method for a vertical breakwater to assess their impact on stability and ground-bearing pressures. The stability of the barrage is checked for hydrostatic and wave forces. The volumes of materials and relative costs are presented. Precast caissons are found to be viable financially and should be both quicker and easier to construct and install. The horizontal caissons show advantages over the vertical type, and although untried, they should be easier to construct than submerged tube tunnels. Further work is needed to validate the design, including dynamic modelling and detailed construction assessment to confirm the cost rates.

Numerical assessment of tidal potential energy in the Brazilian Equatorial Shelf

The Brazilian Equatorial Shelf (BES) is one among the macrotidal regions worldwide. This study used a high-resolution numerical configuration of the ocean model ROMS (Regional Ocean Modeling System) forced with realistic surface and lateral forcing, as well as with tides and river discharges. Tidal heights of more than 2 m were found in three regions in BES due to the large tidal amplification across the estuarine channels inside each region: Amazon, Pará, and Maranhão, and for a considerable time fraction. Heights between 4 and 5 m occurred with a frequency greater than 20%–30% in some regions. All hypothetical barrages proposed in this study were capable of an annual power production, in two-way mode, higher than La Rance (533 GWh year−1, two-way operation, France) and Sihwa (553 GWh year−1, flood-only operation, South Korea), except one with the same production as Sihwa barrage. The installation effort was evaluated using the Gibrat ratio, the ratio between the length of the barrage and its annual energy production. Among the proposed barrages, the most efficient ones have an annual power generation greater than 1500 GWh year−1 and a Gibrat ratios between 1.17 and 3.26, much lower than the Gibrat ratio of Sihwa tidal barrage.

Tidal barrage operation optimization using moment-based control


 As decarbonization of energy systems becomes an imperative and the deployment of intermittent renewables increases, the operation of electrical grids becomes challenging. In this sense, tidal barrage schemes can supply clean and predictable energy with more flexibility than the more traditional wind and solar plants. However, the high infrastructure costs associated with tidal barrage plants hinders its deployment. An optimal operation is key to maximize energy output and assure the project’s feasibility.
 Recently, Ringwood and Faedo [3] introduced a novel approach to tidal barrage control by applying wave energy control techniques, with promising results. The model consists on a two-way tidal barrage scheme, where an analogy is made between latching/declutching algorithms applied in WEC control and holding/sluicing from tidal barrage. The optimization was done using the moment-based framework developed in [1] and [2], which can formulate linear and non-linear problems in a concave quadratic environment, thus allowing the application of efficient numerical solution algorithms. This preliminary study has a number of simplifying assumptions, leaving a pathway to further examine the optimal control problem.
 This paper extends the results of the analysis from [3] by adding complexities to the model. Crucially, the basin is modeled such as the area is a polynomial function of the water level, instead of assuming constant surface area. This will affect the operational head of the optimal solution, as the volume of water at the top of the basin will be higher than at the bottom. Another added constraint will be the minimum head that the turbine requires to generate electricity. Furthermore, a cost function is introduced to penalize the energy consumption of the sluice gates, as shown in figures 1.a) and 1.b). This not only increases the accuracy of the model, but in many cases improves the convergence of the algorithm by adding a quadratic term. Figure 2 shows the value of the overall energy yield (as a fraction of the energy output without penalty) and simulation run time (as a fraction of the run time without penalty) with different penalty coefficients.
 1.a) Sluice gate area without considering cost function
 1.b) Sluice gate area with penalty factor of 3
 
 
 2. Energy and run time variations with penalty
 
 

Improving the power output estimation for a tidal power plant: a case study

The aim of this study is to analyse the importance of considering the variation in the discharge coefficient (Cd) of a sluice passage and the tidal current speed (i.e. the flow speed approaching the passage) in improving the estimation of power output for a tidal power plant. The simulation results, using a commercial computational fluid dynamics software package, Flow 3D, have shown that the Cd value of a sluice passage varies with the upstream (i.e. on the sea side of the impounded area) water level. In addition, the results of a case study carried out in the Taedong bay (Democratic People's Republic of Korea), using a zero-dimensional model, highlight the importance of considering variations in the tidal current speed as well as Cd when estimating the power output for a tidal power plant. In this study, a detailed scheme is proposed to consider the approach speed at each stage of filling, holding, generating and holding for the mode of ebb generation. It is hoped that the results of this study will help scientists, engineers and decision makers to accurately evaluate the tidal power output of tidal barrages and lagoons in many regions of the world.

Tidal range generation: combining the Lancaster zero-dimension generation and cost models

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) in the UK; 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.

Optimal planning of a micro‐grid containing tidal barrage equipped to the hydro‐pumps

AbstractDue to the advantages of micro‐grids including power losses and voltage drops reduction, reliability improvement and reduction in transmission network cost, numerous clean micro‐grids including renewable resources such as wind, tidal and solar are developed in different countries of world. The investment cost of the renewable energy‐based generation units especially tidal barrages is high, and to generate the cost‐effective electricity from the renewable resources, the optimization process should be performed. In this paper, optimal planning of a micro‐grid containing energy storage device and new mixture of renewable resources including tidal barrage and photovoltaic system is performed. For this purpose, optimal characteristics of barrage type tidal plant including number of turbines, sluices and hydro‐pumps, turbine tip and hub diameters and sluice width are determined to maximum energy of tidal plant is generated. Then, number of photovoltaic systems and batteries are obtained to supply the required load in minimum cost. To optimize the objective functions, different heuristic approaches including particle swarm, genetic and imperial competitive algorithms (ICAs) are applied, in the paper. To study the effectiveness of the proposed approach, optimal planning of a micro‐grid is performed. It is deduced from the numerical results that the particle swarm method has performed best in determining the optimal solution.

A Day-Ahead Scheduling Model of Power Systems Incorporating Multiple Tidal Range Power Stations

With the global trend to exploit more renewable energy sources, tidal range energy has been gaining more attention recently. This power generation technology is expected to reduce the share of fossil fuels and provide flexibility to the power system. With a pioneering tidal range generation project just granted in Wales and more proposals planned in Great Britain, it is important to study how the incorporation of multiple tidal range power stations will affect power system operation. In this paper, the role of tidal range energy generation in the future Great Britain power system is investigated based on a day-ahead scheduling model of power system incorporating multiple tidal range power stations. In the proposed model, tidal range power stations situated at different sites operate flexibly and in coordination, supporting the power system to reach the minimum operating cost. A case study based on the Great Britain electricity transmission system in 2030 with one tidal barrage and one tidal lagoon was investigated. The results showed that the coordination of flexible tidal range power stations can reduce the power system's operating cost. Furthermore, the energy-storage feature of tidal range power stations can act as a stable source of flexibility in the power system.

The Development of 10 kW Class Tidal Power Generator System - Focusing on Field Experiments with Pipelines

Along with the growing interest in renewable energy development, Korea’s west coast is one of the favorable regions for tidal power. Tidal power using tidal barrages that work like hydroelectric dams is a representative method of tidal power through long-term operation, but the promotion of tidal power projects is being delayed or stopped due to impacts on ecological changes, reproduction, water column processes and hydrology. In order to reduce the high construction cost and environmental cost problems caused by tidal power using tidal barrages, in this study, field experiments were conducted to develop and verify the performance of tidal power generation devices applicable to sea areas where dykes are already installed. As a result of conducting five cases of experiments using two water tanks, pipe lines, open channels, and water turbine and generator, the possibility of developing a power generation system capable of generating more than 10 kW output and more than 60% efficiency were confirmed. The results of this study can be used for small-scale tidal power by utilizing the existing dykes of the west coast.

Development and validation of an AI-Driven model for the La Rance tidal barrage: A generalisable case study

In this work, an AI-Driven (autonomous) model representation of the La Rance tidal barrage was developed using novel parametrisation and Deep Reinforcement Learning (DRL) techniques. Our model results were validated with experimental measurements, yielding the first Tidal Range Structure (TRS) model validated against a constructed tidal barrage and made available to academics. In order to proper model La Rance, parametrisation methodologies were developed for simulating (i) turbines (in pumping and power generation modes), (ii) transition ramp functions (for opening and closing hydraulic structures) and (iii) equivalent lagoon wetted area. Furthermore, an updated DRL method was implemented for optimising the operation of the hydraulic structures that compose La Rance. The achieved objective of this work was to verify the capabilities of an AI-Driven TRS model to appropriately predict (i) turbine power and (ii) lagoon water level variations. In addition, the observed operational strategy and yearly energy output of our AI-Driven model appeared to be comparable with those reported for the La Rance tidal barrage. The outcomes of this work (developed methodologies and DRL implementations) are generalisable and can be applied to other TRS projects. Furthermore, this work provided insights which allow for more realistic simulation of TRS operation, enabled through our AI-Driven model.

Three-dimensional hydrodynamic model of the Rance estuary (France) influenced by the world’s second largest tidal power plant

The Rance estuary is a small steep-sided ria, located in the Brittany coast of northern France, with a maximum spring tidal range of 13.5m and an average river discharge of 7m3/s. Taking advantage of this significant tidal range, the Rance tidal power station (RTPS) was built in the 1960s as the world’s first and largest tidal power plant, with peak output capacity of 240 Megawatts. It is currently the second world’s largest tidal power installation after the Sihwa-Lake tidal barrage. The RTPS has two active parts: a barrage of 6 sluice gates and a structure of 24 turbines. Despite a well-known effect of the plant on damping estuarine water levels, little attention has been given to currents vertical distribution and the plant's impact on the dynamics of freshwater-saltwater interface. Therefore, a three-dimensional model of the Rance estuary was developed. Moreover, currents and salinity measurements were carried out to validate the numerical model. Simulated and measured currents showed that (i)the RTPS induces an acceleration of flood currents directly upstream of the sluice gates and (ii)ebb currents are strengthened by the narrowness of the Saint-Hubert-Port. Finally, salinity analyses assessed the dynamics of the freshwater-saltwater interface which is pushed further upstream during summer.

Tidal barrage operational optimisation using wave energy control techniques

Tidal barrages have been used as a source of renewable energy since Medieval times, though the commercial utilisation of tidal barrages for electricity production began in 1966. In the intervening time, a number of techniques have been used to optimise the operation of tidal barrages, in order to maximise their utility, against set criteria, usually including maximisation of converted energy. This paper examines what can be learned from a sister renewable energy application, wave energy, in terms of the energy-maximising control schemes employed. Specifically, comparisons are made in terms of the characteristics of the primary energy excitation, the set of control protocols available, and the mathematical models used to describe each system. In order to provide a preliminary assessment of the potential for the use of wave energy control concepts, a sample case study is undertaken, where a popular wave energy control philosophy is used to optimise the operation of a tidal barrage.

Marine renewable energy devices and their control: An overview

Marine renewable energy (MRE) is a label that embraces a range of technologies used to harness ocean energy, including wave, tidal stream, tidal barrage, ocean thermal energy conversion (OTEC) and salinity gradient, as well as offshore wind (floating and fixed). For the current analysis, floating solar is omitted from the MRE set. With an increasing drive towards zero-carbon energy provision, and the need for complementarity with increasing penetration of wind and solar, the need to tap the vast available MRE resources has never been greater. Ultimately, the adoption of MRE energy harnessing technology is contingent on the cost of MRE being competitive with other renewable, and conventional, energy sources, in terms of Levelised Cost of Energy (LCoE). The value of appropriate control systems, which can maximise the energy conversion capability of MRE and give added value to the capital investment, has been identified as an important modulator of LCoE. This paper examines the range of control problems within the gamut of MRE technologies and documents commonality and contrasts, as well as the emergence of control problems that are unique to aspects of MRE

Pengaruh Ketinggian dan Panjang Saluran Air Laut terhadap Daya yang Dihasilkan pada Prototype Tidal Barrage

Kebutuhan energi listrik di Indonesia sangatlah penting mengingat keterbatasan sumber daya alam dan minimnya tenaga kerja membuat Indonesia sangat butuh peningkatan pembangkit listrik. Salah satu sumber energi yang dapat di konversi menjadi energi listrik adalah pasang surut air laut menggunakan metode tidal barrage. Penerapan Energi ini masih sangat sedikit di Indonesia tetapi ada beberapa wilayah yang berpotensi untuk diterapkannya pembangkit tersebut . Pembangkit listrik ini memanfaatkan energi tenaga pasang surut air laut untuk energi potensial yang terkandung dalam perbedaan tinggi dan rendahnya air laut karena fenomena alam yang terjadi dengan cara menjebak air pada bendungan dan kemudian menggerakkan turbin air yang dihubungkan dengan generator agar dapat menghasilkan energi listrik. Terkait dengan berapa output daya yang dihasilkan dapat diketahui dengan cara melihat pada ketinggian berapa level air yang menggerakkan turbin. Pembangkit ini termasuk jenis pembangkit ramah lingkungan karena dapat meminalisir kerusakan ekosistem alam dan bendugan, dapat dimanfaatkan untuk berbagai aktivitas. Untuk lebih mudah memahami metode ini maka perlunya dibuat prototype untuk mengetahui berbagai factor yang mempengaruhi daya yang dihasilakan pada pembangkit ini. Dari hasil penelitian didapatkan bahwa prototype Pembangkit Listrik Tenaga Pasang Surut Air Laut menggunakan metode tidal barrage pada ketinggian air pasang maksimum 26 cm dapat membangkitkan arus sebesar 0,068 watt pada saat tidak diberi beban dan 0,061 watt pada saat diberi beban LED 1,7 V dan 30 mA. Didapatkan juga hasil pada panjang saluran air maksimal 20 cm dapat membangkitkan daya sebesar 0,059 watt.

Assessing impacts of tidal power lagoons of a consistent design

Tidal power lagoons have the potential to provide a reliable and long-term source of renewable power. The implementation of tidal lagoons will impact the tidal conditions and hydrodynamics of the surrounding coastal system. Impact assessments in the academic literature have generally investigated working proposals from industry of various shapes and sizes. As such, differences between the impacts arising from considered power plants in varying sites are in part influenced by the individual scheme characteristics, potentially masking the influence of site-specific factors. In this study, scheme design consistency is maintained, providing a basis to focus solely on the merits of the selected locations with regards to any associated impacts. The simulated tidal power lagoons are located in the Bristol Channel and Irish Sea, two distinct but tidally connected regions on the British coastline with contrasting marine environment characteristics. Results indicate that the more constrained geometry of the Bristol Channel contributes to higher individual and cumulative impacts than potential developments in the Irish Sea. This is in part facilitated by the higher degree of blockage introduced by tidal lagoon developments in the Bristol Channel. Furthermore, far-field impacts are found to be less pronounced compared to predictions reported in tidal barrage modelling studies.

Holomorphic Embedding Power Flow Analysis of Hybrid-Tidal-Farm-Integrated Power Distribution System

In this article, a holomorphic embedding power flow model of a hybrid renewable power generating system incorporating onshore tidal barrages and offshore tidal stream turbines is proposed. A doubly fed induction generator is used to harness the electrical power output from the tidal stream turbines, whereas a synchronous generator is used in the tidal barrages. A comparative study of different operating modes for a doubly fed induction generator with a permanent magnet synchronous generator is analyzed for tidal stream turbines based on the variation in the tidal current speed. The proposed power flow method is tested over IEEE 33- and 123-bus benchmark distribution test feeders with a practical 19-bus Indian rural distribution grid and a 132-bus hybrid ac–dc distribution grid. Real-time data of the tidal current speed and the average tidal range are taken for the evaluation of the proposed methodology to show its efficacy over practical distribution networks.

Optimal operation of tidal plants based on nonlinear model predictive control strategy

Tidal range barrage is a well-recognized approach to extract energy from tides in a large scale. Nevertheless, the complexity of tide oscillation poses a challenge to efficaciously regulate this type of plants. Optimization of the process control may result in enhancement of energy yield with low influences on environment. This paper presents a framework where the whole tidal-electric system is modelled and coupled with a nonlinear model predictive control (NMPC) strategy to determine the optimal state of turbo-generators over a complete spring-neap cycle in a month. The method allows the system model to be nonlinear and dynamic under tight constraints, which would be extremely appropriate for the deployment of this highly predictable but frequently varied energy. A potential bay in Norway is chosen to be a proposal site to verify the benefits of the control strategy, by comparing the energy extraction between a simple barrage without sluices and a conventional one with sluices assembly. Results show the conventional barrage type is superior with respect to energy generation, while keeping the turbine blade diameter as as factor. For excessively large turbines, though, the revenue may be curtailed by costs due to environmental factors, and turbine construction.

Glass eel (Anguilla anguilla L.) behaviour after artificial intake by adjusted tidal barrage management

Tidal barrages on water ways constitute a major threat for diadromous fish species such as the critically endangered European eel (Anguilla anguilla L.). An unobstructed migration route between the spawning area in the Sargasso Sea and the freshwater growth habitats in Europe is crucial for the European eels’ long-term survival. Every spring however, millions of glass eels arrive at the European coast to find their inland migration route blocked. Adjusted tidal barrage management (ATBM), i.e. setting the tidal sluice doors ajar during tidal rise, is one of the mitigation measures to enhance glass eel colonisation. Although this management substantially improves the number of incoming glass eels, the fate of these migrants, confronted with abruptly shifting conditions upon sluice passage, remains un-investigated. Glass eel upstream dispersion after sluice passage by means of ATBM was investigated in a drainage canal connecting a small estuary with an adjacent polder area in Belgium. Large numbers of glass eel caught with eel ladders installed at a pumping station about 800 m upstream the tidal barrage indicate that glass eels were well able to switch to an active counter current swimming behaviour to continue upstream dispersion. On the other hand, some glass eels did not initiate active migration but settled in artificial substrates placed in the canal instead. These residents however appeared very successful in using the canal as feeding ground and in time substantially increased their overall fitness. The appearance of both migration strategies (switch to active migration or successful settlement) in this canal shows the potential of ATBM as a valuable tool for the management and restoration of the European eel population and calls for a wide application of this cost-efficient mitigation measure.

Current trends and prospects of tidal energy technology.

Generation of energy across the world is today reliant majorly on fossil fuels. The burning of these fuels is growing in line with the increase in the demand for energy globally. Consequently, climate change, air contamination, and energy security issues are rising as well. An efficient alternative to this grave hazard is the speedy substitution of fossil fuel-based carbon energy sources with the shift to clean sources of renewable energy that cause zero emissions. This needs to happen in conjunction with the continuing increase in the overall consumption of energy worldwide. Many resources of renewable energy are available. These include thermal, solar photovoltaic, biomass and wind, tidal energy, hydropower, and geothermal. Notably, tidal energy exhibits great potential with regard to its dependability, superior energy density, certainty, and durability. The energy mined from the tides on the basis of steady and anticipated vertical movements of the water, causing tidal currents, could be converted into kinetic energy to produce electricity. Tidal barrages could channel mechanical energy, while tidewater river turbines can seize the energy from tidal currents. This study discusses the present trends, ecological effects, and the prospects for technology related to tidal energy.