Assessment of Zooplankton Injury and Mortality Associated With Underwater Turbines for Tidal Energy Production

2013 ◽  
Vol 47 (4) ◽  
pp. 142-150 ◽  
Author(s):  
David R. Schlezinger ◽  
Craig D. Taylor ◽  
Brian L. Howes
Keyword(s):  
Size Distribution ◽  
Particle Density ◽  
Collaborative Work ◽  
Tidal Energy ◽  
Energy Potential ◽  
Marine Renewable Energy ◽  
Tidal Turbines ◽  
Video Images ◽  
Significant Difference ◽  
Tidal Turbine

AbstractCollaborative work between the UMASS-Marine Renewable Energy Center, the Town of Edgartown, and the Coastal Systems Program is focused on developing the tidal energy potential of Muskeget Channel. We have undertaken detailed oceanographic and environmental surveys to optimize in-stream turbine power generation and to quantify potential environmental effects. In 2011 and 2012, tidal turbine demonstration projects were conducted in Muskeget Channel to determine the combined effects of blade strikes, shear stress, turbulence, and cavitation on zooplankton. Single turbines may minimally impact zooplankton populations; however, full-scale projects may potentially alter zooplankton populations forming the base of coastal food webs. Static plankton tows were performed up- and downstream of the operating turbine axis. Integral flow meters allowed adjustment of tow duration to optimize zooplankton density in the concentrate. Samples were held at in situ temperatures, and sequential photomicrographs and video images were taken to determine particle density, size distribution, and the number of live organisms in samples taken up and down gradient of the operating tidal turbines within 3 h of collection. Statistical analysis showed no significant difference in the total number or size distribution of motile zooplankters, indicating tidal turbine operation did not cause significant mortality and suggested that impacts of commercial size tidal energy projects upon zooplankton populations in Muskeget Channel may be negligible.

scholarly journals Passive acoustic methods for tracking the 3D movements of small cetaceans around marine structures

2020 ◽  
Author(s):  
Douglas Gillespie ◽  
Laura Palmer ◽  
Jamie Macaulay ◽  
Carol Sparling ◽  
Gordon Hastie
Keyword(s):  
Marine Mammals ◽  
New Technologies ◽  
Three Dimensional ◽  
Tidal Energy ◽  
Time Of Arrival ◽  
Marine Animals ◽  
Tidal Turbines ◽  
Wide Range ◽  
Tidal Turbine ◽  
Passive Acoustic

AbstractA wide range of anthropogenic structures exist in the marine environment with the extent of these set to increase as the global offshore renewable energy industry grows. Many of these pose acute risks to marine wildlife; for example, tidal energy generators have the potential to injure or kill seals and small cetaceans through collisions with moving turbine parts. Information on fine scale behaviour of animals close to operational turbines is required to understand the likely impact of these new technologies. There are inherent challenges associated with measuring the underwater movements of marine animals which have, so far, limited data collection. Here, we describe the development and application of a system for monitoring the three-dimensional movements of cetaceans in the immediate vicinity of a subsea structure. The system comprises twelve hydrophones and software for the detection and localisation of vocal marine mammals. We present data demonstrating the systems practical performance during a deployment on an operational tidal turbine between October 2017 and October 2019. Three-dimensional locations of cetaceans were derived from the passive acoustic data using time of arrival differences on each hydrophone. Localisation accuracy was assessed with an artificial sound source at known locations and a refined method of error estimation is presented. Calibration trials show that the system can accurately localise sounds to 2m accuracy within 20m of the turbine but that localisations become highly inaccurate at distances greater than 35m. The system is currently being used to provide data on rates of encounters between cetaceans and the turbine and to provide high resolution tracking data for animals close to the turbine. These data can be used to inform stakeholders and regulators on the likely impact of tidal turbines on cetaceans.

Exploring the Effect of Length and Angle on NACA 0010 for Diffuser Design in Tidal Current Turbines

2012 ◽  
Vol 201-202 ◽  
pp. 438-441 ◽  
Author(s):  
Nasir Mehmood ◽  
Liang Zhang ◽  
Jawad Khan
Keyword(s):  
Kinetic Energy ◽  
Tidal Current ◽  
Current Flow ◽  
Tidal Energy ◽  
Research Community ◽  
Financial Resources ◽  
Considerable Time ◽  
Tidal Turbines ◽  
Tidal Turbine

Tidal energy is one of the most predictable forms of renewable energy.Tides posses both potential and kinetic energy. Tidal energy can be utilized by capturing potential energy i.e. by means of tidal barrage and tidal fence or by capturing kinetic energy i.e. by menas of tidal current technologies. This study is focused on diffuser augmented tidal turbines that capture the kinetic energy. The power generated by a tidal turbine is directly proportional to the cube of velocity of current flow. The role of the diffuser in diffuser augmented tidal turbines is to help accelerate the incoming current velocity. Consequently, the efficiency of the turbine is significantly increasedby using adiffuser. The research community is investing considerable time and financial resources in thisgrowingdomain. The diffuser augmented tidal turbinesresearch datais rather scarce due to their emerging nature, large and costly research & development setup, startup cost and proprietary issues. The purpose of this paper is to study the effect of length and angle on NACA 0010airfoil for diffuser design. Numerical simulation is carried out to investigate velocity and mass flow rate at the throat. The drag force due to diffuser installation is also calculated.

Tidal Turbine Blade Selection for Optimal Performance in an Array

2011 ◽  
Author(s):  
Rachel F. Nicholls-Lee ◽  
Stephen R. Turnock ◽  
Stephen W. Boyd
Keyword(s):  
Tidal Cycle ◽  
Free Stream ◽  
Stokes Equations ◽  
Tidal Energy ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Energy Capture ◽  
Tidal Turbines ◽  
Outer Domain ◽  
Tidal Turbine

In order to maximize tidal energy capture from a specific site free stream devices are situated in arrays. In an array the downstream evolution of the wake generated by a rotating tidal energy conversion device influences the performance of the device itself, the bypass flow to either side as well as the performance of any downstream device. As such it is important to design a turbine that can perform efficiently and effectively in these circumstances. Use of passively adaptive composite blades for horizontal axis tidal turbines has been shown to improve performance in fluctuating inflows. Active adaptation and/or bi-directional hydrofoil sections could be implemented in order to optimize performance throughout the tidal cycle. This paper considers the performance in an array of four free stream turbines implementing standard rigid blades, wholly bidirectional blades, passively adaptive blades and actively adaptive blades. The method used to evaluate the performance of tidal current turbines in arrays couples an inner domain solution of the blade element momentum theory with an outer domain solution of the Reynolds averaged Navier Stokes equations. The annual energy capture of four devices with each blade type in a staggered array is then calculated for a single tidal cycle and compared.

scholarly journals 3D Simulation with Flow-Induced Rotation for Non-Deformable Tidal Turbines

2021 ◽  
Vol 9 (3) ◽  
pp. 250
Author(s):  
Ilan Robin ◽  
Anne-Claire Bennis ◽  
Jean-Claude Dauvin
Keyword(s):  
Vertical Axis ◽  
Tidal Energy ◽  
Fluid Structure Interactions ◽  
Good Correspondence ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Correct Direction ◽  
Convergence Study ◽  
Vertical Axis Tidal Turbine ◽  
Mesh Convergence

The overall potential for recoverable tidal energy depends partly on the tidal turbine technologies used. One of problematic points is the minimum flow velocity required to set the rotor into motion. The novelty of the paper is the setup of an innovative method to model the fluid–structure interactions on tidal turbines. The first part of this work aimed at validating the numerical model for classical cases of rotation (forced rotation), in particular, with the help of a mesh convergence study. Once the model was independent from the mesh, the numerical results were tested against experimental data for both vertical and horizontal tidal turbines. The results show that a good correspondence for power and drag coefficients was observed. In the wake, the vortexes were well captured. Then, the fluid drive code was implemented. The results correspond to the expected physical behavior. Both turbines rotated in the correct direction with a coherent acceleration. This study shows the fundamental operating differences between a horizontal and a vertical axis tidal turbine. The lack of experiments with the free rotation speed of the tidal turbines is a limitation, and a digital brake could be implemented to overcome this difficulty.

scholarly journals Study of Hydrodynamic Interference of Vertical-Axis Tidal Turbine Array

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1228
Author(s):  
Guangnian Li ◽  
Qingren Chen ◽  
Hanbin Gu
Keyword(s):  
Vertical Axis ◽  
Tidal Energy ◽  
Element Model ◽  
Hydrodynamic Performance ◽  
Maximum Efficiency ◽  
Hydrodynamic Characteristics ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
Vertical Axis Turbine ◽  
Vertical Axis Tidal Turbine

The hydrodynamic interference between tidal turbines must be considered when predicting their overall hydrodynamic performance and optimizing the layout of the turbine array. These factors are of great significance to the development and application of tidal energy. In this paper, the phenomenon of hydrodynamic interference of the tidal turbine array is studied by the hydrodynamic performance forecast program based on an unsteady boundary element model for the vertical-axis turbine array. By changing the relative positions of two turbines in the double turbine array to simulate the arrangement of different turbines, the hydrodynamic interference law between the turbines in the array and the influence of relative positions on the hydrodynamic characteristics in the turbine array are explored. The manner in which the turbines impact each other, the degree of influence, and rules for turbine array arrangement for maximum efficiency of the array will be discussed. The results of this study will provide technical insights to relevant researchers.

scholarly journals Estimating the stability of a bed protection of a weir-mounted tidal turbine

2020 ◽  
Vol 3 (1) ◽  
pp. 21-24
Author(s):  
Merel C. Verbeek ◽  
Robert J. Labeur ◽  
Wim S. J. Uijttewaal
Keyword(s):  
Tidal Energy ◽  
Potential Effect ◽  
Flow Recirculation ◽  
Tidal Turbines ◽  
Sea Bed ◽  
Tidal Turbine ◽  
The Stability ◽  
Hydrodynamic Data ◽  
Bed Protection ◽  
Horizontal Axis Turbine

Coastal infrastructure, such as bridges and storm surge barriers with weirs, provides an attractive location for harvesting renewable energy using tidal turbines. Often stone layers are applied downstream of coastal infrastructure to protect the sea bed from erosion. However, little is known about the potential effect of tidal energy extraction on the stability of this granular bed protection. This paper describes a study of the flow conditions influencing the stability of the bed protection downstream of a weir-mounted tidal turbine, using hydrodynamic data of an experimental test. The analysis indicates that the flow recirculation zone downstream of a weir may become shorter and flatter due to the presence of a horizontal-axis turbine. As a result, energetic turbulence eddies can transport more horizontal momentum towards the bed – hence the reason a heavier bed protection may be required for granular beds downstream of weirs when a turbine is installed. This information is essential when designing safe bed protections for coastal infrastructure with tidal turbines.

Durability of Polymers and Composites: The Key to Reliable Marine Renewable Energy Production

2018 ◽  
Author(s):  
Peter Davies ◽  
Pierre-Yves Le Gac ◽  
Maelenn Le Gall ◽  
Mael Arhant ◽  
Corentin Humeau
Keyword(s):  
Renewable Energy ◽  
Turbine Blades ◽  
Fatigue Tests ◽  
Synthetic Fiber ◽  
Marine Renewable Energy ◽  
Tidal Turbines ◽  
Marine Energy ◽  
Influence Of Water ◽  
Tidal Turbine ◽  
Significant Cost Reduction

Recovery of marine energy is progressing from the prototype stage to arrays, and all of the systems currently being developed include critical elements manufactured from polymers and composites. Structural MRE (Marine Renewable Energy) components range from composite turbine blades, for floating wind and tidal turbines, to polymer fiber ropes for wave, tidal and floating wind mooring systems. Elastomeric components are also widely used for sealing and protection. In all cases it is essential to understand how seawater diffuses into these polymers and how it affects mechanical properties; this allows appropriate safety factors to be applied without excessive over-conservative design, and can result in significant cost reduction. This paper will present a methodology for evaluating the long term behavior of such components based on accelerated testing. Three examples will be shown to illustrate the approach; tidal turbine blade composites, synthetic fiber rope moorings, and rubber components. In each case the seawater diffusion kinetics will be described first, then the influence of water on mechanical behavior will be quantified for the particular loadings of interest, and finally results from fully coupled fatigue tests in seawater will be discussed.

The Development of a Risk-Based Guideline for the Design of Current and Tidal Turbines

2015 ◽  
Author(s):  
Laura-Mae Macadré ◽  
Stéphane Paboeuf ◽  
Nicolas Dietenbeck ◽  
Stéphane le Diraison
Keyword(s):  
Wind Energy ◽  
New Technology ◽  
Tidal Energy ◽  
Certification Process ◽  
Guidance Note ◽  
Tidal Turbines ◽  
Wide Range ◽  
Tidal Turbine ◽  
Certification Type ◽  
Offshore Oil

Tidal turbines are emerging technologies offering a great potential by the harnessing of a renewable and predictable resource. However, exploitation at sea comes with significant design, installation, grid connection, and maintenance operations challenges. Consequently, guidelines and standards are required to ensure safety, reliability and quality for these innovative technologies, to support designers and to accelerate the development and commercialisation of the tidal technology. As tidal energy concepts are only at the demonstration stage, only few standards have been published about tidal and current turbines and no dedicated certification procedures have been developed so far. The aim of this paper is to present a risk-based certification process developed by Bureau Veritas for tidal turbines and published in the Guidance Note NI603 Current and Tidal Turbines. Based on experience accumulated over the past years with tidal turbines technology developers, typical challenges related to the design and installation of tidal devices at sea will be highlighted in this paper. To support tidal turbines designers to take up these challenges, Bureau Veritas provides a decision-making guide gathering 1) recommendations from the existing experience at sea of tidal devices, 2) best practices from related sectors, such as shipping, wind energy or offshore oil & gas, 3) a risk-based approach to consider for the particular requirements of each tidal turbine installation. In particular for tidal turbines, projects are highly site specific with huge impacts on farm layouts and foundation designs, to name but a few of the issues to be addressed. Paradoxically, the aim of certification societies is to develop rules and tools that can be applicable to a wide range of designs. Consequently, trying not to be design-specific, a proposal of a generic certification process is made in this paper. Existing certification principles from more mature sectors such as wind energy, offshore oil & gas or shipping have been adapted to the specificities of tidal turbines. This paper addresses different certification procedures such as prototype certification, component certification, type certification and project certification. Their respective application and interactions are developed, with a focus on prototype and type certification. In addition, particular attention is paid to the novelty induced by tidal turbines. Consequently, a risk-based guidance is provided to use qualification of new technology for the most innovative parts of the tidal device.

Power Performance Assessment of the Tidal Turbine Sabella D10 Following IEC62600-200

2016 ◽  
Author(s):  
Stéphane Paboeuf ◽  
Pascal Yen Kai Sun ◽  
Laura-Mae Macadré ◽  
Gaël Malgorn
Keyword(s):  
Performance Assessment ◽  
Technical Specification ◽  
Tidal Energy ◽  
Electrical Network ◽  
Power Performance ◽  
Electricity Grid ◽  
Tidal Turbines ◽  
Site Characteristics ◽  
Tidal Turbine ◽  
Power Curves

Recently, the tidal turbine Sabella D10 has been installed in the Fromveur Passage, off Ushant Island, in France. Sabella D10 is a 1 MW tidal turbine fully submerged and laid on the seabed with a horizontal axis and 6 blades. It is the first French tidal turbine producing electricity and connected to the electrical network. As tidal turbines are emerging technologies, the demonstration of the power performance in real conditions is vital for designers. Currently, few full scale prototypes have been tested at sea and even less have been integrated into the electricity grid. Due to this context, the standard IEC62600-200 Electricity producing tidal energy converter - power performance assessment has been applied only on a limited number of turbines and, as a consequence, industrials have a limited feedback on the use of the IEC62600-200. The aim of this paper is to detail the IEC62600-200 requirements for the power performance assessment, and the application case on the tidal turbine Sabella D10. The technical specification IEC62600-200 was issued in 2013 and describes the procedure for the power performance assessment of the tidal converters. This technical specification gives requirements for the site and test conditions, the measurement procedures and their exploitation to obtain the power curves. Finally, the reporting format of the results, is detailed to provide a complete document to the certification body. In the framework of the project Sabella D10, funded by ADEME, the power curves of the tidal turbine prototype D10 of Sabella have been established in cooperation with Sabella and Bureau Veritas according to IEC62600-200. They worked together for the interpretation of the technical specification, the exploitation of the measurements and the presentation of the results. The global procedure of IEC has been followed however some adaptations have been made to take into account the Sabella D10 specifics and site characteristics. Indeed, the Sabella D10 project started before the IEC62600-200 publication and some requirements have not been anticipated at the beginning of the project. The first objective of this analysis is to challenge the IEC methodology with an analysis of a real set of production data and to demonstrate the applicability of the technical specification. Additionally, the assumptions and the deviation with the IEC will be presented and some improvements of the standard will be proposed in conclusion.

scholarly journals Tidal Energy Utilization of Larantuka Strait by Dual Tidal Turbines to Increase National Energy Resilience

2019 ◽  
Vol 2 ◽  
pp. 73-77
Author(s):  
Eko Soejianto ◽  
Khansa Hanifa Zahra ◽  
Suci Nur Hidayah
Keyword(s):  
Renewable Energy ◽  
Energy Demand ◽  
Energy Resource ◽  
Electrical Energy ◽  
Tidal Energy ◽  
Ocean Currents ◽  
Energy Utilization ◽  
Tidal Turbines ◽  
Tidal Turbine ◽  
The Government

Currently, renewable energy can only support 5% of national energy needs. Meanwhile, in 2035 renewable energy targeted to sustain 14% of total national energy demand. The proper way for optimizing the renewable energy is needed to actualize the target. Tidal energy as one of the potentials that are still being developed and need more attention from the government. Tidal can be used for natural energy resource since it has zero emission, produce big energy, and has no impact to weather. Larantuka Strait located in Flores island, Nusa Tenggara Timur province can produce tidal velocity up to 2.859 m/s with water density as much as 1.025 gr/cc.  In utilizing this energy, we use new innovation by using dual tidal turbines which placed at the foot of Palmerah Bridge. The construction of Palmerah Bridge is built both by the government of Flores Island and Adonara Island. Dual tidal turbines are more efficient than singl e turbine by reason of tidal that has passed through the first turbine can be used again for the second turbine. The using of the generator is meant to convert kinetic energy that produced by dual tidal turbines. To convert ocean currents into electrical energy optimally, it is necessary to plan turbine designs that are in accordance with the conditions of ocean currents and the surrounding environment such as current velocity, wind influences and so on. Horizontal-axis tidal turbine (HATTs) is one of the technologies that are being developed and tested in prototype form by several companies, an efficient blade design is very important for the success of the HATTs. The amount of turbine needs, in this case, is 15 turbines with each turbine’s length is 10 meters. The turbines installed in bridge’s column along 800 meters. Estimate electricity can be generated by the turbine is 1.48 Mega Watt (MW).

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