Tidal energy devices

2015 ◽  
pp. 597-664 ◽  
Keyword(s):  
Tidal Energy ◽  
Energy Devices

scholarly journals Providing ecological context to anthropogenic subsea noise: Assessing listening space reductions of marine mammals from tidal energy devices

2019 ◽  
Vol 103 ◽  
pp. 49-57 ◽  
Author(s):  
Matthew K. Pine ◽  
Pál Schmitt ◽  
Ross M. Culloch ◽  
Lilian Lieber ◽  
Louise T. Kregting
Keyword(s):  
Marine Mammals ◽  
Tidal Energy ◽  
Ecological Context ◽  
Energy Devices

Influence of microstructural defects and hydrostatic pressure on water absorption in composite materials for tidal energy

2018 ◽  
Vol 52 (21) ◽  
pp. 2899-2917 ◽  
Author(s):  
DM Grogan ◽  
M Flanagan ◽  
M Walls ◽  
SB Leen ◽  
A Doyle ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Composite Materials ◽  
Hydrostatic Pressure ◽  
Water Absorption ◽  
Glass Fibre ◽  
Tidal Energy ◽  
Operating Conditions ◽  
X Ray ◽  
Energy Devices ◽  
X Ray Computed

The lifespan and economic viability of tidal energy devices are constrained, in part, by the complex degradation of the tidal turbine blade materials due to prolonged immersion in a hostile sub-sea environment. Seawater penetration is a significant degradation mechanism in composite materials. This work aims to investigate the influence of microstructure and hydrostatic pressure on water absorption in four polymer composites which are candidate materials for use in tidal energy devices. These materials are: a glass fibre powder epoxy, a carbon fibre powder epoxy, glass fibre Ampreg epoxy and a chopped fibre glass fibre Polyether Ether Ketone. X-ray computed tomography is used to characterise the voids, resin-rich areas and other manufacturing defects present in each material. These defects are known to significantly alter the rate of moisture diffusion, as well as the total uptake of water at saturation. The samples are then exposed to accelerated water aging and hydrostatic pressurisation in order to simulate a range of expected sub-sea operating conditions. The material micro-structure, the matrix material and pressurisation level are shown to strongly influence both the moisture absorption rate and total water uptake. Significant volumetric changes are also noted for all samples, both during and after aging. X-ray computed tomography scans of specimens also provide a unique insight into the role of voids in storing water once a material has reached saturation.

scholarly journals Collision risk modelling for tidal energy devices: A flexible simulation-based approach

2021 ◽  
Vol 278 ◽  
pp. 111484
Author(s):  
Nicholas Horne ◽  
Ross M. Culloch ◽  
Pál Schmitt ◽  
Lilian Lieber ◽  
Ben Wilson ◽  
...  
Keyword(s):  
Tidal Energy ◽  
Collision Risk ◽  
Risk Modelling ◽  
Energy Devices ◽  
Simulation Based

Good noise, bad noise: A tricky case of balancing risk of physical injury against acoustic disturbance for marine mammals and tidal energy devices

2017 ◽  
Vol 141 (5) ◽  
pp. 3921-3921
Author(s):  
Ben Wilson ◽  
Brett Marmo ◽  
Paul A. Lepper ◽  
Denise Risch ◽  
Steven Benjamins ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Tidal Energy ◽  
Physical Injury ◽  
Acoustic Disturbance ◽  
Energy Devices

scholarly journals Marine Scour and Offshore Wind: Lessons Learnt and Future Challenges

2011 ◽  
Author(s):  
John M. Harris ◽  
Richard J. S. Whitehouse ◽  
James Sutherland
Keyword(s):  
Hazard Assessment ◽  
Wind Farms ◽  
Tidal Energy ◽  
Offshore Wind ◽  
Commercial Development ◽  
Offshore Wind Farms ◽  
Energy Devices ◽  
Lessons Learnt ◽  
Future Challenges ◽  
Scour Hazard

The drive for developing marine offshore renewables has led to specific requirements for scour hazard assessment relating to the associated foundation structures and the cabling necessary for in-field transmission and power export. To date within the United Kingdom (UK) a number of demonstrator projects have been constructed covering wind, wave and tidal generation. However, only offshore wind has been developed at large-scale at present as part of two rounds of commercial development of offshore wind farms (OWFs). In June 2008, The Crown Estate, responsible for licensing seabed use, announced proposals for a third round of offshore wind farms to develop an additional 25 GW of energy to the 8 GW already planned for under Rounds 1 and 2. The size of these Round 3 developments will vary, but the largest of these zones will involve the construction of around 2500 seabed foundation structures. Under Round 1 and 2 developments monopile and jacket type foundations have been used, although several other European (non UK) wind farms have been built using gravity base foundations. For a wind turbine the foundations may account for up to 35% of the installed cost. Therefore, one of the future challenges for large volume installation of offshore wind is the control and minimization of these costs. For tidal energy devices one of the principal requirements for many of the devices proposed is their placement in areas of strong tidal energy, and this has implications not only for the stability of the foundation option, but also for the construction methodology. Similarly wave energy devices are designed to be located in shallow, coastal environments as either floating or bottom mounted systems. These devices, by design, are intended to be located in environments with strong wave action. This may be substantial during storm events, which has implications for the integrity of the anchoring system keeping the wave device on station or the design of the device if it is seabed mounted. This paper will explore the lessons learnt from existing offshore wind farm developments as this represents the principal body of collected monitoring data. Using these data the paper will outline some of the challenges facing the offshore renewable industry in respect of the foundation designs and specifically the requirements for scour hazard assessment using the combined experience from those developments currently operational or under construction.

Life cycle comparison of a wave and tidal energy device

2011 ◽  
Vol 225 (4) ◽  
pp. 325-337 ◽  
Author(s):  
S Walker ◽  
R Howell
Keyword(s):  
Life Cycle ◽  
Wave Energy ◽  
Tidal Energy ◽  
Development Stage ◽  
Payback Period ◽  
Energy Device ◽  
Energy Mix ◽  
Energy Devices ◽  
Marine Energy ◽  
Marine Current

Tidal and wave energy devices are often discussed as a future contributor to the UK’s energy mix. Indeed, marine energy resources are said to have the potential to supply up to 20 per cent of the nation’s electricity demand. However, these technologies are currently at the development stage and make no meaningful contribution to the national grid. A number of devices have been developed, but no single method has emerged as the leading technology. This paper aims to compare two promising devices, one wave device and one tidal device, and assess the life cycle properties of each. A life cycle assessment of the Oyster wave energy device was conducted as part of this study, and a comparison of this and the SeaGen marine current turbine was undertaken. In both cases a ‘cradle-to-grave’ assessment was carried out, calculating emissions from materials, fabrication, transport, installation, lifetime maintenance, and decommissioning (including recycling). The SeaGen tidal device was calculated to have an energy payback period of 14 months, and a CO2 payback period of 8 months. The equivalent figures for the Oyster device were 12 and 8 months, respectively. The respective energy and carbon intensities for the two devices were 214 kJ/kWh and 15 gCO2/kWh for the SeaGen and 236 kJ/kWh and 25 gCO2/kWh for the Oyster. The calculated intensities and payback periods are close to those of established wind turbine technologies, and low relative to the 400–1000 g CO2/kWh of typical fossil fuel generation. With further developments in construction and deployment efficiency these intensities are expected to fall, so the devices appear to have the potential to offer a viable contribution to the UK’s future energy mix.

scholarly journals Grid Integration of Wave and Tidal Energy

2011 ◽  
Author(s):  
Anne Blavette ◽  
Dara L. O’Sullivan ◽  
Antony W. Lewis ◽  
Michael G. Egan
Keyword(s):  
Wind Energy ◽  
Dynamic Models ◽  
Dynamic Modelling ◽  
Tidal Energy ◽  
Energy Industry ◽  
Grid Integration ◽  
Ocean Energy ◽  
Major Barrier ◽  
Energy Devices ◽  
Grid Connection

Wave and tidal energy provide a renewable source of electricity. However, their inherent fluctuations may have a negative impact on the power quality of a local electrical network. Grid operators assess this impact through the use of dynamic models of the generation units, which are inserted into the overall power system model. Providing these models is a compulsory step for any power generator to procure a grid connection above a specified power capacity. Significant issues were encountered in the wind energy industry regarding the dynamic modelling of devices, among which were model numerical instability, poor dynamic model quality and model incompatibility. Considering the large diversity of device types in the emerging ocean energy industry, these problems are considered as a major barrier to the larger scale grid-integration of marine energy converters. Dynamic models must clearly demonstrate the compliance of the actual power generation device and array of devices to the grid code requirements for grid-connection to be allowed. A further barrier to grid connection of ocean energy devices is that existing grid codes — mainly written in the context of wind energy — may be irrelevant or inadequate for ocean energy devices. This paper presents an overview of these issues, and details a radically different approach to the dynamic modelling of ocean energy devices that will assist in overcoming the issues previously encountered in the development of wind turbine models. It also highlights the gaps and inadequacy regarding grid code requirements for ocean energy devices, and provides some recommendations for a new ocean energy grid code.

Energy Harvesting From the Tidal Currents Using a Mangrove-Like System

2020 ◽  
Author(s):  
Amirkhosro Kazemi ◽  
Oscar Curet ◽  
Daniel Gómez ◽  
Eduardo E. Castillo
Keyword(s):  
Energy Harvesting ◽  
High Speed ◽  
Oscillation Amplitude ◽  
Tidal Energy ◽  
Tidal Currents ◽  
Electric Generator ◽  
Hydrokinetic Energy ◽  
Energy Devices ◽  
Novel Device ◽  
Mangrove Roots

Abstract Tidal energy has the potential for future electricity generation to be widely used in intercostal areas during the rise and fall of tides. Inspired by mangrove roots, we designed a novel device to harvest hydrokinetic energy from tidal currents. This device consists an oscillating cylinder, partially submerged in a flow of water and an electric generator composed of a fixed magnet and a coil attached to the cylinder pivoted at its top by a thin flexible steel plate. This energy harvesting system is considered as one-degree-of-freedom vortex-induced vibration (VIV). The oscillation amplitude of the cylinder tip was recorded with a high-speed camera and 2-D PIV measurements were made to explore the hydrodynamic interaction within the devices for Reynolds numbers ranging from 200 to 1500 (based on cylinder diameter) consistent with biological velocity in tidal flows. We analyzed the kinematics as well as the power generation of the device for different stiffness of the plate. We observed that the cylinder was unmoved for low water velocities; however, by increasing the flow velocity the oscillations increase and reached a maximum value; similar fashion was observed for all stiffness. It was found that for a specific range of reduced velocity (0 < Ur < 3.5) the device worked in its optimal range in which the amplitude of oscillations and the efficacy of the system reach the highest values. This analysis of VIV correlated with oscillations will be fundamental for future bio-inspired energy harvesting devices. These renewable energy devices could have applications to power small actuators or sensors to monitor coastal infrastructure.

scholarly journals Wind-Induced Currents in the Gulf of California from Extreme Events and Their Impact on Tidal Energy Devices

2020 ◽  
Vol 8 (2) ◽  
pp. 80 ◽  
Author(s):  
Markus Gross ◽  
Vanesa Magar
Keyword(s):  
Renewable Energy ◽  
Gulf Of California ◽  
Tidal Energy ◽  
Tidal Range ◽  
Extreme Weather Events ◽  
Worst Case ◽  
Promising Alternative ◽  
Tidal Model ◽  
Energy Devices ◽  
The Impact

Tidal renewable energy is a promising alternative energy resource, and marginal seas are known as excellent sites for tidal energy exploitation. In-stream and tidal energy devices are less exposed to extreme weather events than wind energy. Nevertheless, during tropical storms, the currents may intensify to levels that threaten the integrity of the devices. This paper presents Hurricane Odile and its impact on the currents in the Gulf of California (GC) as a worst case scenario. A methodology to analyze the impact and its potential effects on tidal energy converters installed within the region are presented. The analysis is based on predictions obtained with a 3D shallow water model forced by tides and the meteorological conditions generated by Odile. A tidal model with no wind forcing was used for validation of the tidal model predictions. After validation, the two models were used to analyze the maximum anomaly in surface currents and sea surface height caused by the passage of Odile, and to analyze at which depth the devices could be deemed safe from any impact of the hurricane. Some anomalies extended throughout the water column, even in the deep regions of the GC. This paper highlights the importance of including the meteorological forcing in evaluations of tidal range or in-stream renewable energy resources and introduces new measures of device exposure to the current anomalies.

scholarly journals Epibenthic Assessment of a Renewable Tidal Energy Site

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Emma V. Sheehan ◽  
Sarah C. Gall ◽  
Sophie L. Cousens ◽  
Martin J. Attrill
Keyword(s):  
Renewable Energy ◽  
Global Climate ◽  
Benthic Communities ◽  
Local Environment ◽  
Tidal Energy ◽  
Baseline Survey ◽  
Ecological Data ◽  
Energy Devices ◽  
Potential Control ◽  
Marine Renewable Energy

Concern over global climate change as a result of fossil fuel use has resulted in energy production from renewable sources. Marine renewable energy devices provide clean electricity but can also cause physical disturbance to the local environment. There is a considerable paucity of ecological data at potential marine renewable energy sites that is needed to assess potential future impacts and allow optimal siting of devices. Here, we provide a baseline benthic survey for the Big Russel in Guernsey, UK, a potential site for tidal energy development. To assess the suitability of proposed sites for marine renewable energy in the Big Russel and to identify potential control sites, we compared species assemblages and habitat types. This baseline survey can be used to select control habitats to compare and monitor the benthic communities after installation of the device and contribute towards the optimal siting of any future installation.

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