scholarly journals Effect of tidal stream power generation on the region-wide circulation in a shallow sea

Ocean Science ◽  
2011 ◽  
Vol 7 (1) ◽  
pp. 165-174 ◽  
Author(s):  
G. I. Shapiro
Keyword(s):  
Kinetic Energy ◽  
Energy Resource ◽  
Fold Increase ◽  
Ocean Currents ◽  
Energy Extraction ◽  
Shallow Sea ◽  
Residual Currents ◽  
Tidal Stream ◽  
Generation Capacity ◽  
Extracted Power

Abstract. This paper quantifies the backward effect on the ocean currents caused by a tidal stream farm located in the open shallow sea. Recent studies in channels with 1-D models have indicated that the power potential is not given purely by the flux of kinetic energy, as has been commonly assumed. In this study, a 3-D ocean circulation model is used to estimate (i) practically extractable energy resource at different levels of rated generation capacity of the farm, (ii) changes in the strength of currents due to energy extraction, and (iii) alterations in the pattern of residual currents and the pathways of passive tracers. As well as tidal streams, the model also takes into account the wind-driven and density-driven ocean currents. Numerical modelling has been carried out for a hypothetical tidal farm located in the Celtic Sea north of Cornwall, an area known for its high level of tidal energy. Modelling results clearly indicate that the extracted power does not grow linearly with the increase in the rated capacity of the farm. For the case study covered in this paper, a 100-fold increase in the rated generation capacity of the farm results in only 7-fold increase in extracted power. In the case of a high power farm, kinetic energy of currents is altered significantly as far as 10–20 km away from the farm. At high levels of extracted energy the currents tend to avoid flowing through the farm, an effect which is not captured with 1-D models. Residual currents are altered as far as a hundred kilometres away. The magnitude of changes in the dispersion of tracers is highly sensitive to the location. Some of the passive drifters analysed in this study experience significant variations in the end-to-start distance due to energy extraction ranging from 13% to 238% while others are practically unaffected. This study shows that both energy extraction estimates and effects on region wide circulation depend on a complex combination of factors, and the specific figures given in the paper should be generally considered as first estimates.

scholarly journals Effect of tidal stream power generation on the region-wide circulation in a shallow sea

2010 ◽  
Vol 7 (5) ◽  
pp. 1785-1810 ◽  
Author(s):  
G. I. Shapiro
Keyword(s):  
Kinetic Energy ◽  
Ocean Circulation ◽  
Fold Increase ◽  
Tidal Energy ◽  
Energy Extraction ◽  
Shallow Sea ◽  
Residual Currents ◽  
Tidal Stream ◽  
Generation Capacity ◽  
Extracted Power

Abstract. Ocean tides are deemed to become a stable source of renewable energy for the future. Tidal energy has two components, the first is the potential energy due to sea level variations and the second comes from the kinetic energy of the tidal streams. This paper is concerned with the backward effect on the ocean currents by a tidal stream farm located in the open shallow sea. Recent studies in channels with 1-D models have indicated that the power potential is not given purely by the flux of kinetic energy, as has been commonly assumed. In this study, a 3-D ocean circulation model is used to estimate (i) maximum extractable energy at different levels of rated generation capacity of the farm, (ii) changes in the strength of currents due to energy extraction, and (iii) alterations in the pattern of residual currents and pathways of passive tracers. As water flow is influenced both by tidal and non-tidal currents, the model takes into account wind-driven and density-driven currents generated by meteorological forcing. Numerical modelling has been carried out for a hypothetical circular farm located in the Celtic Sea north of Cornwall, an area known for its high level of tidal energy. Modelling results clearly indicate that extracted power does not grow linearly with the increase in the rated capacity of the farm. For the case studies covered in this paper, a 100-fold increase in rated generation capacity of the farm results only in 7-fold increase in extracted power, this loss of efficiency is much greater than was estimated earlier with 1-D models. In case of high rated capacity of the farm, kinetic energy of currents is altered significantly as far as 10–20 km away from the farm. At high levels of extracted energy the currents tend to avoid flowing through the farm, an effect which is not captured with 1-D models. Residual currents are altered as far as a hundred kilometres. The magnitude of changes in the dispersion of tracers is highly sensitive to the location. For the drifters analysed in this study, variations in the end-to-start distance due to energy extraction range from 13% to 238%.

scholarly journals The influence of waves on the tidal kinetic energy resource at a tidal stream energy site

2016 ◽  
Vol 180 ◽  
pp. 402-415 ◽  
Author(s):  
Nicolas Guillou ◽  
Georges Chapalain ◽  
Simon P. Neill
Keyword(s):  
Kinetic Energy ◽  
Energy Resource ◽  
Tidal Stream ◽  
Tidal Stream Energy

scholarly journals Comparative Effects of Climate Change and Tidal Stream Energy Extraction in a Shelf Sea

2018 ◽  
Vol 123 (7) ◽  
pp. 5041-5067 ◽  
Author(s):  
Michela De Dominicis ◽  
Judith Wolf ◽  
Rory O'Hara Murray
Keyword(s):  
Climate Change ◽  
Energy Extraction ◽  
Shelf Sea ◽  
Tidal Stream ◽  
Tidal Stream Energy

Experimental study on kinetic energy conversion of horizontal axis tidal stream turbine

2016 ◽  
Vol 97 ◽  
pp. 784-797 ◽  
Author(s):  
Jeonghwa Seo ◽  
Seung-Jae Lee ◽  
Woo-Sik Choi ◽  
Sung Taek Park ◽  
Shin Hyung Rhee
Keyword(s):  
Experimental Study ◽  
Kinetic Energy ◽  
Energy Conversion ◽  
Horizontal Axis ◽  
Tidal Stream ◽  
Tidal Stream Turbine

scholarly journals Modeling Assessment of Tidal Energy Extraction in the Western Passage

2020 ◽  
Vol 8 (6) ◽  
pp. 411
Author(s):  
Zhaoqing Yang ◽  
Taiping Wang ◽  
Ziyu Xiao ◽  
Levi Kilcher ◽  
Kevin Haas ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Three Dimensional ◽  
Energy Resource ◽  
Field Measurements ◽  
Tidal Energy ◽  
Resource Assessment ◽  
Ocean Model ◽  
Energy Extraction ◽  
Technical Specifications

Numerical models have been widely used for the resource characterization and assessment of tidal instream energy. The accurate assessment of tidal stream energy resources at a feasibility or project-design scale requires detailed hydrodynamic model simulations or high-quality field measurements. This study applied a three-dimensional finite-volume community ocean model (FVCOM) to simulate the tidal hydrodynamics in the Passamaquoddy–Cobscook Bay archipelago, with a focus on the Western Passage, to assist tidal energy resource assessment. IEC Technical specifications were considered in the model configurations and simulations. The model was calibrated and validated with field measurements. Energy fluxes and power densities along selected cross sections were calculated to evaluate the feasibility of the tidal energy development at several hotspots that feature strong currents. When taking both the high current speed and water depth into account, the model results showed that the Western Passage has great potential for the deployment of tidal energy farms. The maximum extractable power in the Western Passage was estimated using the Garrett and Cummins method. Different criteria and methods recommended by the IEC for resource characterization were evaluated and discussed using a sensitivity analysis of energy extraction for a hypothetical tidal turbine farm in the Western Passage.

A comparison of residual currents estimated with current meters and a parachute drogue in a shallow sea

1978 ◽  
Vol 31 (6) ◽  
pp. 237-248 ◽  
Author(s):  
David A. Booth ◽  
Michael J. Howarth ◽  
Joseph A. Durance ◽  
John H. Simpson
Keyword(s):  
Shallow Sea ◽  
Residual Currents

Effects on hydrodynamics and ecological costs of climate change and tidal stream energy extraction in a shelf sea

2020 ◽  
Author(s):  
Michela De Dominicis ◽  
Judith Wolf ◽  
Dina Sadykova ◽  
Beth Scott ◽  
Alexander Sadykov ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climate Scenario ◽  
Tidal Energy ◽  
Ocean Model ◽  
Future Climate ◽  
Biogeochemical Model ◽  
Energy Extraction ◽  
Shelf Sea ◽  
Tidal Stream

<p>The aim of this work is to analyse the potential impacts of tidal energy extraction on the marine environment. We wanted to put them in the broader context of the possibly greater and global ecological threat of climate change. Here, we present how very large (hypothetical) tidal stream arrays and a ''business as usual'' future climate scenario can change the hydrodynamics of a seasonally stratified shelf sea, and consequently modify ecosystem habitats and animals’ behaviour.</p><p>The Scottish Shelf Model, an unstructured grid three-dimensional ocean model, has been used to reproduce the present and the future state of the NW European continental shelf. While the marine biogeochemical model ERSEM (European Regional Seas Ecosystem Model) has been used to describe the corresponding biogeochemical conditions. Four scenarios have been modelled: present conditions and projected future climate in 2050, each with and without very large scale tidal stream arrays in Scottish Waters (UK). This allows us to evaluate the potential effect of climate change and large scale energy extraction on the hydrodynamics and biogeochemistry. We found that climate change and tidal energy extraction both act in the same direction, in terms of increasing stratification due to warming and reduced mixing, however, the effect of climate change is ten times larger. Additionally, the ecological costs and benefits of these contrasting pressures on mobile predator and prey marine species are evaluated using ecological statistical models.</p>

scholarly journals Effect of waves on the tidal energy resource at a planned tidal stream array

2015 ◽  
Vol 75 ◽  
pp. 626-639 ◽  
Author(s):  
M. Reza Hashemi ◽  
Simon P. Neill ◽  
Peter E. Robins ◽  
Alan G. Davies ◽  
Matt J. Lewis
Keyword(s):  
Energy Resource ◽  
Tidal Energy ◽  
Tidal Stream
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