Tidal energy resource assessment for tidal stream generators

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.

Download Full-text

Investigation of the Modulation of the Tidal Stream Resource by Ocean Currents through a Complex Tidal Channel

Journal of Marine Science and Engineering ◽

10.3390/jmse7100341 ◽

2019 ◽

Vol 7 (10) ◽

pp. 341 ◽

Cited By ~ 3

Author(s):

Alice J. Goward Brown ◽

Matt Lewis ◽

Benjamin I. Barton ◽

Gus Jeans ◽

Steven A. Spall

Keyword(s):

Tidal Energy ◽

Resource Assessment ◽

Tidal Currents ◽

The West ◽

Ocean Modelling ◽

Through Flow ◽

The World ◽

Tidal Stream ◽

Flow Through ◽

Resource Uncertainty

Tidal energy has the opportunity to bring reliable electricity to remote regions in the world. A resource assessment, including the response of the tidal stream resource to fluctuations in the Indonesian Through Flow (ITF) is performed using the Regional Ocean Modelling System (ROMS) to simulate four different scenarios for flow through the Lombok Strait in Indonesia. Tidal currents simulated with a variable ITF are compared against a tide-only (TO) simulation to identify how the ITF spatially changes the resource across the Lombok Strait. We find that the uncertainty in the tidal currents from the TO simulation is 50% greater than the variable ITF simulation. To identify change to resource, surface velocities from Strong ITF and Weak ITF scenarios are considered. As a result of the fluctuations in the ITF, certain characteristics, such as the asymmetry and magnitude, of the tidal current vary greatly. However, the magnitude of change is variable, with regions to the west of the strait experiencing greater modulation than in the east, suggesting that resource uncertainty can be minimised with selective site positioning.

Download Full-text

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

Renewable Energy ◽

10.1016/j.renene.2014.10.029 ◽

2015 ◽

Vol 75 ◽

pp. 626-639 ◽

Cited By ~ 47

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

Download Full-text

Bardsey – an island in a strong tidal stream: underestimating coastal tides due to unresolved topography

Ocean Science ◽

10.5194/os-16-1337-2020 ◽

2020 ◽

Vol 16 (6) ◽

pp. 1337-1345

Author(s):

J. A. Mattias Green ◽

David T. Pugh

Keyword(s):

Satellite Altimetry ◽

Energy Resource ◽

Tidal Energy ◽

Small Scale ◽

Phase Lag ◽

Wake Effect ◽

Tidal Dissipation ◽

Tidal Energetics ◽

Tidal Stream ◽

Tidal Streams

Abstract. Bardsey Island is located at the western end of the Llŷn Peninsula in northwestern Wales. Separated from the mainland by a channel that is some 3 km wide, it is surrounded by reversing tidal streams of up to 4 m s−1 during spring tides. These local hydrodynamic details and their consequences are unresolved by satellite altimetry and are not represented in regional tidal models. Here we look at the effects of the island on the strong tidal stream in terms of the budgets for tidal energy dissipation and the formation and shedding of eddies. We show, using local observations and a satellite-altimetry-constrained product (TPXO9), that the island has a large impact on the tidal stream and that even in this latest altimetry-constrained product the derived tidal stream is under-represented due to the island not being resolved. The effect of the island leads to an underestimate of the current speed in the TPXO9 data in the channel of up to a factor of 2.5, depending on the timing in the spring–neap cycle, and the average tidal energy resource is underestimated by a factor up to 14. The observed tidal amplitudes are higher at the mainland than at the island, and there is a detectable phase lag in the tide across the island; this effect is not seen in the TPXO9 data. The underestimate of the tide in the TPXO9 data has consequences for tidal dissipation and wake effect computation and shows that local observations are key to correctly estimating tidal energetics around small-scale coastal topography.

Download Full-text

Numerical modelling of hydrodynamics and tidal energy extraction in the Alderney Race: a review

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0498 ◽

2020 ◽

Vol 378 (2178) ◽

pp. 20190498

Author(s):

Jérôme Thiébot ◽

D. S. Coles ◽

Anne-Claire Bennis ◽

Nicolas Guillou ◽

Simon Neill ◽

...

Keyword(s):

Numerical Modelling ◽

Three Dimensional ◽

Energy Resource ◽

Tidal Energy ◽

Resource Assessment ◽

Spatial Modelling ◽

Optimization Techniques ◽

Energy Extraction ◽

Model Case ◽

Eddy Simulation

The tides are a predictable, renewable, source of energy that, if harnessed, can provide significant levels of electricity generation. The Alderney Race (AR), with current speeds that exceed 5 m s −1 during spring tides, is one of the most concentrated regions of tidal energy in the world, with the upper-bound resource estimated at 5.1 GW. Owing to its significance, the AR is frequently used for model case studies of tidal energy conversion, and here we review these model applications and outcomes. We examine a range of temporal and spatial modelling scales, from regional models applied to resource assessment and characterization, to more detailed models that include energy extraction and array optimization. We also examine a range of physical processes that influence the tidal energy resource, including the role of waves and turbulence in tidal energy resource assessment and loadings on turbines. The review discusses model validation, and covers a range of numerical modelling approaches, from two-dimensional to three-dimensional tidal models, two-way coupled wave-tide models, Large Eddy Simulation (LES) models, and the application of optimization techniques. The review contains guidance on model approaches and sources of data that can be used for future studies of the AR, or translated to other tidal energy regions. This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.

Download Full-text

The Tidal Stream Energy Resource of the Fromveur Strait—A Review

Journal of Marine Science and Engineering ◽

10.3390/jmse8121037 ◽

2020 ◽

Vol 8 (12) ◽

pp. 1037

Author(s):

Nicolas Guillou ◽

Jean-Frédéric Charpentier ◽

Mohamed Benbouzid

Keyword(s):

Energy Resource ◽

Tidal Energy ◽

Energy Output ◽

Wake Interactions ◽

Tidal Stream ◽

Technical Specifications ◽

Tidal Stream Energy ◽

Key Steps ◽

A Site

Refined assessments of the available tidal stream energy resource are required to optimize turbines design and guarantee successful implementations and operations of devices in the marine environment. Investigations primary focused on identifying areas with maximum current speeds. However, further information may be reached by exhibiting (i) resource temporal variability, (ii) superimposed effects of meteo-oceanographic conditions (including especially wind-generated surface-gravity waves), and (iii) potential environmental impacts of operating turbines at the regional (e.g., changes in sediment transport and surrounding seabed features, effects on marine water quality, etc.) and local (wake-wake interactions and energy output) scales. These aspects are here investigated by reviewing a series of research studies dedicated to the Fromveur Strait off western Brittany, a region with strong potential for tidal array development along the coast of France. Particular attention is dedicated to the exploitation of combined in-situ and remote-sensing observations and numerical simulations. Beyond a site specific characterization of the tidal stream energy resource, this review promotes a series of original approaches and analysis methods for turbines optimization, thus complementing technical specifications to secure the key steps of a tidal energy project and promote the growth of a reliable tidal stream energy exploitation.

Download Full-text

Wave and tidal energy resource assessment in Uruguayan shelf seas

Renewable Energy ◽

10.1016/j.renene.2017.03.074 ◽

2017 ◽

Vol 114 ◽

pp. 18-31 ◽

Cited By ~ 14

Author(s):

Rodrigo Alonso ◽

Michelle Jackson ◽

Pablo Santoro ◽

Mónica Fossati ◽

Sebastián Solari ◽

...

Keyword(s):

Energy Resource ◽

Tidal Energy ◽

Resource Assessment ◽

Shelf Seas

Download Full-text

Effects of CFD parameter variation on Tidal Energy Resource Assessment

TENCON 2012 IEEE Region 10 Conference ◽

10.1109/tencon.2012.6412225 ◽

2012 ◽

Cited By ~ 1

Author(s):

Michael Lochinvar Sim Abundo ◽

Chew Kok Hon ◽

Martin Koh Wei Xiang ◽

Oh Boon Kiat ◽

Wilbur Tan Hong Huat

Keyword(s):

Energy Resource ◽

Tidal Energy ◽

Resource Assessment ◽

Parameter Variation

Download Full-text

Spatio-temporal variability of tidal-stream energy in north-western Europe

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2019.0493 ◽

2020 ◽

Vol 378 (2178) ◽

pp. 20190493 ◽

Cited By ~ 1

Author(s):

Nicolas Guillou ◽

Simon P. Neill ◽

Jérôme Thiébot

Keyword(s):

Temporal Variability ◽

Western Europe ◽

Energy Resource ◽

Phase Relationship ◽

Tidal Energy ◽

The North ◽

Tidal Stream ◽

Tidal Stream Energy ◽

Spatio Temporal ◽

North Western

Initial selection of tidal stream energy sites is primarily based on identifying areas with the maximum current speeds. However, optimal design and deployment of turbines requires detailed investigations of the temporal variability of the available resource, focusing on areas with reduced variability, and hence the potential for more continuous energy supply. These aspects are investigated here for some of the most promising sites for tidal array development across the north-western European shelf seas: the Alderney Race, the Fromveur Strait, the Pentland Firth and the channels of Orkney. Particular attention was dedicated to asymmetry between the flood and ebb phases of the tidal cycle (due to the phase relationship between M 2 and M 4 constituents), and spring-neap variability of the available resource (due to M 2 and S 2 compound tides). A series of high-resolution models were exploited to (i) produce a detailed harmonic database of these three components, and (ii) characterize, using energy resource metrics, temporal variability of the available power density. There was a clear contrast between the Alderney Race, with reduced temporal variability over semi-diurnal and fortnightly time scales, and sites in western Brittany and North Scotland which, due to increased variability, appeared less attractive for optimal energy conversion. This article is part of the theme issue ‘New insights on tidal dynamics and tidal energy harvesting in the Alderney Race’.

Download Full-text