Tidal stream energy resource assessment in the Qiantang River Estuary, China

A novel method for modelling tidal-stream energy capture at the regional scale is used to evaluate the performance of two marine turbine arrays configured as a fence and a partial fence. These configurations were used to study bounded and unbounded flow scenarios, respectively. The method implemented uses turbine operating conditions (TOC) and the parametrisation of changes produced by power extraction within the turbine near-field to compute a non-constant thrust coefficient, and it is referred to as a momentum sink TOC. Additionally, the effects of using a shock-capture capability to evaluate the resource are studied by comparing the performance of a gradually varying flow (GVF) and a rapidly varying flow (RVF) solver. Tidal-stream energy assessment of bounded flow scenarios through a full fence configuration is better performed using a GVF solver, because the head drop is more accurately simulated; however, the solver underestimates velocity reductions due to power extraction. On the other hand, assessment of unbounded flow scenarios through a partial fence was better performed by the RVF solver. This scheme approximated the head drop and velocity reduction more accurately, thus suggesting that resource assessment with realistic turbine configurations requires the correct solution of the discontinuities produced in the tidal-stream by power extraction.

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

Applied Energy ◽

10.1016/j.apenergy.2016.07.070 ◽

2016 ◽

Vol 180 ◽

pp. 402-415 ◽

Cited By ~ 32

Author(s):

Nicolas Guillou ◽

Georges Chapalain ◽

Simon P. Neill

Keyword(s):

Kinetic Energy ◽

Energy Resource ◽

Tidal Stream ◽

Tidal Stream Energy

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The value of tidal-stream energy resource to off-grid communities

10.5194/egusphere-egu2020-2747 ◽

2020 ◽

Author(s):

Matt Lewis ◽

John Maskell ◽

Daniel Coles ◽

Michael Ridgill ◽

Simon Neill

Keyword(s):

Energy Resource ◽

Distribution Networks ◽

Ocean Model ◽

Offshore Wind ◽

Published Data ◽

Electricity Supply ◽

Power Curve ◽

Mean Flow ◽

Tidal Stream ◽

Tidal Stream Energy

<p>Tidal-stream energy research has often focused on the applicability of the resource to large electricity distribution networks, or reducing costs so it can compete with other renewables (such as offshore wind). Here we explore how tidal electricity may be worth the additional cost, as the quality and predictability of the electricity could be advantageous &#8211; especially to remote &#8220;off-grid&#8221; communities and industry.</p><p>The regular motion from astronomical forces allows the tide to be predicted far into the future, and therefore idealised scenarios of phasing tidal electricity supply to demand can be explored. A normalised tidal-stream turbine power curve, developed from published data on 15 devices, was developed. Tidal harmonics of a region, based on ocean model output, were used in conjunction with this normalised tidal-stream power curve, and predictions of yield and the timing of electricity supply were made. Such analysis allows the type and number of turbines needed for a specific community requirement, as well as a resource-led tidal turbine optimisation for a region. For example, with a simple M2 tide (12.42hour period) of 2m/s peak flow, which represents mean flow conditions, a rated turbine speed of 1.8m/s gives the highest yield-density of all likely turbine configurations (i.e. calculated from power density and so ignores turbine diameter), and with a 41% Capacity Factor. Furthermore, as tidal current and power predictions can be made, we explore the battery size needed for a given electricity demand timeseries (e.g. baseload, or offshore aquaculture). Our analysis finds tidal-stream energy could be much more useful than other forms of renewable energy to off-grid communities due to the predictability and persistence of the electricity supply. Moreover, our standardised power curve method will facilitate technical tidal energy resource assessment for any region.</p>

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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.

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