Tag Archives: Resource Characterization

Evaluation of the Wave Energy Conversion Efficiency in Various Coastal Environments


Eugen Rusu – Energies, June 2014

Abstract

The main objective of the present work was to assess and compare the wave power resources in various offshore and nearshore areas. From this perspective, three different groups of coastal environments were considered: the western Iberian nearshore, islands and an enclosed environment with sea waves, respectively. Some of the most representative existent wave converters were evaluated in the analysis and a second objective was to compare their performances at the considered locations, and in this way to determine which is better suited for potential commercial exploitation. Continue reading

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Wave electricity production in Italian offshore: A preliminary investigation


Silvia Bozzi, Renata Archetti, and Giuseppe Passonic – Renewable Energy, February 2014

Abstract

In this paper the feasibility of wave energy exploitation off the Italian coasts is investigated. At this aim, the energy production and the performance characteristics of three of the most promising and documented wave energy converters (AquaBuOY, Pelamis and Wave Dragon) are estimated for two of the most energetic Italian locations. The sites are Alghero, on the western coast of Sardinia and Mazara del Vallo, on the Sicily Strait and they have respectively an average annual wave power of 10.3 kW/m and 4 kW/m, and an available annual wave energy of 90 MWh/m and 35 MWh/m. Continue reading

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Tidal current power for Indonesia? An initial resource estimation for the Alas Strait


L.S. Blunden, A.S. Bahaj, N.S. Aziz – Renewable Energy, January 2013

Abstract

Indonesia – with its many narrow straits and significant tidal range – might be expected to have considerable potential for tidal current power generation. A particularly promising site is the Alas Strait, with shallow depth, high tidal current velocity and location far from major shipping lanes. In this study, a hydrodynamic numerical model of the Alas Strait was run and validated against some tidal current velocity measurements. The results of the model were then used to estimate the practically exploitable energy resources in the strait, using a development of a method used in previous resource estimations. In this method, the incident velocity on each row of an array was extracted from the model and then attenuated based on the direction of the flow and the number of rows deep into the array. In this way, the effects of practical array shape can be simulated without the need to include computationally expensive parameterization of turbines in the model. Two scenarios were considered, with and without a maximum depth limitation of 40 m. The first scenario gave an estimate of the practically exploitable annual energy yield from the Alas Strait of 330 GW h with the second scenario nearly double at 640 GW h.

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The assessment of ocean wave energy along the coasts of Taiwan


YH Lin, MC Fang – China Ocean Engineering, 2012

Abstract

The wave energy resource around the coasts of Taiwan is investigated with wave buoy data covering a 3-year period (2007–2009). Eleven study sites within the region bounded by the 21.5°N–25.5°N latitudes and 118°E–122°E longitudes are selected for analysis. The monthly moving-average filter is used to obtain the low-frequency trend based on the available hourly data. After quantifying the wave power and annual wave energy, the substantial resource is the result of Penghu buoy station, which is at the northeastern side of Penghu Island in the Taiwan Strait. It is investigated that the Penghu sea area is determined to be the optimal place for wave energy production according to its abundant resource of northeasterly monsoon waves, sheltering of the Taiwan Island, operation and maintenance in terms of seasonal conditions, and constructability of wave power devices.

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Nearshore Wave Predictions along the Oregon and Southwest Washington Coast


G. García-Medina – Masters thesis, Oregon State University, September, 2012

Abstract

This thesis contains a manuscript describing the implementation of a high resolution wave forecasting model for the coasts of Washington and Oregon. The purpose of this project was to advance the wave predictive capabilities of the states of Oregon and the southwest part of Washington by including the effects of local bathymetric features in the operational forecasts. A 30 arc-second resolution wave forecasting model was implemented making use of the WAVEWATCH III numerical code covering the coastal region from Klamath, CA to Taholah, WA. The wave forecasts extend to the continental shelf at this resolution. Continue reading

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The dynamics of an energetic tidal channel, the Pentland Firth, Scotland


MC Easton, DK Woolf, PA Bowyer – Continental Shelf Research, August 2012

Abstract

Shelf tidal stream velocities are accelerated by nearshore geographic features, such as headlands and islands. In the search for sustainable forms of electrical energy generation, such locations may become attractive for tidal stream power developments. For some prospective tidal stream energy sites, however, little is known about the intricacies of the local tidal dynamics: knowledge which is crucial to the understanding of the resource and the potential environmental consequences of its extraction.

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Numerical Wave Modeling and Wave Energy Estimation


G Galanis, G Zodiatis, D Hayes, A Nikolaidis, G Georgiou, S Stylianou, G Kallos, C Kalogeri, PC Chu and A Charalambous – Advances in Meteorology, 2013

Abstract
In a rapidly evolving operational and research framework concerning the global energy resources, new frontiers have been set for the scientific community working on environmental and renewable energy issues. In particular, new numerical techniques supporting the accurate estimation of renewable energy sources are highly emphasized. In this framework, wave energy – the energy that can be captured from sea waves – provides an alternative option with critical advantages. In the present paper, recent advances and some preliminary results obtained in two European projects will be discussed: Marina Platform and E-wave projects are focusing on the estimation of the wave energy potential in North Atlantic coastline of Europe and in Eastern Mediterranean Sea, respectively. Special emphasis is given to the utilization of numerical atmospheric and wave modeling systems able to accurately monitor the atmospheric and sea conditions in the area of interest. On the other hand, advanced statistical techniques are utilized for the local adaptation of the results and the estimation of the spatial and temporal distribution of the wave energy potential.

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Morphological Response Of High-Energy Macrotidal Beaches


TG Poate – Doctoral Dissertation, University of Plymouth, 2012

Abstract
Spatial data collected over 3 years is presented to assess the extent of morphological variability under seasonal and storm waves at four high-energy macrotidal beaches. A novel approach is adopted to identify and classify the beach response which is used to assess the relative stability of the system to changes in the dominant forcing conditions. Field measurements and modelling simulations using XBeach provide further support for a storm dominated system exhibiting relative stability. Morphologically the beaches range from dissipative to intermediate and are characterised by low tide bar/rip morphology which plays a key role in the nearshore dynamics and beach safety. Located in the north coast of Cornwall the sites are exposed to high-energy waves that dominate the stability and behaviour of beaches in this region. The growing need for marine renewable energy in the UK has led to the deployment of a Wave Hub on the seabed off the north coast of Cornwall, designed to provide grid connection for wave energy devices (WECs). As a unique development much has been done to address concerns over potential impacts cause by arrays of WECs during its construction and operational lifetime; these predicted impacts include changes in the quality of waves for surfing and effects on the beach dynamics which determines beach safety through the presence of bar/rip features. Continue reading

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The extractable power from a split tidal channel: An equivalent circuit analysis


PF Cummins –Renewable Energy, August 2012

Abstract

Considerable interest exists in the possibility of exploiting strong tidal currents as a source of renewable energy. Methods to understand and evaluate this resource have been developed for simple flow configurations, such as a tidal channel linking the open ocean to an inner basin. More complicated flow geometries involving branching channels have been considered recently. A simple prototype for this class of problem consists a tidal channel that is split by an island into two sub-channels. In-stream energy conversion devices are deployed in one of the sub-channels, while the second is left free for navigation or other purposes. The free sub-channel allows flow to be diverted away from the impeded sub-channel, which may lead to a reduction in the available power.

In the present paper, an electric circuit analogue is used to develop a linear theory for the power potential of a split tidal channel. Although limited to linear friction, this approach allows for inclusion of the effects of flow acceleration and finite basin size that have not been considered previously. Based on the equivalent circuit, analytical expressions are derived for the maximum extractable power and for the modification of the flow in each section of the channel at maximum power. Extension of the theory to multiple branching channels is discussed. Results for a few simple cases are considered.

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The TSE index – A new tool for selecting tidal stream sites in depth-limited regions


G Iglesias, M Sánchez, R Carballo, H Fernández – Renewable Energy, December 2012

Abstract
In many regions strong tidal flow occurs only in areas with restricted water depths, typically within estuaries or rias. Although in some of these areas the depth constraint may preclude the exploitation of this resource, in others it is exploitable – and substantial. The objective of this work is twofold: (i) to develop a tool, the Tidal Stream Exploitability (TSE) index, to facilitate the selection of tidal power sites in depth-limited zones, and (ii) to demonstrate it with a case study. The TSE index combines the flow and water depth information so that the areas with potential as prospective tidal power sites present large TSE values. On the contrary, areas of lesser interest – of weak flow, too shallow, or both – have small TSE values. In the case study (Ria de Ortigueira, a large estuary in NW Spain) a numerical model of the hydrodynamics is implemented. Once validated based on field data, the model is used to compute the flow velocity and power density in the estuary at different moments of the tide. Two areas present high values of power density. One is unsuitable for a tidal stream power plant due to its shallowness; the other, which does have sufficient water depth, clearly stands out in the TSE map. Thus, the TSE index is shown to facilitate the selection of tidal stream sites in depth-limited regions.

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