Wave Energy Assessments in the Coastal Environment of Portugal Continental

2008 ◽  
Author(s):  
Eugen Rusu ◽  
C. Guedes Soares
Keyword(s):  
Wave Energy ◽  
Numerical Models ◽  
Specific Area ◽  
Wave Climate ◽  
Coastal Environment ◽  
Wave Power ◽  
Relevant Parameter ◽  
Density Spectrum ◽  
Energy Devices ◽  
Power Resources

The potential for wave energy extraction can be obtained from the analysis of the wave climate which can be determined with numerical models. The wave energy devices can be deployed in offshore, nearshore and shoreline. From this reason, it is important to be able to assess properly the spatial distribution of the wave energy in various locations from the offshore to the coastline in a specific area. The methodology proposed here considers a SWAN based wave model system focusing in the Portuguese continental coastal environment from deep water towards the nearshore. An analysis of the average and high energetic conditions was first performed for a ten-year period, between 1994 and 2003, considering the most relevant in situ measurements available in the Portuguese nearshore. In this way both the average and high energetic conditions corresponding to the Portuguese continental costal environment have been properly defined. For the most relevant average wave conditions, SWAN simulations were performed in some medium resolution areas covering the northern and central parts of Portugal continental, which are traditionally considered richer in wave power resources. The present work allows the identification of some locations in the continental coastal environment of Portugal with greater potential from the point of view of wave power resources. An important observation is related to the fact that the wave power depends on the product between the energy density spectrum and the group velocity of waves. This means that, although the significant wave height is a relevant parameter when assessing the wave power in a specific site, a location having in general higher wave heights is not necessarily also the richest in wave power.

scholarly journals Modeling Sea Ice Effects for Wave Energy Resource Assessments

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3482
Author(s):  
Ruth Branch ◽  
Gabriel García-Medina ◽  
Zhaoqing Yang ◽  
Taiping Wang ◽  
Fadia Ticona Rollano ◽  
...  
Keyword(s):  
Sea Ice ◽  
Wave Height ◽  
Wave Energy ◽  
Numerical Models ◽  
Energy Resource ◽  
Wave Climate ◽  
Wave Power ◽  
Wave Energy Converters ◽  
Wave Models ◽  
Mean Square Errors

Wave-generated power has potential as a valuable coastal resource, but the wave climate needs to be mapped for feasibility before wave energy converters are installed. Numerical models are used for wave resource assessments to quantify the amount of available power and its seasonality. Alaska is the U.S. state with the longest coastline and has extensive wave resources, but it is affected by seasonal sea ice that dampens the wave energy and the full extent of this dampening is unknown. To accurately characterize the wave resource in regions that experience seasonal sea ice, coastal wave models must account for these effects. The aim of this study is to determine how the dampening effects of sea ice change wave energy resource assessments in the nearshore. Here, we show that by combining high-resolution sea ice imagery with a sea ice/wave dampening parameterization in an unstructured grid, the Simulating Waves Nearshore (SWAN) model improves wave height predictions and demonstrates the extent to which wave power decreases when sea ice is present. The sea ice parametrization decreases the bias and root mean square errors of wave height comparisons with two wave buoys and predicts a decrease in the wave power of up to 100 kW/m in areas around Prince William Sound, Alaska. The magnitude of the improvement of the model/buoy comparison depends on the coefficients used to parameterize the wave–ice interaction.

Modelling Wave Energy Resources in the Irish West Coast

2011 ◽  
Author(s):  
A. Rute Bento ◽  
Paulo Martinho ◽  
Ricardo Campos ◽  
C. Guedes Soares
Keyword(s):  
Wave Energy ◽  
West Coast ◽  
Wave Climate ◽  
Extensive Study ◽  
Wave Power ◽  
Target Area ◽  
Wave Models ◽  
The Time Domain ◽  
Validation Tests ◽  
Buoy Data

In order to assess the potential wave energy extraction, a study is made to validate a model that can be used to characterize Ireland’s wave climate in a more extensive study. The target area is the Irish West Coast, known for having the highest average wave power in Europe. The wave conditions in the coastal area were characterized by coupling the wave models SWAN and WAVEWATCH III. Validation tests are carried out with buoy data so that the model’s performance can be evaluated. The wave parameters considered for the comparisons in the time domain are significant wave height and mean period, and the spatial distribution of wave energy is examined in a case study. Theoretical values of wave power are obtained for sites close to the coast and in particular for the two tests sites of Galway and Belmullet.

scholarly journals Hydrodynamics and Morphodynamics Performance Assessment of Three Coastal Protection Structures

2020 ◽  
Vol 8 (3) ◽  
pp. 175 ◽  
Author(s):  
Bárbara F. V. Vieira ◽  
José L. S. Pinho ◽  
Joaquim A. O. Barros ◽  
José S. Antunes do Carmo
Keyword(s):  
Wave Energy ◽  
Numerical Models ◽  
Great Part ◽  
Wave Climate ◽  
Extreme Weather Events ◽  
Coastal Protection ◽  
Negative Consequences ◽  
Coastal Zones ◽  
Wave Direction ◽  
Wave Condition

Coastal areas accommodate a great part of large metropolises as they support a great amount of economic and leisure activities. The attraction of people to coastal zones is contributing to an intense and continuous urbanization of these areas, while the ecosystems are threatened by the increase of natural extreme weather events (e.g., intensity and duration of storms, floods), which interfere with local wave climate and changes in morphological beach characteristics. Protection of coastal zones predisposed to coastline recession, due to the action of high tides, high sediment transport deficit, and high wave energy, may involve various coastal structures to reduce or at least to mitigate coastal erosion problems. Many of the current coastal protections (notably groins, seawalls, and emerged breakwaters) were built with a single purpose, which was to protect at all costs without environmental or economic concerns, especially maintenance costs, or the negative consequences that such structures could cause up to considerable distances along the coast. The current concept of integrated coastal zone management presupposes studies involving other types of concerns and more actors in the decision-making process for the implementation of coastal works. In this context, multifunctional structures emerge and are increasingly frequent, such as the so-called multifunctional artificial reefs (MFARs), with the aim of improving leisure, fishing, diving, and other sporting activities, in addition to coastal protection. MFARs are in fact one of the latest concepts for coastal protection. Behind the search for more efficient and sustainable strategies to deal with coastal retreat, this study focused on a comparison between the performance of two traditional coastal protection solutions (submerged detached breakwater and emerged detached breakwater) and an MFAR on a particular coastal stretch. In order to analyse the hydro- (wave height and wave energy dissipation) and morphodynamics (sediment accumulation and erosion areas, and bed level) of the structures and beach interactions, two numerical models were used: SWAN (Simulation WAves Nearshore) for hydrodynamics and XBeach for hydrodynamics and morphodynamics. In addition, a comparison between SWAN and XBeach hydrodynamic results was also performed. From the simulations conducted by SWAN and XBeach, it can be concluded that amongst all structures, the emerged detached breakwater was the most efficient in reducing significant wave heights at a larger scale due to the fact that it constituted a higher obstacle to the incoming waves, and that, regarding both submerged structures (detached breakwater and the MFAR), the MFAR presented a more substantial shadow zone. Regarding morphodynamics, the obtained results presented favourable tendencies to sediment accretion near the shoreline, as well as at the inward areas for the three structures, especially for the emerged detached breakwater and for the MFAR in both wave directions. However, for the west wave direction, along the shoreline, substantial erosion was observed for both structures with more noticeable values for the emerged detached breakwater. For all the northwest wave direction scenarios, no noticeable erosion areas were visible along the shoreline. Overall, considering the balance of erosion and accretion rates, it can be concluded that for both wave predominance, the submerged detached breakwater and the MFAR presented better solutions regarding morphodynamics. The MFAR storm wave condition performed in XBeach indicated substantial erosion areas located around the structure, which added substantial changes in the bed level.

A Design for the Wave Power Generation Conversion Device

2014 ◽  
Vol 1030-1032 ◽  
pp. 472-475
Author(s):  
Shi Ming Wang ◽  
Yao Li ◽  
Hao Zhan ◽  
Ka Tian
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Control Device ◽  
Wave Power ◽  
Good Prospect ◽  
Energy Devices ◽  
New Energy ◽  
Power Generation Equipment ◽  
Torque Capacity ◽  
Wave Power Generation

In recent years, the concept of renewable energy has been deepening and popularization, all kinds of new energy technology is developed by leaps and bounds, a growing number of wave energy devices has been put into use and has a very good prospect. In wave power generation equipment, the conversion transmission device is a very important unit, which involving energy transfer, adjustment, stable output and buffer storage, so it need to be well designed to satisfy the operational requirement by taking advantage of different parts. By analyzing the commonly used conversion transmission devices, the characteristics of transmission devices and wave power generation equipments, we proposing a design of a flexible transmission device which can change its torque capacity with clutch automatic control device, in the form of its layout to drive a train of thought for the design wave energy conversion.

scholarly journals A Preliminary Study of Wave Energy Resource Using an HF Marine Radar, Application to an Eastern Southern Pacific Location: Advantages and Opportunities

2021 ◽  
Vol 13 (2) ◽  
pp. 203
Author(s):  
Valeria Mundaca-Moraga ◽  
Rodrigo Abarca-del-Rio ◽  
Dante Figueroa ◽  
James Morales
Keyword(s):  
High Resolution ◽  
Wave Energy ◽  
High Frequency ◽  
Numerical Models ◽  
Energy Resource ◽  
Hf Radar ◽  
Wave Power ◽  
High Concentration ◽  
Wave Radar ◽  
Temporal And Spatial

As climate change is of global concern, the electric generation through fossil fuel is progressively shifted to renewable energies. Among the renewables, the most common solar and wind, the wave energy stands for its high-power density. Studies about wave energy resource have been increasing over the years, especially in coastal countries. Several research investigations have assessed the global wave power, with higher values at high latitudes. However, to have a precise assessment of this resource, the measurement systems need to provide a high temporal and spatial resolution, and due to the lack of in-situ measurements, the way to estimate this value is numerical. Here, we use a high-frequency radar to estimate the wave energy resource in a nearshore central Chile at a high resolution. The study focuses near Concepción city (36.5° S), using a WERA (WavE RAdar) high frequency (HF) radar. The amount of annual energy collected is calculated. Analysis of coefficient of variation (COV), seasonal variability (SV), and monthly variability (MV) shows the area's suitability for installing a wave energy converter device due to a relatively low variability and the high concentration of wave power obtained. The utility of HF radars in energy terms relies on its high resolution, both temporal and spatial. It can then compare the location of interest within small areas and use them as a complement to satellite measurements or numerical models, demonstrating its versatility.

Nonlinear Analysis of an Oscillating Wave Surge Converter in Frequency Domain via Statistical Linearization

2020 ◽  
Author(s):  
Leandro S. P. da Silva ◽  
Nataliia Y. Sergiienko ◽  
Benjamin S. Cazzolato ◽  
Boyin Ding ◽  
Celso P. Pesce ◽  
...  
Keyword(s):  
Nonlinear Analysis ◽  
Frequency Domain ◽  
Wave Energy ◽  
Numerical Models ◽  
Computational Cost ◽  
Viscous Drag ◽  
Design Parameters ◽  
Statistical Linearization ◽  
Mean Power ◽  
Energy Devices

Abstract Wave energy devices operate in resonant conditions to optimize power absorption, which leads to large displacements. As a result, nonlinearities play an important role in the system dynamics and must be accounted for in the numerical models for realistic prediction of the power generated. In general, time domain (TD) simulations are employed to capture the effects of the nonlinearities. However, the computational cost associated with these simulations is considerably higher compared to linear frequency domain (FD) methods. In this regard, the following work deals with the nonlinear analysis of an oscillating wave surge converter (OWSC) in the FD via the statistical linearization (SL) technique. Four nonlinearities for the proposed device are addressed: Coulomb-like torque regulated by the direction of motion, viscous drag torque, nonlinear buoyant net torque, and parametric excitation torque modulated by the flap angle. The reliability of the SL technique is compared with nonlinear TD simulations in terms of response probability distribution and power spectrum density (PSD) of the response and torque; and mean power produced. The results have demonstrated a good agreement between TD simulations and SL, while the computation time of the SL model is approximately 3 orders of magnitude faster. As a result, SL is a valuable tool to assess the OWSC performance under various wave scenarios over a range of design parameters, and can assist the development of such wave energy converters (WECs).

scholarly journals Ηydrodynamic Response and Produced Power of a Combined Structure Consisting of a Spar and Heaving Type Wave Energy Converters

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 225
Author(s):  
Constantine Michailides
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Hydrodynamic Interaction ◽  
Numerical Models ◽  
Interaction Effects ◽  
Irregular Waves ◽  
Wave Power ◽  
Wave Energy Converters ◽  
Combined Structure ◽  
Energy Converters

During the past years, researchers have studied both numerically and experimentally multibody wave-wind combined energy structures supporting wind turbines and different types of Wave Energy Converters (WECs); rigid body hydrodynamic assumptions have been adopted so far for the development of their numerical models and the assessment of their produced power. In the present paper a numerical model that is based on the use of generalized modes addressing wave-structure interaction effects for the case of a multibody wave-wind combined structure is developed and presented. Afterwards, the developed numerical model is used for the assessment of the hydrodynamic response and the prediction of the produced power of different possible configurations of the updated WindWEC concept which consists of a spar supporting a wind turbine and one, two, three or four heaving type WEC buoys. The combined effects of the center-to-center distance of the WEC and spar platform, the number of the WECs and the grid configuration of spar and WECs on the hydrodynamic interaction between the different floating bodies, spar and WEC buoys, and consequently on their response and wave power production are examined for regular and irregular waves. Strong hydrodynamic interaction effects exist for small distance between spar and WECs that result to the decrease of the produced power. Power matrices of the updated WindWEC concept are presented for all examined configurations with different number of WECs. Moreover, the annual produced power of the updated WindWEC in two sites is estimated and presented. The generalized modes analysis presented in this paper is generic and can be used for the early stage assessment of wave-wind combined energy structures with low computational cost. The updated WindWEC can be used in sea sites with different environmental characteristics while extracting valuable amount of wave power.

scholarly journals Wave-to-Wire Model Development and Validation for Two OWC Type Wave Energy Converters

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3977 ◽  
Author(s):  
Pierre Benreguig ◽  
James Kelly ◽  
Vikram Pakrashi ◽  
Jimmy Murphy
Keyword(s):  
Wave Energy ◽  
Numerical Models ◽  
Power Conversion ◽  
Electrical Power ◽  
Model Development ◽  
Wave Structure ◽  
Experimental Tests ◽  
Wave Climate ◽  
Type Wave ◽  
Conversion Stage

The Tupperwave device is a closed-circuit oscillating water column (OWC) wave energy converter that uses non-return valves and two large fixed-volume accumulator chambers to create a smooth unidirectional air flow, harnessed by a unidirectional turbine. In this paper, the relevance of the Tupperwave concept against the conventional OWC concept, that uses a self-rectifying turbine, is investigated. For this purpose, wave-to-wire numerical models of the Tupperwave device and a corresponding conventional OWC device are developed and validated against experimental tests. Both devices have the same floating spar buoy structure and a similar turbine technology. The models include wave-structure hydrodynamic interaction, air turbines and generators, along with their control laws in order to encompass all power conversion stages from wave to electrical power. Hardware-in-the-loop is used to physically emulate the last power conversion stage from mechanic to electrical power and hence validate the control law and the generator numerical model. The dimensioning methodology for turbines and generators for power optimisation is explained. Eventually, the validated wave-to-wire numerical models of the conventional OWC and the Tupperwave device are used to assess and compare the performances of these two OWC type wave energy device concepts in the same wave climate. The benefits of pneumatic power smoothing by the Tupperwave device are discussed and the required efficiency of the non-return valves is investigated.

Power Absorption by Arrays of Interacting Vertical Axisymmetric Wave-Energy Devices

1997 ◽  
Vol 119 (4) ◽  
pp. 244-251 ◽  
Author(s):  
S. A. Mavrakos ◽  
A. Kalofonos
Keyword(s):  
Multiple Scattering ◽  
Wave Energy ◽  
Numerical Results ◽  
Hydrodynamic Characteristics ◽  
Wave Power ◽  
Interference Effects ◽  
Power Absorption ◽  
Energy Devices ◽  
Single Body ◽  
Absorption Characteristics

The paper deals with the evaluation of the optimum wave-power absorption characteristics of arrays of interacting wave-energy devices. The hydrodynamic interference effects among the devices are exactly accounted for using a method that can solve the problem to any desired accuracy. The method is based on single-body hydrodynamic characteristics that are properly combined through the physical idea of multiple scattering to account for interaction effects. Extensive numerical results for a variety of different array arrangements and individual device geometries are presented and comparisons are made to predictions based on approximate theories, the accuracy of which is critically assessed.

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