On the Array of Wave Energy Converters: The Case of the Coaxial-Duct OWC

2018 ◽  
Author(s):  
J. C. C. Portillo ◽  
J. C. C. Henriques ◽  
R. P. F. Gomes ◽  
L. M. C. Gato ◽  
A. F. O. Falcão
Keyword(s):  
Wave Energy ◽  
Oscillating Water Column ◽  
Economic Activities ◽  
Energy Converter ◽  
Diverse Range ◽  
Wave Energy Converters ◽  
Large Size ◽  
New Findings ◽  
Water Columns ◽  
Oscillating Water Columns

This work focuses on the initial performance assessment of an array of coaxial-duct (CD) oscillating-water-columns (owc’s) with potential to be used as multipurpose platform for the creation of value in a diverse range of offshore economic activities. The coaxial-duct owc (CD-owc) is an axisymmetric oscillating-water-column wave energy converter that has been studied for both small-size and large-size applications. This work focuses on buoys of 12 meter diameter distributed in an array of five devices, rigidly attached to each other, to form a cluster of owc’s. The objective of the study is to assess the performance of the array with this configuration and estimate the effect of parameters such as distance between devices, various modes of movements, and other constraints on the overall power output of the array. Results of different cases are compared to the performance of an isolated device to determine the interference effect of other devices. Some results validate previous research conclusions and new findings on the behavior coaxial-duct owc are presented.

scholarly journals Power Smoothing and Energy Storage Sizing of Vented Oscillating Water Column Wave Energy Converter Arrays

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1278 ◽  
Author(s):  
Gimara Rajapakse ◽  
Shantha Jayasinghe ◽  
Alan Fleming
Keyword(s):  
Energy Storage ◽  
Water Column ◽  
Wave Energy ◽  
Storage Systems ◽  
Wave Energy Converter ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Water Columns ◽  
Oscillating Water Columns

Oscillating water column wave energy converter arrays can be arranged to enhance the energy production and quality of power delivered to the grid. This study investigates four different array configurations of vented oscillating water columns and their effect on power quality and capacity of the energy storage systems required to absorb power fluctuation. Configuring the array of vented oscillating water columns as a nearshore detached breakwater allows combining the benefits of their complementary features. This increases the economic optimization of wave energy converters, paving the path to the energy market. The operations of the integration schemes are evaluated using the results obtained from simulations carried out using MATLAB/Simulink software. Simulation results show that the array of vented oscillating water columns and array of vented oscillating water columns as nearshore detached breakwater configurations increase the quality of power delivered to the grid and reduce the capacity of the energy storage systems required.

Response of the U-OWC Prototype Installed in the Civitavecchia Harbour

2018 ◽  
Author(s):  
Felice Arena ◽  
Alessandra Romolo ◽  
Giovanni Malara ◽  
Vincenzo Fiamma ◽  
Valentina Laface
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Width Ratio ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Resonant Wave ◽  
Air Pocket ◽  
Water Columns ◽  
Oscillating Water Columns

The Resonant Wave Energy Converter 3 (REWEC3) is a wave energy converter belonging to the family of Oscillating Water Columns (OWCs). It comprises an oscillating water column and an air pocket connected to a turbine, as in the traditional OWCs. In addition, it has a small vertical U-shaped duct connecting the water column to the open wave field. Because of this particular geometrical configuration, it is also known as U-Oscillating Water Column (U-OWC). The first full-scale prototype was constructed in the Port of Civitavecchia (Rome, Italy), in the context of a major port enlargement. This paper shows some results of the monitoring activity pursued on one U-OWC chamber equipped with sensors measuring water and air pressures. The activity has been conducted for about 1 year. The energetic performance of the plant is investigated in the paper, via the estimation of the capture width ratio.

Numerical Assessment on Primary Wave Energy Conversion of Oscillating Water Columns

2014 ◽  
Author(s):  
Wanan Sheng ◽  
Ray Alcorn ◽  
Tony Lewis
Keyword(s):  
Dynamic System ◽  
Energy Conversion ◽  
Wave Energy ◽  
Primary Wave ◽  
Wave Energy Conversion ◽  
Wave Energy Converters ◽  
Numerical Assessment ◽  
Water Columns ◽  
Oscillating Water Columns ◽  
Energy Converters

Oscillating water column (OWC) wave energy converters (WECs) are probably the simplest and most promising wave energy converters due to their good feasibility, reliability and survivability in practical wave energy conversions and also regarded as the most studied and developed when compared to other types of the wave energy converters. This research aims to develop a reliable numerical tool to assess the performance of the OWC wave energy converters, particularly in the primary wave energy conversion. In the numerical assessment tool, the hydrodynamics of the device and thermodynamics of the air chamber can be studied separately. However, for the complete dynamic system when a power takeoff (PTO) system is applied, these two dynamic systems are fully coupled in time-domain, in which the PTO can have a simple mathematical expression as the relation between the pressure difference across the PTO (the chamber pressure) and its flowrate through the PTO. And the application of a simple PTO pressure-flowrate relation very much simplifies the complicated aerodynamics and thermodynamics in the air turbine system so the whole dynamic system can be simplified. The methodology has been applied to a generic OWC device and the simulation results have been compared to the experimental data. It is shown that the developed numerical method is reliable in and capable of assessing the primary wave energy conversion of oscillating water columns.

scholarly journals Wave energy converter physical model design and testing: The case of floating oscillating-water-columns

2020 ◽  
Vol 278 ◽  
pp. 115638 ◽  
Author(s):  
J.C.C. Portillo ◽  
K.M. Collins ◽  
R.P.F. Gomes ◽  
J.C.C. Henriques ◽  
L.M.C. Gato ◽  
...  
Keyword(s):  
Physical Model ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Model Design ◽  
Energy Converter ◽  
Water Columns ◽  
Oscillating Water Columns ◽  
Design And Testing

scholarly journals Numerical Assessment of Onshore Wave Energy in France: Wave Energy, Conversion and Cost

2020 ◽  
Vol 8 (11) ◽  
pp. 947
Author(s):  
Philippe Sergent ◽  
Virginie Baudry ◽  
Arnaud De Bonviller ◽  
Bertrand Michard ◽  
Jérémy Dugor
Keyword(s):  
Wave Energy ◽  
Atlantic Coast ◽  
Production Costs ◽  
Wave Energy Conversion ◽  
Wave Energy Converters ◽  
Cost Of Energy ◽  
Numerical Assessment ◽  
Depth Analysis ◽  
Water Columns ◽  
Oscillating Water Columns

There are few general analyses of the interest of onshore wave energy converters (onshore WEC) in terms of resources, efficiency and cost. The case of The Channel on the Atlantic coast of France is chosen here to illustrate the issues related to onshore WEC development. The paper presents a list of potential sites with their characteristics and a more in-depth analysis of a few sites. For four onshore WEC families, the production is given with a method of calculating the efficiency and economic analysis is carried out to estimate the energy cost at two selected sites. Annual wave power levels are maximum in Bayonne with 24 kW/m, and the lengths of useful dikes vary from 60 m in Molène up to 4000 m in Cherbourg. Wave reflection on the dike is an advantage in terms of energy production. The oscillating flaps constitute the systems with the highest efficiency, and the float systems have the lowest levelized cost of energy (LCoE), followed closely by the oscillating flaps. Oscillating water columns and overtopping systems have nearly five times these LCoEs. With mass production, costs of oscillating floats and flaps will approach those of other renewable energies such as solar and wind power.

scholarly journals Performance Assessment of a Hybrid Wave Energy Converter Integrated into a Harbor Breakwater

Energies ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 236 ◽  
Author(s):  
Tomás Cabral ◽  
Daniel Clemente ◽  
Paulo Rosa-Santos ◽  
Francisco Taveira-Pinto ◽  
Tiago Morais ◽  
...  
Keyword(s):  
Wave Energy ◽  
Experimental Tests ◽  
Wave Power ◽  
Oscillating Water Column ◽  
Hybrid Wave ◽  
Energy Converter ◽  
Ansys Fluent ◽  
Wave Energy Converters ◽  
Model Study ◽  
Geometrical Scale

Seaports are highly energy demanding infrastructures and are exposed to wave energy, which is an abundant resource and largely unexploited. As a result, there has been a rising interest in integrating wave energy converters (WEC) into the breakwaters of seaports. The present work analyzes the performance of an innovative hybrid WEC module combining an oscillating water column (OWC) and an overtopping device (OWEC) integrated into a rubble mound breakwater, based on results of a physical model study carried out at a geometrical scale of 1:50. Before the experimental tests, the device’s performance was numerically optimized using ANSYS Fluent and WOPSim v3.11. The wave power captured by the hybrid WEC was calculated and the performance of the two harvesting principles discussed. It was demonstrated that hybridization could lead to systems with higher efficiencies than its individual components, for a broader range of wave conditions. The chosen concepts were found to complement each other: the OWEC was more efficient for the lower wave periods tested and the OWC for the higher. Consequently, the power production of the hybrid WEC was found to be less dependent on the wave’s characteristics.

The First Full Operative U-OWC Plants in the Port of Civitavecchia

2017 ◽  
Author(s):  
Felice Arena ◽  
Alessandra Romolo ◽  
Giovanni Malara ◽  
Vincenzo Fiamma ◽  
Valentina Laface
Keyword(s):  
Water Column ◽  
Wave Energy ◽  
Field Experiments ◽  
Full Scale ◽  
Wave Energy Converter ◽  
Small Scale ◽  
Oscillating Water Column ◽  
Energy Converter ◽  
Resonant Wave ◽  
Oscillating Water Columns

The Resonant Wave Energy Converter 3 (REWEC3) is a wave energy converter belonging to the family of Oscillating Water Columns (OWCs). It comprises an oscillating water column and an air pocket connected to a turbine, as for traditional OWCs. In addition, it has a small vertical U-shaped duct used for connecting the water column to the open wave field. Because of this particular geometrical configuration, it is also known as U-Oscillating Water Column (U-OWC). During the past decade, small scale field experiments and theoretical analyses proved its potential for full scale applications. Currently, a full-scale prototype has been operating in the Port of Civitavecchia (Rome, Italy), where a REWEC3 was constructed within the context of a major port enlargement. This paper shows some results of the monitoring activity on a single chamber equipped with pressure gauges. The results show some initial energetic performances of the REWEC3 in wind-generated seas.

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