scholarly journals WAVE ENERGY CONVERSION AN EMERGING MODE OF RENEWABLE AND SUSTAINABLE POWER GENERATION

2013 ◽  
pp. 78-84
Author(s):  
DIGVIJAY SINGH RAGHUVANSHI ◽  
JAYESH L. MINASE
Keyword(s):  
Power Generation ◽  
Energy Conversion ◽  
Wave Energy ◽  
Ocean Waves ◽  
Future Research ◽  
Extensive Literature ◽  
Wave Energy Conversion ◽  
Power Requirement ◽  
Wave Energy Converters ◽  
Set Up

Ocean waves, if employed efficiently for generation of electricity, could result in the most economic green process (minimal carbon emission). This paper, based on the extensive literature survey conducted as a part of a B.Tech Project provides an overview of the current scenario of power generation and consumption in India thereby emphasizing on the progressively increasing power requirement and a lagging behind share of renewable energy. A scientific clarity is drawn on the basic theory behind wave generation and the key factors for assessing and deploying wave energy converters. Further, a few successful wave energy conversion techniques are discussed briefly, which posses the potential scope of future research and development and are presently employed under pre-commercial and commercial stages around the globe. A special emphasis is laid on the point absorber section which has been the area of research for the authors‘ project thereby detailing its constructional and working aspects and also discussing briefly an experimental procedure to set up a wave generator, to calculate mechanical conversion efficiency, and its scope of applicability. The conclusion is drawn in favor of the coastal communities which still rely on costly diesel for generating electricity.

scholarly journals Control Strategies Applied to Wave Energy Converters: State of the Art

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3115 ◽  
Author(s):  
Aleix Maria-Arenas ◽  
Aitor J. Garrido ◽  
Eugen Rusu ◽  
Izaskun Garrido
Keyword(s):  
Energy Conversion ◽  
Natural Frequency ◽  
Wave Energy ◽  
State Of The Art ◽  
Control Strategies ◽  
Resonance Mode ◽  
Wave Energy Conversion ◽  
Safe Operation ◽  
Incoming Wave ◽  
Wave Energy Converters

Wave energy’s path towards commercialization requires maximizing reliability, survivability, an improvement in energy harvested from the wave and efficiency of the wave to wire conversion. In this sense, control strategies directly impact the survivability and safe operation of the device, as well as the ability to harness the energy from the wave. For example, tuning the device’s natural frequency to the incoming wave allows resonance mode operation and amplifies the velocity, which has a quadratic proportionality to the extracted energy. In this article, a review of the main control strategies applied in wave energy conversion is presented along their corresponding power take-off (PTO) systems.

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 A Survey of Power Take-off Systems of Ocean Wave Energy Converters

2019 ◽  
Author(s):  
Zhenwei Liu ◽  
Ran Zhang ◽  
Han Xiao ◽  
Xu Wang
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Clean Energy ◽  
Ocean Wave ◽  
Direct Drive ◽  
Wave Energy Conversion ◽  
Drive Power ◽  
Wave Energy Converters ◽  
Ocean Wave Energy ◽  
Energy Converters

Ocean wave energy conversion as one of the renewable clean energy sources is attracting the research interests of many people. This review introduces different types of power take-off technology of wave energy converters. The main focus is the linear direct drive power take-off devices as they have the advantages for ocean wave energy conversion. The designs and optimizations of power take-off systems of ocean wave energy converters have been studied from reviewing the recently published literature. Also, the simple hydrodynamics of wave energy converters have been reviewed for design optimization of the wave energy converters at specific wave sites. The novel mechanical designs of the power take-off systems have been compared and investigated in order to increase the energy harvesting efficiency.

scholarly journals Dimensioning Methodology of Energy Storage Systems for Power Smoothing in a Wave Energy Conversion Plant Considering Efficiency Maps and Filtering Control Techniques

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3380
Author(s):  
Jorge Torres ◽  
Marcos Blanco ◽  
Marcos Lafoz ◽  
Gustavo Navarro ◽  
Jorge Nájera ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Energy Conversion ◽  
Wave Energy ◽  
Storage Systems ◽  
Wave Energy Conversion ◽  
Energy Storage Systems ◽  
Control Techniques ◽  
Power Oscillations ◽  
Selection Of

This paper aims at presenting and describing a dimensioning methodology for energy storage systems (ESS), in particular for one based on flywheels, applied for the specific application of reducing power oscillation in a wave energy conversion (WEC) plant. The dimensioning methodology takes into account the efficiency maps of the storage technology as well as the effect of the filtering control techniques. The methodology is applied to the case study of a WEC plant in operation in Spain, using real power generation profiles delivered into the electric grid. The paper firstly describes the calculation procedure of the efficiency maps for the particular technology of flywheels, although it could be extended to other storage technologies. Then, the influence of using future data values in the dimensioning process and the control of the ESS operation is analysed in depth. A moving average filter (MAF) is defined to compensate for power oscillations, studying the difference between considering prediction and not doing so. It is concluded that a filtering control using future values based on a number of samples equivalent to a 4-min time order provides an important reduction in the energy storage requirements for a power generation plant. Finally, and based on the selection of storage modules previously defined, the efficiency maps, and the MAF used for delivering the power into the grid, an optimal operation strategy is suggested for the storage modules, based on a stepped switching technique. The selection of four flywheel energy storage system (FESS) modules achieves a reduction of 50% in power oscillations, covering 85% of the frequency excursions at the grid.

scholarly journals Electrical Power Generation from the Oceanic Wave for Sustainable Advancement in Renewable Energy Technologies

2020 ◽  
Vol 12 (6) ◽  
pp. 2178 ◽  
Author(s):  
Omar Farrok ◽  
Koushik Ahmed ◽  
Abdirazak Dahir Tahlil ◽  
Mohamud Mohamed Farah ◽  
Mahbubur Rahman Kiran ◽  
...  
Keyword(s):  
Power Generation ◽  
Renewable Energy ◽  
Electrical Power Generation ◽  
Wave Energy ◽  
Electrical Power ◽  
Extensive Literature ◽  
Energy Devices ◽  
Wave Energy Converters ◽  
Oceanic Wave ◽  
Energy Converters

Recently, electrical power generation from oceanic waves is becoming very popular, as it is prospective, predictable, and highly available compared to other conventional renewable energy resources. In this paper, various types of nearshore, onshore, and offshore wave energy devices, including their construction and working principle, are explained explicitly. They include point absorber, overtopping devices, oscillating water column, attenuators, oscillating wave surge converters, submerged pressure differential, rotating mass, and bulge wave converter devices. The encounters and obstacles of electrical power generation from the oceanic wave are discussed in detail. The electrical power generation methods of the generators involved in wave energy devices are depicted. In addition, the vital control technologies in wave energy converters and devices are described for different cases. At present, piezoelectric materials are also being implemented in the design of wave energy converters as they convert mechanical motion directly into electrical power. For this reason, various models of piezoelectric material-based wave energy devices are illustrated. The statistical reports and extensive literature survey presented in this review show that there is huge potential for oceanic wave energy. Therefore, it is a highly prospective branch of renewable energy, which would play a significant role in the near future.

Design and Performance Analysis of Anchor System for a Single-Body Wave Energy Converter

2016 ◽  
Author(s):  
Rodrigo L. Banos ◽  
Hirpa G. Lemu
Keyword(s):  
Power Generation ◽  
Energy Conversion ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Wave Energy Conversion ◽  
Energy Converter ◽  
Practical Solution ◽  
Simulation Tools ◽  
Anchor System ◽  
Single Body

The last couple of decades have observed an increasing interest in development of wave energy conversion technology for both research and commercial purposes. Though slow due to several reasons, the technology shows an evident progress. Because of the oil crisis facing the energy sector in particular, wave energy is currently seen as a good alternative to fossil fuel based power generation. This has marked its footprints on rising industrial ventures in wave energy based power generation and the search for new devices is gearing up. Among the latest invented models, point wave energy converters are attractive and low investment options. These devices are much smaller than the traditional oscillating water column devices and have good performance when combined in arrays of devices, thus placing the technology in the center of industrial and academic research. This article reports the study conducted to understand the mechanics of the energy exchange in a single-body point wave energy converter device model Cape Verde, patented by the Norwegian company Euro Wave Energy. Furthermore, the article intends to give a practical solution for the design of the anchoring problem in the device. In general, the article attempts to present two completely different objectives: an academic part focusing on understanding the wave energy conversion mechanics, and the industrial development part that attempts to find a practical solution for a particular part of the device. The first step involves establishing a model that describes the motion and potential of absorbance of a conic single-body absorber. The anchor system was designed in accordance with standards provided by Det Norske Veritas, the Norwegian regulatory framework. A quasi-static method is used to calculate the load that the absorber would suffer and a pulley and cable system is proposed to drive these loads to the anchor system. After a review of the different solutions offered for offshore facilities at the present time, the model of a suction anchor is chosen. As design verification through physical testing of prototypes of conversion devices is demanding and costly, various simulation tools are appearing in the field. The application range of some of these different simulation tools has been evaluated and reported in this article.

Numerical Modelling of Fixed Oscillating Water Column Wave Energy Conversion Devices: Toward Geometry Hydraulic Optimization

2015 ◽  
Author(s):  
Irene Simonetti ◽  
Lorenzo Cappietti ◽  
Hisham El Safti ◽  
Hocine Oumeraci
Keyword(s):  
Energy Conversion ◽  
Water Column ◽  
Wave Energy ◽  
Stokes Equations ◽  
Fluid Dynamic ◽  
Experimental Models ◽  
Multiphase Model ◽  
Oscillating Water Column ◽  
Wave Energy Conversion ◽  
Set Up

The Oscillating Water Column (OWC) is one of the simplest and most studied concepts for wave energy conversion. The commercial scale diffusion of the OWC technology is, however, strongly dependent upon the device optimization. Research at a fundamental level is therefore still required. Analytical, numerical and experimental models are necessary tools for advancing in the knowledge of the system and thus promoting its passage at the commercial level. In this work, a simplified frequency domain rigid piston model has been applied to preliminary select expected ranges of air pressures and air velocities for the instrumental set up of laboratory experiments. The set up of a Computational Fluid Dynamic (CFD) model implemented in the open source OpenFOAM®1 environment is then presented. The multiphase model solves incompressible 3D Navier-Stokes equations, using Large Eddy Simulation (LES) for turbulence modelling, and adopts a Volume of Fluid method (VOF) to track the air-water interface. A preliminary validation of the model with physical tests data is conducted. The numerical approach seems to be promising for an accurate simulation of the OWC device energy conversion process. Hence, the validated model can be a useful research tool for different problems, particularly for systematic parameter studies to extend the range of conditions tested in the laboratory.

The Wave Energy Converter Based on Helmholtz Mode, Inspired by Nature

2013 ◽  
Author(s):  
Yalda Saadat ◽  
Nelson Fernandez ◽  
Reza Ghorbani
Keyword(s):  
Energy Conversion ◽  
Wave Energy ◽  
Water Channel ◽  
Ocean Waves ◽  
Resonance Phenomenon ◽  
Wave Energy Conversion ◽  
Wave Tank ◽  
Helmholtz Resonance ◽  
Wave Amplification ◽  
Pulsating Current

The present study examines a new concept of wave energy conversion inspired by geological tidal-bowls (i.e. toilet bowls) and blowholes in nature, capitalizing on the Helmholtz resonance phenomenon. Tidal-bowls are of interest because they concentrate ocean wave energy in a basin while in resonance with incoming waves. Tidal-bowls are formed as sea channels grow landwards into a water basin, which can result in a high pulsating current of water inside the channel in and out of the basin. The resonance of water inside the basin produced by asymmetry of its narrow water channel allows for the capture of Helmholtz mode, which is the most energetic mode of the ocean waves. Thus, the objective of this project is to experimentally investigate the geometry of tidal-bowls in a wave tank including the size of the basin and the channel in order to obtain Helmholtz resonance. The model in the wave tank is scaled using the Froude number. Preliminary experiments were carried out measuring the water surface, demonstrating a strong correlation of the model to the theoretical Helmholtz mode’s model, σH2 = gHB/A0L. Where a basin with maximum water depth, H, and horizontal area, A0, is connected to the sea by a narrow strait of width, B, and the strait length, L. The proposed geometry can be used to harvest wave energy through either pulsating current of the channel using a water-turbine or using an air-turbine on the top of the basin. This study aims to catalyze future works in effective applications of this model towards wave energy conversion device development. Thus, we investigated the effects of the device’s length, and the device’s winglet’s angle at the inlet of the channel on wave amplification inside the basin. In addition, we experimentally demonstrated that the flow dampening inside the channel has no effect on basin’s resonance frequency.

scholarly journals Modelling Ocean Waves and an Investigation of Ocean Wave Spectra for the Wave-to-Wire Model of Energy Harvesting

2021 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Safdar Rasool ◽  
Kashem M. Muttaqi ◽  
Danny Sutanto
Keyword(s):  
Time Series ◽  
Energy Harvesting ◽  
Energy Conversion ◽  
Wave Energy ◽  
Ocean Waves ◽  
Ocean Wave ◽  
Wave Spectra ◽  
Wave Energy Conversion ◽  
Peak Period ◽  
Ocean Wave Energy

Ocean wave energy is an abundant and clean source of energy; however, its potential is largely untapped. Although the concept of energy harvesting from ocean waves is antiquated, the advances in wave energy conversion technologies are embryonic. In many major studies related to wave-to-wire technologies, ocean waves are considered to be regular waves with a fixed amplitude and frequency. However, the actual ocean waves are the sum of multiple frequencies that exhibit a particular sea state with a significant wave height and peak period. Therefore, in this paper, detailed modelling of the ocean waves is presented and different wave spectra are analyzed. The wave spectra will eventually be used for the generation of wave elevation time series. Those time series can be used for the wave-to-wire model-based studies for improved investigations into wave energy conversion mechanisms, mimicking the real ocean conditions.

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