scholarly journals Weptos Wave Energy Converters to Cover the Energy Needs of a Small Island

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 423 ◽  
Author(s):  
Lucia Margheritini ◽  
Jens Kofoed

This paper presents the details of a study performed to investigate the feasibility of a wave energy system made up of a number of Weptos wave energy converters (WECs) and sets of batteries, to provide the full energy demands of a small island in Denmark. Two different configurations with 2 and 4 Weptos machines respectively with a combined installed power of 750 kW (and a capacity factor of 0.2) are presented. One full year simulation, based a detailed hourly analysis of the power consumption and wave energy resource assessment in the surrounding sea, is used to demonstrate that both configurations, supplemented by a 3 MWh battery bank and a backup generator, can provide the energy needs of the island. The proposed configurations are selected on the basis of a forecast optimization of price estimates for the individual elements of the solutions. The simulations show that Weptos WECs actually deliver 50% more than average consumption over the year, but due to the imbalance between consumption and production, this is not enough to cover all situations, which necessitates a backup generator that must cover 5–7% of consumption, in situations where there are too few waves and the battery bank is empty.

2021 ◽  
Vol 13 (11) ◽  
pp. 2070
Author(s):  
Ana Basañez ◽  
Vicente Pérez-Muñuzuri

Wave energy resource assessment is crucial for the development of the marine renewable industry. High-frequency radars (HF radars) have been demonstrated to be a useful wave measuring tool. Therefore, in this work, we evaluated the accuracy of two CODAR Seasonde HF radars for describing the wave energy resource of two offshore areas in the west Galician coast, Spain (Vilán and Silleiro capes). The resulting wave characterization was used to estimate the electricity production of two wave energy converters. Results were validated against wave data from two buoys and two numerical models (SIMAR, (Marine Simulation) and WaveWatch III). The statistical validation revealed that the radar of Silleiro cape significantly overestimates the wave power, mainly due to a large overestimation of the wave energy period. The effect of the radars’ data loss during low wave energy periods on the mean wave energy is partially compensated with the overestimation of wave height and energy period. The theoretical electrical energy production of the wave energy converters was also affected by these differences. Energy period estimation was found to be highly conditioned to the unimodal interpretation of the wave spectrum, and it is expected that new releases of the radar software will be able to characterize different sea states independently.


Author(s):  
Jean-Baptiste Saulnier ◽  
Izan Le Crom

Located off the Guérande peninsula, SEM-REV is the French maritime facility dedicated to the testing of wave energy converters and related components. Lead by Ecole Centrale de Nantes through the LHEEA laboratory, its aim is to promote research alongside the development of new offshore technologies. To this end, the 1km2, grid-connected zone is equipped with a comprehensive instruments network sensing met-ocean processes and especially waves, with two identical directional Waverider buoys deployed on the site since 2009. For the design of moored floating structures and, a fortiori, floating marine energy converters, the knowledge of the main wave resource — for regular operation — but also extreme conditions — for moorings and device survivability — has to be as precise as possible. Also, the consideration of the multiple wave systems (swell, wind sea) making up the sea state is a key asset for the support of developers before and during the testing phase. To this end, a spectral partitioning algorithm has been implemented which enables the individual characterisation of wave systems, in particular that of their spectral peakedness which is especially addressed in this work. Peakedness has been shown to be strongly related to the groupiness of large waves and is defined here as the standard JONSWAP’s peak enhancement factor γ. Statistics related to this quantity are derived from the measurement network, with a particular focus on the extreme conditions reported on SEM-REV (Joachim storm).


2018 ◽  
Vol 30 ◽  
pp. 68-76 ◽  
Author(s):  
M. Majidi Nezhad ◽  
D. Groppi ◽  
F. Rosa ◽  
G. Piras ◽  
F. Cumo ◽  
...  

Author(s):  
Garlapati Nagababu ◽  
Ravi Patel ◽  
Seemanth Moideenkunju ◽  
Abhinaya Srinivas Bhasuru ◽  
Surendra Singh Kachhwaha ◽  
...  

Identification of the best location for wave farm installation, wave resource assessment needs to be carried out. In the present work, wave resource assessment along the Indian EEZ was carried out using the 17-year (2000 to 2016) output simulation of the third generation wave model WAVEWATCH-III (WWIII). Spatial distribution of significant wave height, mean wave energy period and annual mean of wave power is plotted. Further, the monthly and seasonal variation has been carried out to assess the effect on temporal variability at a specific location. The results show the annual mean wave power is in the range of 1–12 kW/m across the Indian EEZ. Further, it was observed that wave power along the western coast of India is more energetic than the eastern coast of India, with annual average wave power of 8–12 kW/m and 2–6 kW/m respectively. However, coastlines of Gujarat and Maharashtra experience the maximum seasonal and monthly variability across Indian EEZ, which is 2 and 3.5 respectively. By using different wave energy converters (WEC), the capacity factor and technical wave energy potential over the study area are estimated. Oceantec WEC shows maximum capacity factor (0.35) among the all selected wave energy converters. The results reveal that the electric wave power generation is 3 times more in the western coastal region as compared to the eastern coast of India.


2014 ◽  
Vol 6 ◽  
pp. 846097 ◽  
Author(s):  
Mohammed Faizal ◽  
M. Rafiuddin Ahmed ◽  
Young-Ho Lee

An overview of the most important development stages of floating point absorber wave energy converters is presented. At a given location, the wave energy resource has to be first assessed for varying seasons. The mechanisms used to convert wave energy to usable energy vary for different wave energy conversion systems. The power output of the generator will have variations due to varying incident waves. The wave structure-interaction leads to modifications in the incident waves; thus, the power output is also affected. The device has to be stable enough to prevent itself from capsizing. The point absorber will give optimum performance when the incident wave frequencies correspond to the natural frequency of the device. The methods for calculating natural frequencies for pitching and heaving systems are presented. Mooring systems maintain the point absorber at the desired location. Various mooring configurations as well as the most commonly used materials for mooring lines are discussed. An overview of scaled modelling is also presented.


2018 ◽  
Vol 224 ◽  
pp. 205-219 ◽  
Author(s):  
Markel Penalba ◽  
Alain Ulazia ◽  
Gabriel Ibarra-Berastegui ◽  
John Ringwood ◽  
Jon Sáenz

Author(s):  
Dripta Sarkar ◽  
Emile Contal ◽  
Nicolas Vayatis ◽  
Frederic Dias

The hydrodynamic analysis and estimation of the performance of wave energy converters (WECs) is generally performed using semi-analytical/numerical models. Commercial boundary element codes are widely used in analyzing the interactions in arrays comprising of wave energy conversion devices. However, the analysis of an array of such converters becomes computationally expensive, and the computational time increases as the number of devices in the system is increased. As such determination of optimal layouts of WECs in arrays becomes extremely difficult. In this study, an innovative active experimental approach is presented to predict the behaviour of theWECs in arrays. The input variables are the coordinates of the center of the wave energy converters. Simulations for training examples and validation are performed for an array of OscillatingWave Surge Converters, using the mathematical model of Sarkar et. al. (Proc. R. Soc. A, 2014). As a part of the initial findings, results will be presented on the performance of wave energy converters located well inside an array. The broader scope/aim of this research would be to predict the behaviour of the individual devices and overall performance of the array for arbitrary layouts of the system and then identify optimal layouts subject to various constraints.


2019 ◽  
Vol 9 (23) ◽  
pp. 5225
Author(s):  
Lacasa ◽  
Esteban ◽  
López-Gutiérrez ◽  
Negro ◽  
Zang

In a context of growing global awareness of environmental sustainability, given the risks associated with global warming and climate change, the transition from environmental models to highly intensive fossil fuel production towards new clean energy systems marks the future of global public agendas. In this scenario, a feasibility study of the installation of wave energy converters, such as the Sea Slot-Cone Generator (SSG) and the Oscillating Water Column (OWC), was carried out in existing breakwaters in the North of Spain, choosing Punta Langosteira (Outer Port of A Coruña), Dique Torres and Dique Norte (Port el Musel, Gijón) and Punta Lucero (Port of Bilbao). It was aimed at capturing the great energy potential of the Atlantic Ocean, as an innovative solution linked to the development of renewable energy sources of marine origin. The selection of the most optimal and efficient alternative will depend on different aspects: the quantitative availability of the wave energy resource at the study points, the production of energy obtained by the device and the capacity factor, the capacity of the wave energy facility to supply the energy consumption in every port to boost the image of “Green Port”, the constructive viability so that the condition of having the construction works only during one year and an economic estimation of each alternative.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2948
Author(s):  
Sousounis ◽  
Shek

The research presented in this paper investigates novel ways of optimizing all-electric wave energy converters for maximum wave-to-wire efficiency. In addition, a novel velocity-based controller is presented which was designed specifically for wave-to-wire efficiency maximization. In an ideal wave energy converter system, maximum efficiency in power conversion is achieved by maximizing the hydrodynamic efficiency of the floating body. However, in a real system, that involves losses at different stages from wave to grid, and the global wave-to-wire optimum differs from the hydrodynamic one. For that purpose, a full wave-to-wire wave energy converter that uses a direct-drive permanent magnet linear generator was modelled in detail. The modelling aspect included complex hydrodynamic simulations using Edinburgh Wave Systems Simulation Toolbox and the electrical modelling of the generator, controllers, power converters and the power transmission side with grid connection in MATLAB/Simulink. Three reference controllers were developed based on the previous literature: a real damping, a reactive spring damping and a velocity-based controller. All three literature-based controllers were optimized for maximum wave-to-wire efficiency for a specific wave energy resource profile. The results showed the advantage of using reactive power to bring the velocity of the point absorber and the wave excitation force in phase, which was done directly using the velocity-based controller, achieving higher efficiencies. Furthermore, it was demonstrated that maximizing hydrodynamic energy capture may not lead to maximum wave-to-wire efficiency. Finally, the controllers were also tested in random sea states, and their performance was evaluated.


Author(s):  
Changwei Liang ◽  
Junxiao Ai ◽  
Lei Zuo

The total useful wave resource around the world is estimated to be larger than 2 TW. Harvesting a small portion of the available wave energy resource could contribute significantly to meet the urgent energy demand. Therefore, a lot of wave energy converters have been developed in the past decades. Traditionally, air turbine, hydroelectric motor and linear electromagnetic motor are used in wave energy converters as the power takeoff system. Although these power takeoffs have their own advantages, power takeoffs are still recognized as the most important challenge in ocean wave energy technology. In this paper, a mechanical motion rectifier (MMR) based power takeoff system is proposed and prototyped for wave energy converter. This power takeoff system can convert the bi-directional wave motion into unidirectional rotation of the generator by integrating two one-way clutches into a rack pinion system. A 500W prototype which contains a heaving buoy and MMR-based power takeoff system was designed and fabricated. The models of power takeoff system and the corresponding single-buoy wave energy converter are built and analyzed. Lab testing of power takeoff mechanism and ocean testing of the overall ocean wave converter system are also conducted.


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