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.

Optimization of Mooring Configuration Parameters of Floating Wave Energy Converters

2011 ◽  
Author(s):  
Pedro C. Vicente ◽  
Anto´nio F. O. Falca˜o ◽  
Paulo A. P. Justino
Keyword(s):  
Wave Energy ◽  
Oil And Gas ◽  
Wave Energy Converter ◽  
Domain Model ◽  
Floating Point ◽  
Mooring System ◽  
Energy Converter ◽  
Energy Devices ◽  
Wave Energy Converters ◽  
Energy Converters

Floating point absorbers devices are a large class of wave energy converters for deployment offshore, typically in water depths between 40 and 100m. As floating oil and gas platforms, the devices are subject to drift forces due to waves, currents and wind, and therefore have to be kept in place by a proper mooring system. Although similarities can be found between the energy converting systems and floating platforms, the mooring design requirements will have some important differences between them, one of them associated to the fact that, in the case of a wave energy converter, the mooring connections may significantly modify its energy absorption properties by interacting with its oscillations. It is therefore important to examine what might be the more suitable mooring design for wave energy devices, according to the converters specifications. When defining a mooring system for a device, several initial parameters have to be established, such as cable material and thickness, distance to the mooring point on the bottom, and which can influence the device performance in terms of motion, power output and survivability. Different parameters, for which acceptable intervals can be established, will represent different power absorptions, displacements from equilibrium position, load demands on the moorings and of course also different costs. The work presented here analyzes what might be, for wave energy converter floating point absorber, the optimal mooring configuration parameters, respecting certain pre-established acceptable intervals and using a time-domain model that takes into account the non-linearities introduced by the mooring system. Numerical results for the mooring forces demands and also motions and absorbed power, are presented for two different mooring configurations for a system consisting of a hemispherical buoy in regular waves and assuming a liner PTO.

scholarly journals Revisiting Theoretical Limits for One-Degree-of-Freedom Wave Energy Converters

2020 ◽  
pp. 1-11
Author(s):  
Nathan Tom
Keyword(s):  
Power Generation ◽  
Wave Energy ◽  
Degree Of Freedom ◽  
Upper And Lower Bounds ◽  
Complex Conjugate ◽  
Hydrodynamic Coefficients ◽  
Damping Coefficients ◽  
Wave Energy Converters ◽  
Heave Motion ◽  
Energy Converters

Abstract This work revisits the theoretical limits of one-degree-of-freedom wave energy converters (WECs). This paper considers the floating sphere used in the OES Task 10 WEC modeling and verification effort for analysis. Analytical equations are derived to determine bounds on displacement amplitude, time-averaged power (TAP), and power-take-off (PTO) force. A unique result found shows that the TAP absorbed by a WEC can be defined solely by the inertial properties and radiation hydrodynamic coefficients. In addition, a unique expression for the PTO force was derived that provides upper and lower bounds when resistive control is used to maximize power generation. For complex conjugate control, this same expression only provides a lower bound, as there is theoretically no upper bound. These bounds assist in comparing the performance of the floating sphere if it were to extract energy using surge or heave motion. The analysis shows because of differences in hydrodynamic coefficients for each oscillating mode, there are different frequency ranges that provide better power capture efficiency. The influence of a motion constraint on TAP while utilizing a nonideal power take-off is examined and found to reduce the losses associated with bidirectional energy flow. The expression to calculate TAP with a nonideal PTO is modified by the mechanical-to-electrical efficiency and the ratio of the PTO spring and damping coefficients. The PTO spring and damping coefficients were separated in the expression, allowing for limits to be set on the PTO coefficients to ensure net power generation.

scholarly journals Wave Energy Assessment at Valencia Gulf and Comparison of Energy Production of Most Suitable Wave Energy Converters

2020 ◽  
Vol 17 (22) ◽  
pp. 8473
Author(s):  
Raúl Cascajo ◽  
Emilio García ◽  
Eduardo Quiles ◽  
Francisco Morant ◽  
Antonio Correcher
Keyword(s):  
Renewable Energy ◽  
Wave Energy ◽  
Energy Demand ◽  
Alternative Energy ◽  
Average Energy ◽  
Wave Climate ◽  
Energy Output ◽  
Renewable Sources ◽  
Wave Energy Converters ◽  
Energy Converters

Seaports’ energy strategy should rely on the use of renewable energy. Presently, the share of renewable energy used by many of the ports worldwide is negligible. Some initiatives are in the process of implementation to produce some of the energy used by the Port of Valencia, one the largest ports in the Mediterranean Basin. Among these initiatives, a photovoltaic plant with an installed capacity of 5.5 MW is under a tendering process and the assessment studies for the deployment of three to five windmills are close to being finished. However, this is not enough to make it a “zero emissions port” as some of the energy demand would still be covered by fossil fuels. Therefore, we should consider clean alternative energy sources. This article analyses the wave energy resources in the surroundings of the Port of Valencia using a 7-year series of data obtained from numerical modelling (forecast). The spatial distribution of wave power is analysed using data from 3 SIMAR points at Valencia Bay and is compared to the data obtained by the Valencia Buoy I (removed in 2005). The obtained results are used to estimate the power matrices and the average energy output of two wave energy converters suitable to be integrated into the port’s infrastructure. Finally, the wave energy converters’ production is compared to the average amount of energy that is forecast to be obtained from other renewable sources such as solar and wind. Due to the nature of the Gulf’s wave climate (mostly low waves), the main conclusion is that the energy obtainable from the waves in the Valencia Gulf will be in correlation with such climate. However, when dealing with great energy consumers every source of production is worthwhile and further research is needed to optimize the production of energy from renewable sources and its use in an industrial environment such as ports.

Optimising Reactive Control in Non-Ideal Efficiency Wave Energy Converters

2014 ◽  
Author(s):  
T. Strager ◽  
A. Martin dit Neuville ◽  
P. Fernández López ◽  
G. Giorgio ◽  
T. Mureşan ◽  
...  
Keyword(s):  
Optimal Control ◽  
Wave Energy ◽  
Electrical Power ◽  
Control Parameters ◽  
Reactive Control ◽  
Simple Method ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
The Mean ◽  
Energy Converters

When analytically optimising the control strategy in wave energy converters which use a point absorber, the efficiency aspect is generally neglected. The results presented in this paper provide an analytical expression for the mean harvested electrical power in non-ideal efficiency situations. These have been derived under the assumptions of monochromatic incoming waves and linear system behaviour. This allows to establish the power factor of a system with non-ideal efficiency. The locus of the optimal reactive control parameters is then studied and an alternative method of representation is developed to model the optimal control parameters. Ultimately we present a simple method of choosing optimal control parameters for any combination of efficiency and wave frequency.

A Hybrid Power Generation Platform Combining Floating Wind Turbine and Oscillating Water Column Wave Energy Converters

2019 ◽  
Author(s):  
Zheng Chen ◽  
Weijian Zeng ◽  
Ming Tan ◽  
Dahai Zhang ◽  
Yulin Si
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Water Column ◽  
Wave Energy ◽  
Wind Farms ◽  
Offshore Wind ◽  
Oscillating Water Column ◽  
Offshore Wind Farms ◽  
Wave Energy Converters ◽  
Energy Converters

Abstract Recent years have seen rapid development in offshore wind technology. Particularly, floating offshore wind turbines possess great potential in deep water coastal places around the world, though they are now still in the demonstration phase. At the same time, the unused wave energy is also abundant at the sites of offshore wind farms, especially those in deep sea regions. Collecting wave energy in offshore wind farms might benefit both total energy production and reduce maintenance cost. Therefore, integrating offshore wind turbine with wave energy conversion devices could be a good idea to achieve higher efficiency and lower cost. In this paper, we report a combined wind and wave energy power generation concept called WindOWC, which constits of a 5MW wind turbine and three oscillating-water-column (OWC) wave energy converters (WECs). The wind turbine is mounted on a semi-submersible floating platform, which is similar to OC4-semibsubmersible, and the OWCs are located in its three offset columns. In this design, the wind turbine and WECs share the same supporting platform and the power transmission system, thus is expected to reduce the cost of energy. Also, it is possible the OWCs may improve the platform dynamic performance by providing positive damping through controlling the air turbine rotational speed. In this work, we describe the geometry properties of the proposed WindOWC concept and conduct preliminary hydrodynamic analysis using potential flow theory. The ANSYS AQWA is used to obtain the system dynamic responses in frequency and time domain, respectively. The OWC dynamics and expected positive damping from them will be investigated in the future.

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