A Point-Absorber-Based Wave Energy Converter for Power Production in Lebanon : Renewable Energy

Author(s):  
Guy Salame ◽  
Elio Frem ◽  
Elias Albona ◽  
Charbel Bou-Mosleh ◽  
Pierre Rahme
Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1731
Author(s):  
Dan Montoya ◽  
Elisabetta Tedeschi ◽  
Luca Castellini ◽  
Tiago Martins

Wave energy is nowadays one of the most promising renewable energy sources; however, wave energy technology has not reached the fully-commercial stage, yet. One key aspect to achieve this goal is to identify an effective control strategy for each selected Wave Energy Converter (WEC), in order to extract the maximum energy from the waves, while respecting the physical constraints of the device. Model Predictive Control (MPC) can inherently satisfy these requirements. Generally, MPC is formulated as a quadratic programming problem with linear constraints (e.g., on position, speed and Power Take-Off (PTO) force). Since, in the most general case, this control technique requires bidirectional power flow between the PTO system and the grid, it has similar characteristics as reactive control. This means that, under some operating conditions, the energy losses may be equivalent, or even larger, than the energy yielded. As many WECs are designed to only allow unidirectional power flow, it is necessary to set nonlinear constraints. This makes the optimization problem significantly more expensive in terms of computational time. This work proposes two MPC control strategies applied to a two-body point absorber that address this issue from two different perspectives: (a) adapting the MPC formulation to passive loading strategy; and (b) adapting linear constraints in the MPC in order to only allow an unidirectional power flow. The results show that the two alternative proposals have similar performance in terms of computational time compared to the regular MPC and obtain considerably more power than the linear passive control, thus proving to be a good option for unidirectional PTO systems.


2021 ◽  
pp. 108767
Author(s):  
Ru Xi ◽  
Haicheng Zhang ◽  
DaolinXu ◽  
Huai Zhao ◽  
Ramnarayan Mondal

2013 ◽  
Vol 47 (4) ◽  
pp. 164-176 ◽  
Author(s):  
Terry Lettenmaier ◽  
Annette von Jouanne ◽  
Ean Amon ◽  
Sean Moran ◽  
Alister Gardiner

AbstractThis paper describes ocean testing of the half-scale Wave Energy Technology-New Zealand (WET-NZ) prototype wave energy converter (WEC) using the Ocean Sentinel instrumentation buoy during a 6-week deployment period in August‐October 2012. These tests were conducted by the Northwest National Marine Renewable Energy Center (NNMREC) at its Pacific Ocean test site off the coast of Newport, Oregon. The WET-NZ is the product of a research consortium between Callaghan Innovation, a New Zealand Crown Entity, and Power Projects Limited (PPL), a Wellington, New Zealand private company. The Oregon deployment was project managed by Northwest Energy Innovations (NWEI), a Portland, OR firm. NNMREC is a Department of Energy sponsored partnership between Oregon State University (OSU), the University of Washington (UW), and the National Renewable Energy Laboratory (NREL). The Ocean Sentinel instrumentation buoy is a 6-m surface buoy, developed in 2012, that provides a stand-alone electrical load, WEC generator control, and data collection for WECs being tested. The Ocean Sentinel was deployed and operated for the first time during the 2012 WET-NZ tests. During these tests, the operation of the WET-NZ was demonstrated and its performance was characterized, while also proving successful deployment and operation of the Ocean Sentinel.


2020 ◽  
Vol 197 ◽  
pp. 106828 ◽  
Author(s):  
Benjamin W. Schubert ◽  
William S.P. Robertson ◽  
Benjamin S. Cazzolato ◽  
Mergen H. Ghayesh

Author(s):  
Eirini Katsidoniotaki ◽  
Edward Ransley ◽  
Scott Brown ◽  
Johannes Palm ◽  
Jens Engström ◽  
...  

Abstract Accurate modeling and prediction of extreme loads for survivability is of crucial importance if wave energy is to become commercially viable. The fundamental differences in scale and dynamics from traditional offshore structures, as well as the fact that wave energy has not converged around one or a few technologies, implies that it is still an open question how the extreme loads should be modeled. In recent years, several methods to model wave energy converters in extreme waves have been developed, but it is not yet clear how the different methods compare. The purpose of this work is the comparison of two widely used approaches when studying the response of a point-absorber wave energy converter in extreme waves, using the open-source CFD software OpenFOAM. The equivalent design-waves are generated both as equivalent regular waves and as focused waves defined using NewWave theory. Our results show that the different extreme wave modeling methods produce different dynamics and extreme forces acting on the system. It is concluded that for the investigation of point-absorber response in extreme wave conditions, the wave train dynamics and the motion history of the buoy are of high importance for the resulting buoy response and mooring forces.


2021 ◽  
Vol 321 ◽  
pp. 03003
Author(s):  
Devesh Singh ◽  
Anoop Singh ◽  
Akshoy Ranjan Paul ◽  
Abdus Samad

The paper aims to design and simulation of a wave energy harvesting system commonly known as point absorber for Ennore port located in the coastal area of Chennai, India. The geographical condition of India, which is surrounded by the three sides with seas and ocean, has enormous opportunity for power production through wave energy harvesting system. The wave energy converter device is a two-body floating system and its both parts are connected by power take-off unit which acts as spring mass damper system. In this paper, the hydrodynamic diffraction, stability analysis, frequency, and time response analysis is carried out on ansys-aqwa. The numerical results are compared with the results obtained from the similar experiments for validation of CFD solver. Effects of the properties featuring wave characteristics including wave height and wave period of Ennore port on the energy conversion, Froude-Krylov and diffraction force, response amplitude operator (RAO) are studied. Based on the study, float diameter, draft, geometry, and varying damping coefficient for power generation are optimized. Finally, the optimally designed point absorber is simulated as per Indian ocean energy harvesting standard and mass of the system, heave dimension, diffraction forces, and pressure variations are computed.


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