scholarly journals Numerical Performance Study for the Buoy Shape of Point Absorber Wave Energy Converters

CFD letters ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 118-133
Author(s):  
Wan Ching Tan ◽  
Keng Wai Chan ◽  
Bee Mun Oon ◽  
How Tion Puay ◽  
Yi Leang Lim
Keyword(s):  
Wave Energy ◽  
Performance Study ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Numerical Performance ◽  
Energy Converters

Experimental and numerical comparisons of self-reacting point absorber wave energy converters in regular waves

2015 ◽  
Vol 104 ◽  
pp. 370-386 ◽  
Author(s):  
Scott J. Beatty ◽  
Matthew Hall ◽  
Bradley J. Buckham ◽  
Peter Wild ◽  
Bryce Bocking
Keyword(s):  
Wave Energy ◽  
Regular Waves ◽  
Numerical Comparisons ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Energy Converters

Performance assessments of the fully submerged sphere and cylinder point absorber wave energy converters

2019 ◽  
Vol 33 (13) ◽  
pp. 1950168 ◽  
Author(s):  
Qianlong Xu ◽  
Ye Li ◽  
Yingkai Xia ◽  
Weixing Chen ◽  
Feng Gao
Keyword(s):  
Wave Height ◽  
Wave Energy ◽  
Interaction Analysis ◽  
Wave Power ◽  
Viscous Damping ◽  
Power Performance ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Submerged Sphere ◽  
Energy Converters

Fully submerged sphere and cylinder point absorber (PA), wave energy converters (WECs) are analyzed numerically based on linearized potential flow theory. A boundary element method (BEM) (a radiation–diffraction panel program for wave-body interactions) is used for the basic wave-structure interaction analysis. In the present numerical model, the viscous damping is modeled by an equivalent linearized damping which extracts the same amount of wave energy over one cycle as the conventional quadratic damping term. The wave power capture width in each case is predicted. Comparisons are also made between the sphere and cylinder PAs which have identical geometrical scales and submerged depths. The results show that: (i) viscous damping has a greater influence on wave power performance of the cylinder PA than that of the sphere PA; (ii) the increasing wave height reduces wave power performance of PAs; (iii) the cylinder PA has a better wave power performance compared to the sphere PA in larger wave height scenarios, which indicates that fully submerged cylinder PA is a preferable prototype of WEC.

Offshore Deployment of Point Absorbing Wave Energy Converters With a Direct Driven Linear Generator Power Take-Off at the Lysekil Test Site

2014 ◽  
Author(s):  
Maria A. Chatzigiannakou ◽  
Irina Dolguntseva ◽  
Mats Leijon
Keyword(s):  
Wave Energy ◽  
New Technologies ◽  
Test Site ◽  
Underwater Robots ◽  
Safety Issues ◽  
Linear Generator ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Cost Efficient ◽  
Energy Converters

Within the year 2013, four linear generators with point absorber buoy systems were deployed in the Lysekil test site. Until now, deployments of these point absorbing wave energy converters have been expensive, time consuming, complicated and raised safety issues. In the present paper, we focus on the analysis and optimization of the offshore deployment process of wave energy converters with a linear generator power take-off which has been constructed by Uppsala University. To address the crucial issues regarding the deployment difficulties, case study of previous offshore deployments at the Lysekil test site are presented regarding such parameters as safety, cost and time efficiency. It was discovered that the deployment process can be improved significantly, mainly by using new technologies, e.g., new specialized deployment vessels, underwater robots for inspections and for connecting cables and an automatized pressurizing process. Addressing the main deployment difficulties and constrains leads us to discovery of methods that makes offshore deployments more cost-efficient and faster, in a safety context.

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.

The Economics of Multi-Axis Point Absorber Wave Energy Converters

2013 ◽  
Author(s):  
Daniel S. Richardson ◽  
George A. Aggidis
Keyword(s):  
Wave Energy ◽  
Performance Comparison ◽  
Linear Potential ◽  
Advantages And Disadvantages ◽  
Point Absorber ◽  
Wave Energy Converters ◽  
Point Absorbers ◽  
Linear Potential Theory ◽  
Economic Comparison ◽  
Energy Converters

This paper examines the economic advantages and disadvantages of multi-axis point absorber wave energy converters in comparison to conventional heave-only point absorbers. A multi-axis point absorber wave energy converter (MA-PAWEC) is classified as a point absorber device that has a power take off (PTO) system extracting energy from more than one mode of motion (e.g. heave and surge). The majority of existing point absorber devices operate in heave mode alone. Therefore the forces exerted along other axes must be resisted by the mooring system, any reciprocal component of which constitutes a wasted opportunity to extract energy. The economics of PAWECs are governed by the available resource, energy generated by the device, capital cost and operational cost. These factors are examined for MA-PAWECs and compared to a generic heave-PAWEC. For a performance comparison, a simple generic body PAWEC is examined under heave mode operation and multi-axis operation in a representative spectrum. The modelling is based on linear potential theory. The potential advantages of MA-PAWECS are identified as greater energy absorption, fewer installed devices for a given capacity, and greater array control. Disadvantages include higher capex, higher maintenance costs and sensitivity to PTO costs. The performance and costs are assigned an estimated economic scaling factor and are applied to a generic heave-PAWEC for an economic comparison of the two devices. This indicates that a multi-axis approach to point absorbers could offer a 21% lower cost of electricity than the incumbent heave-response devices.

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