Impact of wave interactions effects on energy absorption in large arrays of wave energy converters

Abstract This paper presents a parametric study on arrays of wave energy converters (WECs). Its goal is to assess the influence of interactions between bodies on the overall yearly energy production of the array. Generic WECs (heaving cylinder and surging barge) are considered. Nine to twenty-five WECs are installed along regular square and triangular grids; the influence of the separating distance between the WECs is investigated. Results show that constructive and destructive interactions compensate each other over the considered range of wave periods. The influence of the separating distance can be limited, especially if the damping of the power take-off is tuned properly, and if the WECs have a large bandwidth. It is found that grouping the devices into arrays have generally a constructive effect. Diffracted and radiated waves in the array lead to a sufficient increase in the energy absorption which overcomes the reduction due to masking effects.

[1]  D. Evans,et al.  Arrays of three-dimensional wave-energy absorbers , 1981 .

[2]  J. Falnes,et al.  Wave-power absorption by parallel rows of interacting oscillating bodies , 1982 .

[3]  Y. Saad,et al.  GMRES: a generalized minimal residual algorithm for solving nonsymmetric linear systems , 1986 .

[4]  Matthew Folley,et al.  The effect of sub-optimal control and the spectral wave climate on the performance of wave energy converter arrays , 2009 .

[5]  Alain H. Clément,et al.  Hydrodynamic performance for small arrays of submerged spheres , 2003 .

[6]  Julien De Rouck,et al.  Performance of closely spaced point absorbers with constrained floater motion , 2009 .

[7]  A. Babarit.  Impact of long separating distances on the energy production of two interacting wave energy converters , 2010 .

[8]  L. Greengard.  The Rapid Evaluation of Potential Fields in Particle Systems , 1988 .

[9]  C. C. Mei,et al.  Comparison of wave power extraction by a compact array of small buoys and by a large buoy , 2010 .

[10]  K. Budal.  Theory for Absorption of Wave Power by a System of Interacting Bodies , 1977 .

[11]  Aurélien Babarit,et al.  An implementation of the fast multipole algorithm for wave interaction problems on sparse arrays of floating bodies , 2012 .

[12]  Vengatesan Venugopal,et al.  Modification of power characteristics in an array of floating wave energy devices , 2009 .

[13]  Johannes Falnes.  Wave-power absorption by an array of attenuators oscillating with unconstrained amplitudes , 1984 .

[14]  J. Falnes.  Ocean Waves and Oscillating Systems , 2002 .