Skip to main content Accessibility help

Wave-power extraction by a compact array of buoys

  • XAVIER GARNAUD (a1) and CHIANG C. MEI (a2)


The majority of existing single-unit devices for extracting power from sea waves relies on resonance at the peak frequency of the incident wave spectrum. Such designs usually call for structural dimensions not too small compared to a typical wavelength and yield high efficiency only within a limited frequency band. A recent innovation in Norway departs from this norm by gathering many small buoys in a compact array. Each buoy is too small to be resonated in typical sea conditions. In this article a theoretical study is performed to evaluate this new design. Within the framework of linearization, we consider a periodic array of small buoys with similarly small separation compared to the typical wavelength. The method of homogenization (multiple scales) is used to derive the equations governing the macroscale behaviour of the entire array. These equations are then applied to energy extraction by an infinite strip of buoys, and by a circular array. In the latter case, advantages are found when compared to a single buoy of equal volume.


Corresponding author

Email address for correspondence:


Hide All

Present address: Laboratoire d'Hydrodynamique – Ecole Polytechnique, 91128 Palaiseau, France



Hide All
Abramowitz, M. & Stegun, I. A. 1964 Handbook of Mathematical Functions. Dover Publications.
Black, J. L., Mei, C. C. & Bray, M. C. G. 1971 Radiation and scattering of water waves by rigid bodies. J. Fluid Mech. 46 (1), 151164.
Budal, K. & Falnes, J. 1980 Interacting point absorbers with controlled motion. In Power from Sea Waves. Academics Press.
Chamberlain, P. G. 2007 Water wave scattering by finite arrays of circular structures. IMA J. Appl. Math. 72 (1), 5266.
Dalrymple, R. A., Losada, M. A. & Martin, P. A. 1991 Reflection and transmission from porous structures under oblique wave attack. J. Fluid Mech. 224, 625644.
Falnes, J. 1980 Radiation impedance matrix and optimum power absorption for interacting oscillators in surface waves. Appl. Ocean Res. 2 (2), 7580.
Falnes, J. 1984 Wave-power absorption by an array of attenuators oscillating with unconstrained amplitudes. Appl. Ocean Res. 6 (1), 1622.
Falnes, J. 2002 Ocean Waves and Oscillating Systems. Cambridge University Press.
Falnes, J. & Budal, K. 1982 Wave-power absorption by parallel rows of interacting oscillating bodies. Appl. Ocean Res. 4 (4), 194207.
Li, Y. & Mei, C. C. 2007 Bragg scattering by a line array of small cylinders in a waveguide. Part 1. Linear aspects. J. Fluid Mech. 583, 161187.
Linton, C. M. & Evans, D. V. 1990 The interaction of waves with arrays of vertical cylinders. J. Fluid Mech. 215, 549569.
Linton, C. M. & Evans, D. V. 1992 The radiation and scattering of surface waves by a vertical circular cylinder in a channel. Phil. Trans.: Phys. Sci. Engng 338 (1650), 325357.
Linton, C. M. & Mclver, R. 1996 The scattering of water waves by an array of circular cylinders in a channel. J. Engng Math. 30, 661682.
Manihar, H. D. & Newman, J. N. 1997 Wave diffraction by a long array of cylinders. J. Fluid Mech. 339, 309330.
McIver, P. 1998 The dispersion relation and eigenvalue expansion for water waves in porous structures. J. Engng Math. 34, 319334.
Mei, C. C., Stiassnie, M. & Yue, D. K. P. 2005 Theory and Application of Ocean Surface Waves. World Scientific.
Mynett, A. E., Serman, D. D. & Mei, C. C. 1979 Characteristics of Salter's cam for extracting energy from ocean waves. Appl. Ocean Res. 1, 1320.
Newman, J. N. 1979 Absorption of wave energy by elongated bodies. Appl. Ocean Res. 1, 189196.
de O. Falcao, A. F. 2002 Wave-power absorption by a periodic linear array of oscillating water columns. Ocean Engng 29 (4), 11641186.
MathJax is a JavaScript display engine for mathematics. For more information see

Wave-power extraction by a compact array of buoys

  • XAVIER GARNAUD (a1) and CHIANG C. MEI (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed