Performance of large arrays of point absorbing direct-driven wave energy converters

Abstract

Performance of arrays of direct-driven wave energy converters under optimal power take-off damping AIP Advances 6, 085313 (2016); 10.1063/1.4961498Performance of large arrays of point absorbing direct-driven wave energy converters Future commercial installation of wave energy plants using point absorber technology will require clusters of tens up to several hundred devices, in order to reach a viable electricity production. Interconnected devices also serve the purpose of power smoothing, which is especially important for devices using direct-driven power take off. The scope of this paper is to evaluate a method to optimize wave energy farms in terms of power production, economic viability, and resources. In particular, the paper deals with the power variation in a large array of point-absorbing direct-driven wave energy converters, and the smoothing effect due to the number of devices and their hydrodynamic interactions. A few array geometries are compared and 34 sea states measured at the Lysekil research site at the Swedish west coast are used in the simulations. Potential linear flow theory is used with full hydrodynamic interactions between the buoys. It is shown that the variance in power production depends crucially on the geometry of the array and the number of interacting devices, but not significantly on the energy period of the waves.

Methods of reducing power fluctuations in wave energy parks

“…The geometry of the array is another crucial factor for the performance of the wave energy park, as discussed in section IV C. In a previous paper, we found the variance to be reduced by three times for a semi-circular geometry with 32 WECs, as compared to a rectangular one 9 . In this study, semi-circular arrays have been included for comparison in figure 7.…”

“…The problem of reducing fluctuations in wave power parks was considered already in early works on wave energy 1,2 and has received new attention recently, when wave energy is taking the step into full-scale commercial farms. Papers of particular interest for this paper that are treating fluctuations include [3][4][5][6][7][8][9] . Many parameters might affect the performance: the number of devices, the separation between units, the characteristic dimensions of the WECs, geometry of the park, wave climate and incoming wave direction, control strategies, mooring configurations, etc.…”

Optimizing wave energy parks with over 1000 interacting point-absorbers using an approximate analytical method

“…In three earlier papers [11][12][13], properties of wave energy parks were studied as functions of various parameters. In the first two papers, the hydrodynamical interaction between devices was calculated using the boundary element potential flow solver WAMIT.…”

Control of offshore marine substation for grid-connection of a wave power farm

“…As the number of WECs in the farm increases, the relative power fluctuations are expected to reduce. This is shown experimentally for a wave power farm of three WECs in [36], and in [37] the power fluctuations are evaluated as a function of the farm layout, using 32 WECs. However, active flicker suppression may still be required, especially if the PCC is weak.…”