Experimental results from the operation of aggregated wave energy converters

Journal of Applied Physics

et al. 2013

Self Cite

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.

Section: Resultssupporting

confidence: 67%

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

Journal of Applied Physics

et al. 2013

Self Cite

“…Although a lot of papers have studied arrays of a few WECs or larger arrays in regular waves, so far, there are few publications on full-scale experiments of WEC arrays, and/or large-scale arrays in irregular waves. In [9], experiments with up to three full-scale point-absorber devices were conducted off-shore at the Swedish west coast. It was shown that the standard deviation of power delivered to the electrical substation reduces with 30% and 80% with two and three WECs, respectively, as a mean for an arbitrary array member.…”

Section: Introductionmentioning

confidence: 99%

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

International Journal of Marine Energy

et al. 2015

PostprintThis is the accepted version of a paper published in International Journal of Marine Energy. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Göteman, M. (2015) Optimizing wave energy parks with over 1000 interacting point-absorbers using an approximate analytical method. Energy, Access to the published version may require subscription. N.B. When citing this work, cite the original published paper. International Journal of Marine AbstractLarge arrays of wave energy converters of point-absorber type are studied using an approximate analytical model. The model is validated against a numerical method that takes into account full hydrodynamic interactions based on linear potential flow theory. The low computational cost of the analytical model enables parameter studies of parks in the MW range and includes up to over 1000 interacting devices. The model is actuated by irregular wave data obtained at the Swedish west coast. In particular, focus is on comparing park geometries and improving park configurations to minimize the power fluctuations.

“…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.…”

Section: Introductionmentioning

confidence: 99%

Methods of reducing power fluctuations in wave energy parks

Journal of Renewable and Sustainable Energy

et al. 2014

One of the major challenges in constructing effective and economically viable wave energy parks is to reduce the large fluctuations in power output. In this paper, we study different methods of reducing the fluctuations and improve the output power quality. The parameters studied include the number of devices, the separating distance between units, the global and local geometry of the array, sea state and incoming wave direction, and the impact of including buoys of different radii in an array. Our results show that, e.g., the fluctuations as well as power per device decrease strictly with the number of interacting units, when the separating distance is kept constant. However, including more devices in a park with fixed area will not necessarily result in lowered power fluctuations. We also show that varying the distance between units affects the power fluctuations to a much larger extent than it affects the magnitude of the absorbed power. The fluctuations are slightly lower in more realistic, randomized geometries where the buoys tend to drift slightly off their mean positions, and significantly lower in semi-circular geometries as opposed to rectangular geometries.