Coastal defence through wave farms

Abstract

The possibility of using wave farms for coastal defence warrants investigation because wave energy is poised to become a major renewable in many countries over the next decades. The fundamental question in this regard is whether a wave farm can be used to reduce beach erosion under storm conditions. If the answer to this question is positive, then a wave farm can have coastal defence as a subsidiary function, in addition to its primary role of producing carbon-free energy. The objective of this work is to address this question by comparing the response of a beach in the face of a storm in two scenarios: with and without the wave farm. For this comparison a set of ad hoc impact indicators is developed: the Bed Level Impact (BLI), beach Face Eroded Area (FEA), Non-dimensional Erosion Reduction (NER), and mean Cumulative Eroded Area (CEA); and their values are determined by means of two coupled models: a high-resolution wave propagation model (SWAN) and a coastal processes model (XBeach). The study is conducted through a case study: Perranporth beach (UK). Backed by a welldeveloped dune system, Perranporth has a bar between-5 m and-10 m. The results show that the wave farm reduces the eroded volume by as much as 50 per cent and thus contributes effectively to coastal protection. This synergy between marine renewable energy and coastal defence may well contribute to improving the viability of wave farms through savings in conventional coastal protection.

Performance of submerged nearshore sand-filled geosystems for coastal protection

“…Examples of such techniques are, for instance, the artificial infill of a beach with sand, concentrated sand nourishments (De Vriend and Van Koningsveld, 2012), the construction of wave farms (Abanades et al, 2014a(Abanades et al, , 2014b, and also coastal structures incorporating sand-filled geosystems. Within this context the use of sand-filled geosystems in coastal engineering is of growing interest and is a solution in full development as far as materials, applications and design tools are concerned.…”

Offshore Wind and Wave Energy Assessment around Malè and Magoodhoo Island (Maldives)

“…A solution to significantly decrease the production costs of blue energies would be to develop hybrid technologies, i.e., co-locating floating/fixed WTGs and WECs at offshore locations, possibly by promoting multi-use platforms [13][14][15][16][17][18][19][20][21][22][23]. The combination of wind and wave energy resources reduce the overall dimensions per unit of power, the operational requirement for reserve and regulating power [97][98][99][100][101] as well as the requirement for generation capacity to maintain the power system reliability [102][103][104].…”

Selecting optimum locations for co-located wave and wind energy farms. Part II: A case study

“…This model was successfully applied to examining the [20] or [21]. It computes the evolution of random waves accounting for refraction, wave generation due to wind, dissipation and non-linear wave-wave interactions [22].…”