The wave energy resource along Australia’s Southern margin

Abstract

The Southern Australian margin is one of the most energetic regions in the world suitable for the extraction of wave energy for electricity generation. We have produced a data set in which the deep-water wave energy resource for the region is described by three representative deep-water wave states, equivalent to the 10th, 50th, and 90th percentiles of the deep-water wave energy flux, derived from archives of the USA National Oceanic and Atmospheric Administration (NOAA) WaveWatch III (NWW3) operational wave model. The Simulating WAves Nearshore (SWAN) wave model is then applied along the full Southern Australian margin to propagate these representative wave states into the near-shore region to quantify the effects of shallow water processes such as refraction, shoaling, and bottom friction. The wave energy incident on the 25-m isobath (∼30–50 kW/m) is approximately 35%–50% less than the World Energy Council estimates of offshore wave energy but is approximately 20% greater than the energy observed from long-term buoy deployments on the midshelf. The latter discrepancy is attributed to an overestimation of significant wave height along the Southern Australian margin by the NWW3 model. The near-shore model applied in this study adequately simulates the attenuation of wave heights across the continental shelf when compared with estimates of wave height attenuation obtained from the Topex satellite altimeter. The attenuation of wave energy across the continental shelf reduces the estimates of offshore wave energy as given by the World Energy Council; however the wave energy resource incident on the Southern Australian margin remains considerable. We estimate that if 10% of the incident near-shore energy in this region, which is an ambitious target when conversion efficiency is considered, were converted to electricity, approximately 130 TW h/yr (one-half of Australia’s total present-day electricity consumption) would be produced.