Geoscience Australia and the Australian Bureau for Agriculture and Resource Economics recently undertook an initiative, The Australian Energy Resource Assessment study, at the request of the Australian government’s Department of Resources, Energy and Tourism.
The initiative was taken to examine the nation’s identified and potential energy resources.
It has been highlighted that ocean energy technologies are still at an early stage of development and have only been used at a pilot scale in Australia.
Adoption of ocean energy in Australia depends on technologies for tidal or wave energy proving commercially viable. The cost of access to the transmission grid may also be an impediment for many sites.
The northern half of the Australian continental shelf has limited wave energy resources. The southern half of the Australian continental shelf has world-class wave energy resources along most of the western and southern coastlines, particularly the west and southern coasts of Tasmania.
Many of Australia’s best tidal and wave energy resources are in areas distant from the electricity grid. The proximity of the resource to major population centres and the electricity grid appears to be somewhat better for wave energy than tidal or ocean thermal energy.
The states with the best wave energy resource are Western Australia, South Australia, Victoria and Tasmania. Tasmania is particularly well endowed with wave energy resources. There are locations off its coast where the average wave power in water depths less than or equal to 50m reach almost 35 kW/m, delivering a total wave energy of 1100 GJ/m annually.
Four tidal or wave energy plants, with a combined capacity of less than 1 MW, have been developed in recent years.
There are also plans to develop several commercial scale tidal and wave energy projects in Australia. If successful, these projects could lead to commercial scale plants generating electricity for the grid, for off-grid local domestic and industrial use, or to power water desalination plants.
The global wave power resource in deep water (100 m or more) has been estimated at 1–10 TW and the economically exploitable resource could be as high as 2000 TWh per year (WEC 2007). The average annual wave power across the world is shown in figure 11.4. Some of the coastlines with the greatest wave energy potential are the western and southern coasts of South America, South Africa and Australia. These coasts experience the waves generated by the westerly wind belt between latitudes 40° and 50° south, which are blowing over an effectively infinite fetch. This produces some of the largest and most persistent wave energy levels globally.
Assessment
The wave energy resource assessment presented is based on wave data hindcast by the Bureau of Meteorology at 6-hourly intervals over an 11-year period from 24090 locations evenly distributed over Australia’s entire continental shelf (Hasselmann et al. 1988).
Several types of wave energy converters are presently available to generate electricity. The choice of converter technology places limits on the locations from which wave energy can be harvested. For example, the Pelamis device is capable of generating electricity in water depths of 60 to 80 metres, whereas CETO is suited to shallower water depths (15 to 50 metres). Given these considerations, and the transmission losses expected if a wave energy converter is too far from shore, this resource assessment is restricted to the wave energy present on Australia’s continental shelf. The shelf is defined here as water depths less than 300 metres.
The northern Australian shelf (i.e. above latitude 23 degrees south) is characterised by relatively low wave energy densities of generally less than 2.5 kJ/ m². The southern Australian shelf, on the other hand, is characterised by energy densities of more than 2.5 kJ/ m², with large areas of the shelf experiencing twice this value (e.g. western and southern Tasmania). Much of the southern Australian coastline experiences significant wave heights (in excess of 1 m) virtually all of the time.
The total wave energy on the entire Australian continental shelf at any one time, on average, is about 3.47 PJ.
Read more:
Australia: http://social.waveenergytoday.com/search/node/Australia
Victoria: http://social.waveenergytoday.com/search/node/Victoria
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