Hydro, tidal and wave energy in Australia

The three renewable energy technologies discussed in this paper are based on water, but differ markedly in terms of the size of the available potential resource, the maturity of the associated conversion technologies, the extent to which they have been exploited to date, and the current research effort being devoted to their future development. Hydro-electricity and tidal power are both very mature technologies. The exploitation of Australia's relatively limited potential for hydro-electric development began over a century ago and the opportunities for further hydro-electric development are now very restricted. The country's significant tidal power resources, on the other hand, have not been exploited for electricity generation to date, but continual assessment of the feasibility of tidal power projects has been undertaken over the past half century. Although Australia has large ocean wave energy resources, ocean wave energy conversion technology is not yet fully commercial and no commercial wave generation plants are operating in Australia. A small number of wave energy conversion devices, however, are at the pilot testing stage. 1. Hydro-electric power Australia has few large rivers, low topographical relief and low rainfall. Relative to many other continents, the natural potential for hydro-electricity development in Australia is therefore limited. Large hydro-electric schemes nonetheless provide the vast majority of the electricity currently generated from renewable energy sources in Australia. Total installed hydro-electric generation capacity is 7577 MW, with a total average annual long-term hydroelectric output (ALTHEO) of 14,568 GWh, which represents approximately 7% of electricity supplied into main grids in 2003/04 [1]. The greatest hydro potential occurs in sites located in the island state of Tasmania and the two south-eastern states of the Australian mainland, New South Wales and Victoria. Together, these three states account for over 91% of installed generation capacity. Most of the installed capacity in NSW and Victoria forms part of the Snowy Mountains HydroElectric Scheme (table 1). Table 1. Installed hydro-electric generation capacity in Australia by state. The other state with significant capacity, Queensland, has two hydro-electric schemes in the far north of the state with a combined generation capacity of 139 MW as well as a 500 MW thermal pumped storage hydro-electric facility connected to the Brisbane’s main water supply reservoir in the south of the state. The largest hydro-electric scheme in Western Australia is a 30 MW hydro-electric plant that was retrofitted into the Ord River Irrigation scheme in the far north of Western Australia in 1997. There are also two small hydro-electric schemes in the south of the state. One of these, the 2 MW Wellington Dam hydro-power plant on the Collie River, was damaged by floods in the late 1990s and is unlikely to be brought back into service. The other is a small 100 kW scheme on the Pemberton River that was recently restored as cultural heritage restoration project. There are no hydro-electric schemes in either the Northern Territory or South Australia, although the option of using South Australia’s water supply systems as pumped storage to provide peak power has been investigated in the past.