Australasian Science: Australia's authority on science since 1938

Fresh Water Using Geothermal Heat

By Hal GurGenci

Geothermal heat can provide cheap fresh water to homesteads and small townships in the outback by removing salt from brackish aquifers.

Hal Gurgenci is a Professor of Mechanical Engineering at the University of Queensland, and the Director of the Queensland Geothermal Energy Centre of Excellence, which was established last year by a $15 million grant from the Queensland government.

The full text of this article can be purchased from Informit.

Water is essential for life. Living in the driest continent on Earth, Australians probably know this better than anyone else. Most of our large cities are currently subject to water restrictions. Large-scale desalination plants are already operating in Perth and Brisbane; Sydney is building one bigger than those two and Melbourne has plans to build the biggest.

These plants use reverse osmosis technology. This essentially involves pumping the salty water through membrane filters that trap the salt and pass only freshwater.

Reverse osmosis is popular but it is not the only way to desalinate water. In fact, only 40% of the world’s desalinated water comes from reverse osmosis plants. About 50% is produced by thermal desalination and the remaining 10% by other means or hybrid systems.

Thermal desalination is preferred wherever there is access to cheap heat. The world’s largest desalination plants are thermal desalination plants using waste heat from large combined-cycle gas turbine facilities built in the oil-producing countries of the Middle East, such as Saudi Arabia’s Shuaiba III desalination plant (Fig. 1).

Recent studies indicate that Queensland has ample geothermal resources. There are two types of resources:

• the deep hot fractured rock resources of the Cooper, Eromanga and Drummond basins; and

• the hot sedimentary...

The full text of this article can be purchased from Informit.