Geothermal Energy Resources

Geothermal energy is an emerging industry in Australia, with exploration being conducted in all states and the Northern Territory. While significant resources have been identified and there are several companies in advanced stages of exploration, presently there is no commercial production of geothermal energy in Australia. That said, there is significant potential for geothermal energy in Australia. It is estimated that one per cent of the geothermal energy shallower than five kilometres and hotter than 150°C could supply Australia’s total energy requirements for 26 000 years (based on 2004-05 figures).

Geothermal energy uses

Geothermal energy is heat contained within in the earth. Australia has great potential for geothermal energy to be used for electricity generation and for direct use applications. Electricity can be generated using temperatures as low as 100°C, although higher temperatures than this may be required for larger scale production. For direct use applications, temperatures of 30°C and above can be used in industry, agriculture and for heating and cooling of residential buildings (see Fact sheet Direct-use of Geothermal Energy Opportunities for Australia).

Geothermal energy exploration

Temperature logging system

Currently drilling technology limits economic development of geothermal resources to a maximum depth of about five kilometres. Thus companies are exploring for regions of elevated temperatures at five kilometres deep or less. The temperature at five kilometres depth varies across the continent due to a range of geologic factors. It is possible to identify areas of higher potential through the use of a variety of geoscience data.

Geoscience Australia programs

Geoscience Australia is undertaking significant work to better understand where these hot spots are in order to support the geothermal industry and encourage exploration in Australia. As part of the federal government’s Onshore Energy Security Program, a field logging program has been set up with the aim of improving the heat flow coverage of Australia. Heat flow is determined by taking the product of thermal conductivity and temperature gradient in a borehole and can be used to predict temperatures at greater depths. Geoscience Australia has released the first set of Heat flow interpretations for the Australian Continent.

Another product that has been released is the OZTemp database. This has been generated using temperature measurements from a variety of sources and extrapolating these to five kilometres depth. The extrapolated temperature can be horizontally interpolated between drillholes, and then contoured to produce a continuous map of temperature at five kilometres depth across the entire continent. This technique was pioneered by Somerville et al. (1994 - Geotherm94 database) at the Bureau of Minerals Resources (now Geoscience Australia) and the Energy Research and Development Corporation External site link. The database and the image for the current iteration are available on their website.

Geoscience Australia has also been involved in the development of the Geothermal Reporting Code External site link, a geothermal reserves definition scheme similar to the minerals-based Joint Ore Reserves Committee (JORC) code and petroleum-based SPEE scheme. This was produced in collaboration with the Australian Geothermal Energy Group (AGEG) and the Australian Geothermal Energy Association (AGEA) External site link and is critical to the large-scale development of the geothermal industry. In addition, Geoscience Australia has collaborated with the Department of Resources, Energy and Tourism (RET) External site link and AGEA to develop the Australian Geothermal Industry Development Framework and Technology Roadmap External site link with the aim of assisting geothermal exploration in Australia.

 

 

 

 

 

 

 

Table 1: Listing of Geothermal Reporting Code-compliant Resources in Australia
Project Location State Company Inferred
Resource
(Petajoules)
Inferred
Resources –
Uncertainty
(+/- PJ)
Indicated
Resource
(Petajoules)
Measured
Resource
(Petajoules)
Play
Type
ASX
Report
Date
Parachilna
Geothermal
Play
150km north
of Port Augusta
South Australia Torrens
Energy
780 000 70 000     EGS 15.08.2008
Olympic Dam
Geothermal
Energy Project
Olympic
Dam, SA
South Australia GreenRock
Energy
116 770       EGS 27.08.2008
The Cooper Basin
Project
Innamincka South Australia Geodynamics 230 000   7600 1800 EGS 21.10.2008
Anglesea
Geothermal Play
Geelong Victoria Greenearth
Energy
220 000 40 000     EGS 4.12.2008
Paralana
Geothermal Play
Flinders Range South Australia Petratherm 230 000 40 000     EGS 20.12.2008
Wombat
Geothermal Play
Gippsland Victoria Greenearth
Energy
3600 800     HSA 5.01.2009
Limestone Coast
Project: Rendelsham
Geothermal
Play
Mt Gambier South Australia Panax 17 000       HSA 21.01.2009
Limestone Coast
Project:
Rivoli-St Clair
Geothermal Play
Beachport South Australia Panax 53 000       HSA 21.01.2009
Limestone Coast
Project: Penola
Geothermal Play
40km north
Mt Gambier
South Australia Panax 89 000   32 000 11 000 HSA 18.02.2009
Limestone Coast
Project: Tantanoola
Geothermal Play
Northwest
Mt Gambier
South Australia Panax 130 000       HSA 31.03.2009
Roxby
Geothermal Project
40km north
Port Augusta
South Australia Southern Gold 260 000       EGS 2.06.2009
Tirrawarra
Geothermal
Project
Moomba South Australia Panax 34 500   30 000 11 000 HSA 07.07.2009
Frome Project Frome Basin South Australia Geothermal
Resources
84 000       EGS 13.07.2009
Lemont
Geothermal Play
Midlands
Area
Tasmania KUTh Energy 260 000       EGS 14.07.2009
Perth Permit Metropolitan Perth Western Australia GreenRock
Energy
29 960       HSA 28.07.2009
Geelong
Geothermal Power
Project
Geelong Victoria Greenearth
Energy
17 000       HSA 17.08.2009
Nicholas-Fingal
Geothermal Play
Fingal Valley Tasmania KUTh Energy 101 000       EGS 9.03.2010
Port Augusta
Project Area
Port Augusta South Australia Torrens
Energy
70 000       EGS 15.11.2010
Total Resource          2 725 830 158 000 69 600 23 800      

Topic contact: energy@ga.gov.au Last updated: April 10, 2013