Like many of the basins along Australia's eastern seaboard, there is currently only a limited understanding of the geothermal energy potential of the New South Wales extent of the Clarence-Moreton Basin. To date, no study has examined the existing geological information available to produce an estimate of subsurface temperatures throughout the region. Forward modelling of basin structure using its expected thermal properties is the process generally used in geothermal studies to estimate temperatures at depth in the Earth's crust. The process has seen increasing use in complex three-dimensional (3D) models, including in areas of sparse data. The overall uncertainties of 3D models, including the influence of the broad assumptions required to undertake them, are generally only poorly examined by their authors and sometimes completely ignored. New methods are presented in this study which will allow estimates and uncertainties to be addressed in a quantitative and justifiable way. Specifically, this study applies Monte Carlo Analysis to constrain uncertainties through random sampling of statistically congruent populations. Particular focus has been placed on the uncertainty in assigning thermal conductivity values to complex and spatially extensive geological formations using only limited data. As a case study these new methods are then applied to the New South Wales extent of the Clarence-Moreton Basin. The geological structure of the basin has been modelled using data from existing petroleum drill holes, surface mapping and information derived from previous studies. A range of possible lithological compositions was determined for each of the major geological layers through application of compositional data analysis. In turn, a range of possible thermal conductivity values was determined for the major lithology groups using rock samples held by the NSW Department of Primary Industries (DPI). These two populations of values were then randomly sampled to establish 120 different forward models, the results of which have been interpreted to present the best estimate of expected subsurface temperatures, and their uncertainties. These results suggest that the Clarence-Moreton Basin has a moderate geothermal energy potential within an economic drilling depth. This potential however, displays significant variability between different modelling runs, which is likely due to the limited data available for the region. While further work could improve these methods, it can be seen from this study that uncertainties can provide a means by which to add confidence to results, rather than undermine it.

The Geoscience Australia (GA) building located in Symonston, ACT utilises one of the largest GSHP systems in the southern hemisphere. It is based on a series of 210 geothermal heat pumps throughout the general office area of the building, which carry water through loops of pipe buried in 352 bore holes each 100 metres deep and 20cm in diameter. The system is one of the largest and longest operating of its type in Australia, providing an opportunity to examine the long term performance of a GSHP system. A 10-year building review conducted in 2007 estimated that the system had saved about $400,000 in electricity costs. When comparing energy performance in the annual 'Energy Use in the Australian Government Operations' reports, the GA building has maintained energy performance and targets that might normally be expected of a general office administration building. This is significant given the requirements to provide additional fresh air to laboratories and 24/7 temperature control to special storage areas. The energy savings can be attributed to the GSHP system and other energy efficient design principles used in the building.

This presentation was delivered at the 30th NZ Geothermal Workshop in Taupo, New Zealand (10 - 13th November 2008). It summarises the key initiatives the Australian Government and State Governments have in place to support the growth of Australia's young geothermal industry.

Legacy product - no abstract available

Educational factsheet summarising geothermal systems (hydrothermal and Hot Rock systems), advantages of geothermal power generation in Australia, geothermal power generation systems, and future electricity generation in Australia using geothermal energy. The mini-abstract on the factsheet is as follows: Geothermal energy is the heat contained within the Earth and it can be used to generate electricity by utilising two main types of geothermal resources. Hydrothermal resources use naturally-occurring hot water or steam circulating through permeable rock, and Hot Rock resources produce super-heated water or steam by artificially circulating fluid through the rock. Electricity generation from geothermal energy in Australia is currently limited to an 80kW net power plant at Birdsville in south west Queensland. However this is likely to change in the future as Hot Rock power plants become increasingly commercially viable.

Examination of developing geothermal exploration techniques and a geothermal play systems framework in Australia.

This dataset represents the results of the assessment of the potential for uranium and geothermal energy systems in the southern Northern Territory. Four uranium systems were targeted: 1) sandstone-hosted, 2) uranium-rich iron oxide-copper-gold, 3) unconformity-related, and 4) magmatic-related. These were assessed for using a 2D, GIS-based approach, and utilised a mineral systems framework. In addition to the uranium systems investigated, the potential for hot rock and hot sedimentary aquifer geothermal systems was also assessed. Only the results of the hot rock geothermal assessment are presented here, since the assessment for hot sedimentary aquifer geothermal systems is more qualitative in nature. The assessment for hot rock geothermal systems was undertaken in a 3D environment, with temperatures at depth predicted using the 3D GeoModeller software package.

Work at the Bureau of Mineral Resources (now Geoscience Australia) in the early 1990s was instrumental in bringing hot rocks geothermal research and development to Australia. The Energy Initiative of the Federal Government, announced in August 2006, has restarted a geothermal project in GA. This paper outlines the scope of the Onshore Energy Security Program, the development and implementation of the new Geothermal Energy Project, and progress to date. The Onshore Energy Security Program A program to acquire pre-competitive geoscience information for onshore energy prospects has begun following the Prime Minister's Energy Security Initiative. The initiative provides $58.9 million over five years to Geoscience Australia for the acquisition of new seismic, gravity, geochemistry, heat flow, radiometric, magneto-telluric and airborne electromagnetic (EM) data to attract investment in exploration for onshore petroleum, geothermal, uranium and thorium energy sources. The program will be delivered in collaboration with the States and Territory under the existing National Geoscience Agreement. A set of principles have been developed to guide the program. According to the principles, proposed work must: promote exploration for energy-related resources, especially in greenfields areas; improve discovery rates for energy-related resources; be of national and/or strategic importance; and data acquisition must be driven by science. The program is structured with national-scale projects for each energy commodity (geothermal, petroleum, uranium and thorium) and for geophysical and geochemical acquisition. Regional scale projects in Georgetown-Isa, Gawler-Curnamona, Northern WA and the Northern Territory areas will assess the energy potential of those areas in detail. Other regions will be prioritised at a later stage of the OESP. Formulating the Geoscience Australia Geothermal Energy Project Based on consultation with State and Territory geological surveys and geothermal exploration companies, a list of the impediments faced by geothermal companies was identified. The Geothermal Energy Project addresses those that require geoscience input. The greatest geological problem facing explorers is a lack of understanding of the distribution of temperature in the upper crust of Australia. The two existing datasets that map temperature and heat distribution - the Austherm map of temperature at 5 km depth, and a database of heat flow measurements - both require a great deal of infilling. It is also possible to make predictive maps of expected heat based on geological models. These three ways of mapping heat, and the work that the project will do in each of these areas, is described in more detail in later sections. Other geoscience inputs that will help improve discovery rates and/or reduce risk to explorers and investors include a comprehensive and accessible geothermal geoscience information system, a better understanding of the stress state of the Australian crust, better access to seismic monitors during reservoir stimulation, and a Reserve & Resource definition scheme. Increasing the awareness of Australia's geothermal potential amongst decision makers and the general public may also help the funding of the development of the industry through Government support and investor confidence. The Geothermal Project has involvement in all of these activities, as outlined in later sections.

The Oceania region encompasses a range of geothermal environments and varying stages of geothermal development. Conventional geothermal resources in New Zealand, Papua New Guinea, Indonesia and the Philippines have been used for power generation for as long as 50 years, whereas Australia's non-conventional 'Hot Rock' geothermal resources have only recently been targeted as an energy source. New Zealand's geothermal resources are high-temperature convective hydrothermal systems associated with active magmatism, and these have been exploited for electricity generation since 1958. With a total installed capacity of ~445MWe, geothermal energy currently generates ~7% of New Zealand's electricity. This figure is likely to increase in response to the New Zealand Government's recent target of 90% of the country's electricity to be generated from renewable resources by 2025. Geothermal power plants used in New Zealand are either condensing steam turbines, or combined-cycle plants that utilise a steam turbine with binary units. In terms of energy consumed, direct-use of geothermal energy rivals electricity generation at approximately 10,000 TJ/yr. Applications include industrial timber drying, greenhouse warming and aquaculture, and may be stand-alone or cascading. Analogous high-temperature hydrothermal systems elsewhere in Oceania support installed electricity generation capacities of 56MWe in Papua New Guinea, 838MWe in Indonesia and 1931MWe in the Philippines. In contrast, Australia's geothermal plays are principally associated with high-heat-producing basement rocks. Typically these rocks are granites that are relatively enriched in the radioactive elements U, Th and K and thus have elevated heat generation (i.e. >6µW/m³). Elevated temperatures are found where this heat is trapped beneath sufficient thicknesses (>3km) of low-thermal-conductivity sediments. Low-temperature hydrothermal systems can be found in shallow aquifer units that overlie the hot basement. Hot Rock geothermal plays are typically found at greater depths (3 to 5km), where temperatures in the basement itself or in overlying sediments can exceed 250°C. Electricity can be generated from Hot Rock resources by artificially enhancing the geothermal system (e.g. increasing rock permeability at depth by hydro-fracturing). Although no electricity has yet been generated from Australia's Hot Rocks, a listed company (Geodynamics Ltd) has completed two 4200m-deep wells in the Cooper Basin, and expects to establish a 1MWe pilot plant by late-2008, a 50MWe plant by 2012, and 500MWe by 2015. As of January 2008, there are 33 companies in Australia prospecting for Hot Rock and hydrothermal resources, across 277 license-application areas that cover 219,00km². In support of industry exploration, and to increase uptake of geothermal energy in Australia, Geoscience Australia is currently compiling and collecting national-scale geothermal datasets such as crustal temperature and heatflow.

This report is a formal release of 12 new heat flow determinations made by Geoscience Australia. These new data are located in WA, NSW and Tasmania, and add to the 41 heat flow determinations previously released under the Onshore Energy Security Program.