Authors / CoAuthors
Ayling, B.F. | Harvey, C.C.
Abstract
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.
Product Type
nonGeographicDataset
eCat Id
65686
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
-
- External PublicationAbstract
- ( Theme )
-
- geothermal
- ( Theme )
-
- Hot Rocks
-
- AU
- Australian and New Zealand Standard Research Classification (ANZSRC)
-
- Earth Sciences
-
- Published_Internal
Publication Date
2008-01-01T00:00:00
Creation Date
Security Constraints
Legal Constraints
Status
Purpose
Maintenance Information
unknown
Topic Category
geoscientificInformation
Series Information
Lineage
Unknown
Parent Information
Extents
[-44.0, -10.0, 112.0, 155.0]
Reference System
Spatial Resolution
Service Information
Associations
Source Information
Source data not available.