| Abstract |
Hot Rocks (HR) have potential to fuel competitive, emission free and renewable electricity for centuries to come. This potential is stimulating Enhanced (Engineered) Geothermal Systems (EGS) projects worldwide, calling upon integrated expertise from the petroleum, minerals and power industries. Converting just 1% of Australia’s estimated HR crustal energy to electricity, from a minimum temperature of 150°C and to a maximum depth of 5 km (190 million PJ, equivalent to 52,777,778 TWh) would supply about 26,000 years of Australia’s primary power use, and that neither takes into account the renewable characteristics of HRs, nor resources below 5,000m. Factors that distinguish Australian HR are: (1) relatively high, 92mWm-2 average heat flow over large areas compared to a global continental average of 51mWm-2; and (2) Australia is converging with Papua New Guinea on a plate scale – giving rise to common, naturally occurring sub-horizontally fractured basement rocks that are susceptible to hydraulic fracture stimulation. Australia’s geothermal projects are focused on both HR to develop EGS and associated Hot Sedimentary Aquifer (HSA) plays to fuel binary power plants. In addition to meeting demand for base load power, mining, desalinisation and drying processes are also markets for geothermal energy. In the term January 2000 through December 2008, companies have applied for 383 licence areas (covering 358,400 km2) to progress proof-of-concept amagmatic HR and HSA projects in Australia. In the term 2002 through 2008, more than Aus$325 million (US$260 million)1 has been spent on studies, geophysical surveys, drilling, reservoir stimulation and flow tests that comprise the work programs required to sustain tenure in geothermal licences areas. In the term 2002-2013, investment for Australian proof-of-concept geothermal projects is expected to exceed Aus$1,523 million (US$1,218 million). This rapidly rising level of investment is driving sector-wide cooperation to support high priority and complementary research that can speed the pace and lower the cost of commercialising Australia’s vast HR and HSA geothermal plays. That cooperation is underpinned with more than Aus$114 million (US$91 million) in Australian Federal and State government grants to meet up to half of the cost of the private sector’s field efforts. This includes Aus$60 million (US$48million) available to support new deep drilling for the proof-of-concept HR and HSA projects, but excludes Aus$587 million (US$470 million) for all forms of meritorious, pre-competitive, commercial-in-scale, sustainable ocean, geothermal and biomass energy projects. These collateral efforts are all directed at having at least 10 successful research and proof-of-concept geothermal projects by the middle of 2013, and at least 3 power generation demonstration projects in distinctly different geologic settings by the end of 2013, with the results providing compelling evidence to justify investment in the development of Australia’s vast HR and HSA plays. Success in Australia will have positive implications for similar projects, world-wide. Given success in current proof-of-concept projects, subsequent demonstration projects, and adequate commercial drivers, it is reasonable to expect sustainable and emissions-free geothermal energy to fuel at least 5.5 GWe of Australia’s base-load power by 2030 and at least 10 GWe by 2050. |