Australia’s vast hydrothermal and hot rock energy resources have the potential to become a very significant source of safe, secure, competitively-priced, emissions-free, renewable baseload power supplies for centuries to come. That potential, plus evidence of risks posed by climate change, are factors stimulating growth in geothermal energy exploration, proof-of-concept and demonstration power generation projects in Australia.
In the six years since the grant of the first Geothermal Exploration Licence (GEL) in Australia in 2001, 19 companies have joined the hunt for renewable and emissions-free geothermal energy resources in 143 licence application areas covering approximately 149,000 km2.
The associated work programs correspond to an investment of more than
$650 million. Figure 1 illustrates investment through 2007. Additional investment will be required for up-scaling and deployment projects. The Energy Supply Association of Australia expects that by 2030 geothermal resources will provide 6.8 per cent (~5.5 GWe) of Australia’s baseload power.
Most investment is focused on hot fractured rocks (HFR) that are amenable to hydraulic fracture stimulation to improve geothermal reservoir characteristics and create enhanced geothermal systems (EGS). At least two companies focus on hydrothermal resources though more are expected to join in that hunt. Both HFR and hydrothermal resources can fuel closed-loop, binary power plants to minimise water losses while producing emissions free power that can operate on a 24/7 basis.
In a global market with carbon pricing, geothermal energy is likely to be a significant growth industry. The anticipated cost of EGS energy in Australia has been estimated at $49-$60 per MWh (Figure 2). Without carbon pricing, many forms of conventional energy generation such as coal and natural gas are more cost effective.
Geoscience Australia’s preliminary work suggests Australia’s hot rock energy at a minimum temperature of 150ºC and at a maximum depth of 5 km is roughly 1.2 billion PJ (roughly 20,000 years of Australia’s primary energy use in 2005), without taking account of the renewable characteristics of hot rock EGS plays. A national EGS resource assessment, a CoAG road-map for the commercialisation of Australian EGS and a Federal Government’s Geothermal Industry Development Framework are expected to be published in 2008.
Barry is the Petroleum and Geothermal Group’s South Australian Director and has 27 years international experience in the energy sector. He holds Geology degrees from the University of New York (BA-75) and the University of Missouri (MA-77), and is Australia’s Executive Committee Representative to the International Energy Agency’s Geothermal Implementing Agreement. Barry is a past President of the Petroleum Exploration Society of Australia (PESA) and serves on the Boards of PESA (since 2001), the Australian Geoscience Council (since 2004), the Federation of Australian Scientific and Technologic Societies (since 2004) and the Australian School of Petroleum (since 2002). Barry was Chief Geologist with three E&P companies: Santos (1996 – 2001), Bridge Oil (1987 – 1995), and the Kuwait Foreign Petroleum Company (1982-86), after starting his career with Phillips Petroleum (1976 – 1981).