Geothermal energy stands as another option in Australia's future energy mix. The recent first-release of steam at a hot rock geothermal well in South Australia was significant in the development of the technology and resource.One of the major players in geothermal energy in Australia, Panax Geothermal, recently announced on its website that one of its wells near Penola, South Australia, produced steam as part of a successful short flow test.This operation taps the geothermal energy of the Otway basin.

“A significant amount of steam was released after production flows to surface reached boiling point temperatures of 100 Celsius,” said Managing Director Dr de Graaf. “At this stage, it is too early to draw any conclusions on the quality of the reservoir but completion of the scheduled short flow test brings the Penola Project one further step closer to the establishment of Australia’s first geothermal reserves."

Geothermal energy technologies utilise the heat contained within the earth’s crust. It holds vast potential for clean energy, particular in Australia which contains some of the largest non-volcanic hot rock resources in the world. Geoscience Australia is responsible for mapping in detail this massive resource for improved exploitation.

Estimates and statements on the potential of geothermal in Australia vary, although they are always massive. Geoscience Australia estimates that 1% extraction of the heat contained in the top 5 km of the Australian resource would be enough power for 26,000 years at 2005 usage levels. Meanwhile, a study by the ANU says the most favoured source of hot granite rocks would provide 800 years of supply in Australia.

Of course, utilisation is subject to technology development and hot rocks are at a relatively early stage. Virtually all of the world’s 10 GW installed geothermal capacity centres around volcanic-origin conventional sources such as in Iceland, New Zealand and Indonesia. While resource is massive, the technology to generate and deliver to market economically is still a while away.

In ABARE’s latest long-term energy projections, geothermal electricity generation in Australia is projected to increase by 18.4 per cent per year, to reach around 6 TWh in 2029–30 and account for around 1.5 per cent of total electricity generation.

Source: Australian Coal Association