Speaking at the 2006 Paydirt SA Resources and Energy Investment Conference today, PIRSA director of petroleum Barry Goldstein said 11 companies have so far applied for a total of 76 geothermal licences (GELs) covering more than 35,000 square kilometres in the state.
“Whilst it may not eventuate, the aggregate investment for work programs in these GELs over the next five years is estimated to be more than $438 million,” Goldstein said.
“That is an estimate that excludes any demonstration plants or up-scaling work on the road to commercialisation.”
Goldstein said there was a lot of exploration interest in South Australia’s geothermal energy belt, which includes most of the eastern part of the state, with a particular focus in the far northeast.
He added that, when plotted as carbon dioxide emissions per megawatt hour and electricity generation costs per megawatt hour, geothermal energy costs about $60 per megawatt hour to produce – placing it ahead of nuclear power.
“Just one GEL has the hot rock emission-free energy potential to yield electricity equivalent to several Snowy Mountain hydro-electricity schemes,” Goldstein said.
Hot dry rock (HDR) exploration and production relies on exploiting hot granite rock trapped beneath layers of insulating rock no more than 5km below the earth's surface. The heat in such “reservoirs” can reach more than 250C.
Generating useable energy from hot rocks involves drilling two parallel wells. Water will be pumped down one well at extremely high pressure, passing through fractures in the granites. The super-heated water would then be transferred up via a second well to a power station to generate steam and then electricity.
Over the last couple of years, developments in this small and relatively new industry has been dominated by three publicly listed companies, Geodynamics, Petratherm and Green Rock Energy.
However, new players, including Havilah Resources spin-off Geothermal Resources, and Eden Energy, have recently listed on the ASX to raise funds for exploration in their South Australian permits.
