Geothermal Deposits in Northern Territory

The geothermal energy industry is eyeing the Northern Territory as a key source of inexpensive and renewable energy. Susan Jeanes from the Australian Geothermal Energy Association says the introduction of the carbon tax has made it more worthwhile to invest in exploratory drilling.

Geothermal energy consultancy Hot Dry Rocks has worked with Google and hot rock experts overseas to estimate and map the planet's reserves.

The preliminary heat-flow map for Australia shows SA, Queensland and the Northern Territory have the most abundant geothermal resources in the nation - we just have to tap into the resource.

Rocks within 5km of the surface of SA could generate 58,541MW of electricity if just 2 per cent of the heat were extracted, or 585,410MW if 20 per cent of the heat were extracted.

This is up to 168 times the amount of energy currently generated by coal and gas.

HDR managing director Graeme Beardsmore says that geothermal is "clean, renewable energy that is realistically accessible today with existing drilling and power conversion technologies".

"Enhanced geothermal systems have the potential to provide base load power; it is one of the most abundant sources of renewable energy available and is more than sufficient to replace current coal and gas power supply," he said.

Geothermal electricity is produced from energy released from superheated rocks lying kilometres below the earth's surface. Ms Jeanes says drilling has already commenced in the Cooper Basin east of Alice Springs.

"What the problem for the industry is in this early exploration phase is that the rigs that we need to drill holes four and five kilometres deep cost about 50 million dollars," she said. "There's only one here in Australia and that's the rig that's owned by Geodynamics and that's currently located in the Cooper Basin. So anybody else who wants to drill a deep well has to bring one in from overseas."

Ms Jeanes says people need to embrace more clean energy sources. "The government has come and said we think this is a very important energy resource," she said.

"They've got a policy program now that's underpinned by a carbon price that will start to move some money for us. The market has to become more interested in clean energy sources. There are lot of clean energy options around but ultimately we're the only renewable energy on the horizon that is baseload."