A potential energy source in Australia is set to remain untapped, with a geothermal power project in the far north of South Australia now closed.

Energy company Geodynamics closed and remediated the sites of several test wells and generation plants in the Cooper Basin after deciding they were not financially viable.

Before the closure, the company had managed to extract super-heated water from five kilometres below the earth's surface and use it to generate small amounts of electricity.

"The technology worked but unfortunately the cost of implementing the technology and also the cost of delivering the electricity that was produced to a market was just greater than the revenue stream that we could create," Geodynamics chief executive Chris Murray said.

Professor Martin Hand ran the South Australian Centre for Geothermal Energy Research at the University of Adelaide.

"I think it was talked up too much — it's a very nice concept on the front page of a newspaper, looks very easy to do, and I think it was over-spruiked," he said.

Professor Hand said large areas of the Earth's crust across Australia were very hot and could be ideal for use as a non-conventional energy source.

"Rocks about five kilometres below the surface are at temperatures of around 240 to 250 degrees and, in principle, if water could be circulated through those rocks it could be returned to the surface to produce geothermal power in a power plant," he said.

Steam readily rises from vents in the Earth's crust in New Zealand. ( ABC News: Gary Rivett )

He pointed out Australian geothermal energy differed greatly from the energy created by abundant and accessible steam vents in countries such as New Zealand and Iceland.

"There are 46 countries around the world that generate significant geothermal energy, but all of those come from conventional systems — where you see the geysers and all the volcanic manifestation, where there is natural permeability in the ground," Professor Hand said.

Geodynamics now talks of a brighter future for bio-gas, the recycling of farm waste and methane for electricity production.

"Not only does it reduce the greenhouse gases of a facility, but it provides renewable energy," Mr Murray said.

South Australia's Conservation Council is keen to see more public investment in geothermal energy and other renewable energy sources.

"There's no doubt that a lot of these start-up, new sources of energy will require public funding to give them a start and, what we've found is, as soon as that happens the cost curve quickly reduces," chief executive Craig Wilkins said.

Professor Hand made a similar call.

"If we could see [geothermal] as some kind of national resource, and therefore it's some kind of national research project, there is a vast amount of energy that could be potentially unlocked."