http://www.theaustralian.news.com.au/story/0,25197,23424733-50052...

http://www.theaustralian.news.com.au/story/0,25197,23424733-5005200,00.html

Day of truth closer on hot rocks

Nigel Wilson, Energy writer | March 25, 2008

AUSTRALIA'S search for reliable zero-emission energy from hot rocks deep underground is approaching a crucial point.
Lighting Rig

Geodynamics' 'Lighting Rig' the largest drilling rig to come to Australia

At the weekend, long-term geothermal energy hopeful Geodynamics conducted flow tests on its Habanero wells near Innamincka in South Australia.

The company is not scheduled to report on the results until later this week, but the Cooper Basin project is now well advanced after years of technical difficulties.

Geodynamics managing director Gerry Grove-White takes a realistic view, conscious of the disappointments flowing from past hype.

"It has been a long wait but we are making real progress," he said before last weekend's flow test program.

Having established a robust hydraulic link between the Habanero-1 and Habanero-3 wells, the tests are designed to assess whether there is a pressure drop between them.

This, and whether the temperature falls significantly, will be important in deciding whether it is feasible to pump water down one hole into the hot granites and collect energy in the form of steam from another hole.

The company, listed in 2002, says the proof of concept will demonstrate the viability of heat extraction from the underground heat reservoir.

The geothermal reserves will be signed off by independent geothermal experts from the US.

Habanero-3 was drilled last year by Geodynamics' Le Tourneau "Lightning Rig", which can operate to depths of more than 6000m.

Geodynamics said Habanero-3, which reached a depth of 4221m in January, was the project's first commercially viable well.

Last week Geodynamics spudded the Jolokia-1 well, about 9km from Habanero, which is designed to provide information on the extent of the hot granites in the company's permit.

Geodynamics is heavily backed by Origin Energy, and Woodside is a foundation investor.

Origin has a 30 per cent stake in Jolokia-1, with the remainder held by Geodynamics. Mr Grove-White said the company would install a heat exchanger in early May, once the weekend program had been evaluated, and conduct an intensive scientific program over six to eight weeks.

That would establish data for the installation of a 1 megawatt demonstration power plant by the end of the calendar year, to run the company's operational base.

During the remainder of the year Geodynamics plans to complete its preferred design for a 50MW power plant, with the aim of having it operating commercially in 2012, producing zero-emission energy with zero water requirements.

It is expected to generate enough electricity to supply about 50,000 households continuously.

One of the medium-term drivers of the program is BHP Billiton's requirement for 800MW of electricity generation capacity to power the expansion of the Olympic Dam mine, about 490km away.

This would help overcome one of the Habanero project's implicit disadvantages -- its distance from the main transmission network.