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Who remembers “hot dry rocks” and Geodynamics? No?

How about the drilling of Australia’s deepest onshore well at the time, Jolokia-1 in 2008, a record that was only beaten in 2019?

The great geothermal “boom” of the second half of the 2000s promised so much but delivered so little (similar to carbon capture and storage really).

There was a frenzy to secure geothermal exploration permits as a number of Australian companies, even Woodside for a short time, rode the wave of a promise of endless energy from the Cooper Basin’s deep geothermal resources.

So what happened? A small amount of power was produced at great cost, drilling was extremely expensive and technically difficult, and markets were too far away.

The dream evaporated, as geothermal energy in Australia was put in the too hard basket and the companies involved disappeared or turned to other opportunities. (Geodynamics survives to this day as hydrogen hopeful ReNu Energy.)

Now a new wave of explorers is attempting to revive the geothermal energy dream.

The company that drilled the well that went deeper than Geodynamics’ Jolokia-1, ASX-listed Strike Energy, has put forward plans to tap into a geothermal resource in the Perth Basin where it has exploration permits covering 3500km2.

Strike has built up knowledge of the geothermal resource from its proximate deep gas wells and is planning a new test well, Future State-1, to test the geothermal potential of the area.

Its modelling so far is predicting water-wet sandstones that could flow water at 175°C to support up to 350 MW of power generation.

This week another resources explorer, ASX-listed Greenvale Mining (planning to become Greenvale Energy), has turned towards geothermal energy.  

Greenvale acquired an initial 51% interest in private geothermal energy company Within Energy, which is developing projects within three Queensland permits near Brisbane, Maryborough and Gladstone.

Within Energy is targeting shallow geothermal resources adjacent to volcanic basalt formations found east of the Great Dividing Range. Binary Rankin heat exchanger technology will be used to exploit the lower temperatures compared with the deep Cooper Basin hot dry rock granites.

Greenvale is also factoring in a successful project’s potential eligibility for both carbon credits and renewable energy certificates, as no doubt Strike will be.

While still yet to be proven, the new wave of geothermal projects in Australia are far removed from their scope and scales from the heroics of the Cooper Basin hot dry rocks explorers.