Conventional energy sources such as oil, gas, coal and nuclear can do the job at a far cheaper price and more reliably than via geothermal heat extracted from deep beneath the earth’s surface.

Even wind, solar and wave power will expose hot rocks as a fad that will fade as fast as the money runs out – which is precisely what is happening as the world’s energy-cost barometer, the price of crude oil, refuses to rise to the heights predicted by the Peak Oil lobby.

Only with a sky-high oil price that Peak Oil might deliver could geothermal be an industry worthy of investment.

This is a fact one of Australia’s most diversified energy companies, Origin Energy, has just acknowledged by withdrawing from its Innamincka joint venture with hot rocks pioneer Geodynamics.

Walking away from the latest deep test well, the Habanero No 4 – designed to extract super-heated water and then pass the associated steam through a power-generating turbine – was an easy decision for Origin which had already opted to not participate in the 2013 JV works program.

However, the message sent by Origin’s exit is one that should reverberate through the ranks of investors and the highest level of the Australian government which has been tipping a huge amount of taxpayer’s funds into hot rock technology, with no sign of ever getting a return and long before the price-depressing shale-gas revolution rolls across the energy sector just as it has done in the US.

As the geothermal game stands there are so many losers that The Slug is not sure where to start so, in keeping with a deep-seated interest in money, let’s give hot rocks a boot where it hurts most, in the wallet of investors.

Geodynamics, for example, is the Australian hot rocks pioneer.

It did a spiffing marketing job a decade ago, raising millions of dollars to try and prove the geothermal energy theory in central Australia.

At one stage towards the end of 2007 the company’s shares traded up to $2.09, before commencing their long slide to the edge of darkness, which is where they are now at 7.4c, a 96% crash.

Other hot rock stocks have not done much better.

Petratherm, which hit a peak of $1.37 in mid-2007 is trading at 2.3c, a 98% plunge for some unfortunate believer in hot rock power.

However, the person who really deserves to be in the cross hairs is the recently resigned energy minister Martin Ferguson.

He signed off on a huge taxpayer investment in geothermal and other trendy energy research programs, which seemed like a good idea at the time – well, at least they seemed good to dark green environmentalists but not The Slug.

In a press statement on November 6, 2009, which should never be forgotten, Ferguson said the Australian government would award “$235 million to four commercial-scale renewable energy projects from the renewable energy demonstration program” – with Geodynamics to get a $90 million grant.

If you forget the fact that Geodynamics today is a company valued on the stock market at just $30 million there is something even more interesting in Ferguson’s 2009 announcement – that the government funding, combined with money from successful applicants, will (yes, will) deliver “almost 80 megawatts of new renewable generation” – from a variety of sources, including geothermal.

At the time of that statement The Slug went ballistic because Ferguson’s promise that taxpayer funds would lead to a major new source of energy was made at the same time the Australian government was prosecuting iron ore magnate Andrew Forrest for a famous comment about a “binding” deal with Chinese investors.

In hindsight, it seems Forrest’s forecast for his Fortescue Metals Group (which caused him to be hounded through the courts for five years) has produced a better outcome than the government’s own forecasts for 80MW of power that “will” be delivered from its investment in renewable schemes.

It will get worse because Origin’s withdrawal comes just as it – and many other companies – are taking a serious interest in the new game in Australia’s energy equation – shale gas.

No one is predicting a shale gas boom similar to that which has occurred in the US – yet – because Australia lacks the same market depth and pipeline system.

For geothermal hopefuls, who believed a commercially viable industry based on hot rocks could be developed, the future is grim as one-time believers such as Origin beat a discreet retreat.