Is geothermal the new green hydrogen? Earth’s Energy hopes so
With the state government’s green hydrogen ambitions shelved indefinitely, the CEO of an emerging geothermal company hopes his goals are more than just hot air.
If Earth’s Energy gets its way, the listed company will be the second to try and make geothermal energy generation happen with some warm rocks deep underground in South Australia’s far north.
The Perth-based company has two interests in South Australia: at Flinders West and Paralana.
The latter of the two might ring some bells for those who remember Petratherm’s South Australian geothermal ambitions.
More than a decade ago, SA-based Petratherm shelved its Paralana project after failing to secure enough funding for it. If it was established, it would’ve been the first of its kind in Australia.
Nearly 11 years on and Earth’s Energy CEO Josh Puckridge believes his firm’s approach will be different. Like Petratherm, his dreams require cash.
But with the state government’s dreams of a green hydrogen industry more or less dead in the water after the collapse of the Whyalla Steelworks in February, Puckridge reckons the time is now to give geothermal some serious consideration, he just needs investment to get it going.
Why geothermal?
It might not surprise you to learn that there are no active Australian geothermal energy plants.
We have no active volcanoes, and we’re quite far from the tectonic belt of volcanoes and earthquakes that make up the Pacific Ring of Fire.
If you take a look at Global Energy Monitor’s map of geothermal power plants you’ll see they’re largely scattered around the Ring of Fire, concentrated throughout Indonesia and the Philippines, up through Japan, and in California and Nevada near the fault line that runs along the United States west coast.
A map showing the world’s active geothermal power plants. Via Global Energy Monitor.
Geothermal makes sense in these regions because active volcanism creates high heat flows underground which can be captured.
But just because Australia lacks volcanoes, we’re not precluded from geothermal altogether.
The heat a theoretical Australian geothermal plant would use comes from hot rocks about 3km underground.
You might like
This ‘unconventional’ geothermal system needs fluid injected to stimulate the rocks to extract their heat. Geoscience Australia describes Australia’s unconventional geothermal resource potential as “considerable”.
Breakthroughs in ‘Enhanced Geothermal System’ (EGS) technology – whereby rocks deep beneath insulating sedimentary basins that have poor permeability are fractured to stimulate their heat – is one solution being explored by the likes of Earth’s Energy.
EGS has been tested in two locations in Australia, one of which Earth’s Energy has the tenement rights to: Paralana.
The Paralana project, east of the Flinders Ranges, was drilled by Petratherm but was not completed because the company was short $5 million in funds from private investors. This is despite having secured $24.5 million from government sources.
The company had hoped to generate electricity from a seven-megawatt geothermal plant to supply mining operations in the state’s north.
Though Geoscience Australia said “deep EGS reservoirs are yet to be adequately tested in Australia”, it remains optimistic.
“Significant technical developments overseas with EGS suggests that the technology may yet hold significant potential for Australia,” Geoscience Australia said.
Enter: Earth’s Energy
Earth’s Energy was formed when mineral resources firm Cradle Resources pivoted and acquired an 84 per cent stake in Australian geothermal firms Volt Geothermal and Within Energy just over a year ago. The two companies had geothermal assets in Queensland and South Australia.
Cradle then raised $6 million and changed its name before resuming trade on the ASX under the new ticker EE1 in early February 2024.
A few months later, Josh Puckridge was appointed CEO of the newly named firm.
Perth-based Puckridge has prior experience in the geothermal industry and was founder and managing director of Steam Resources which holds the world’s largest portfolio of prospective geothermal exploration sites.
At the time, Puckridge said EE1 was “strongly positioned to lead Australia in advancing the nation’s geothermal energy production via new technologies and practices that have been refined around the world over the last 10 years”.
It hopes to achieve this at Paralana – the aforementioned site that was abandoned by Petratherm.
But new tech, such as that being pioneered in the United States, gives EE1 some hope.
EGS works by introducing liquid to the hot rocks to build pressure and turn it into steam, generating electricity as the steam cools. The newly cooled liquid is then re-injected back into the well to repeat the cycle.
A utility scale EGS development is currently underway by a company called Fervo Energy. It’s using the modern method of horizontal drilling to increase the heat and pressure build up in the reservoir.
Speaking to InDaily, CEO Puckridge said Fervo Energy’s formation changed the game for EGS.
“They were basically a bunch of oil and gas guys who looked at geothermal and said: ‘This hasn’t had a technology upgrade. We can add value here.’,” he said.
“That big development was similar to the shale gas revolution in the USA where there was just a whole different way of looking at it.”
Since then, Puckridge said new technology enabled things like subsurface mapping which gives firms like Earth’s Energy more confidence in their approach.
Earth’s Energy CEO Josh Puckridge. Photo: Supplied
Stay informed, daily
“What’s amazing is when Paralana was originally drilled – this is like a $20 million project – they still didn’t have 100 per cent confidence that they were going to intersect where they wanted to intersect, and now we do,” Puckridge said.
Also, the cost of drilling has come down, plus the movement towards horizontal drilling has made the projects more financially viable as they can generate more electricity.
“It’s definitely a yield game; your biggest expense is drilling your wells, so being able to get more power out of each of those wells is the real name of the game,” the CEO said.
“That’s a standard oil and gas practice. We’re doing the same thing. We want to get that cost down to as little as possible.”
The Paralana play, and how carbon capture is involved
While the company also has an interest in its Flinders West site, it’s Paralana that Puckridge said had “big potential”.
If it was established, he reckons the plant would have a 37-year lifespan. While active, it would be a “backbone” for baseload power in the state, and – considering its proximity to the border – be an export market to New South Wales.
It could also incorporate a technology that’s fast being held up as a clean energy silver bullet: carbon capture and storage.
In October 2024, Santos’ $335 million SA carbon capture and storage project at Moomba came online. The facility captures carbon dioxide as a by-product of gas production and stores it underground in depleted gas wells.
As Puckridge explains, the CCS method is similar to what geothermal experts do: subsurface reservoir mapping.
He said his proposed method sounded “too good to be true, but it’s actually not”. Essentially, it involves liquifying carbon that would otherwise be stored underground as a gas and used to stimulate the hot rocks to create the steam and thus electricity.
“We’re introducing our own fluids, but a far more efficient conduit or geo-fluid is actually liquid CO2. Water turns to steam at 100 degrees Celsius right? CO2 turns to gas and goes supercritical at 34 degrees,” he said.
“A more reactive geofluid like CO2 instead of H2O is optimised to those lower heats like we have in our Flinders West project.
“It’s a new way of looking at things. It’s gone beyond a science project and it’s starting to be adopted. I wouldn’t go as far as saying no one’s heard of it, but it’s not mainstream yet.”
Where’s the appetite?
Earth’s Energy said it’s raised $6 million so far, and has spent about a third of that, but it’ll take more to get this type of project off the ground.
InDaily asked Energy and Mining Minister Tom Koutsantonis what he thought of geothermal’s potential generally, especially in light of the government shelving its $600 million green hydrogen project after the Whyalla Steelworks collapsed.
“South Australia has always been an ideal place for prospective geothermal projects,” he said.
“We have a robust regulatory process that facilitates industry development of geothermal projects in South Australia, which sits within our Energy Resources Act 2000.
“The Government remains supportive of these projects as potential sources of clean energy and industrial heat and will continue our facilitatory role.”
Puckridge thinks backing South Australian geothermal, especially now that hydrogen has been shelved, is a no-brainer and is cheaper too.
“Hydrogen via electrolysis currently operates at a levelized cost of energy (LCOE) between $120–$180 per MWh, whereas enhanced geothermal systems, like those we aim to develop, have a long-term estimated LCOE target of around $50 per MWh,” he said.
“South Australia’s well-documented heat anomaly is globally recognized, and the pioneering efforts in enhanced geothermal systems at Paralana and the Cooper Basin 14 years ago provide the state with a significant head start.
“South Australia has all the right ingredients: talent, projects, and infrastructure. The key missing piece is a renewed commitment from state and federal governments to support companies like EE1 in re-entering the exploration and development phases – just as they did last time.”
In saying that, Puckridge said he already felt supported in his endeavour to get the two projects off the ground.
“South Australia remains one of the most pro-business jurisdictions in the country, and the Department for Energy and Mining exemplifies that. The department’s deep knowledge of geothermal project development is not only a point of pride for South Australia but also a strong reassurance for companies like EE1,” Puckridge said.
“If any state is going to successfully commercialise geothermal power, South Australia is the most likely to be the first – thanks in large part to the dedicated professionals within DEM.”
