Geothermal Energy Australia: How It Works and Future Potential

Beneath your feet lies one of the planet's most stable energy sources: heat. The global geothermal industry converts that underground warmth into electricity and heating, operating in over 30 countries and supplying around 14 gigawatts of capacity worldwide. Unlike solar and wind, geothermal plants run 24 hours a day, offering the reliability that energy grids crave. Australia has barely scratched the surface of its geothermal resources, but the technology is advancing fast and investment is flowing in.

How geothermal energy works

Geothermal power plants drill deep into the Earth's crust where rock temperatures reach 150 degrees Celsius or hotter. Hot water and steam trapped in underground reservoirs are brought to the surface through wells. That steam drives turbines connected to generators, producing electricity. The cooled water is typically injected back into the ground to maintain reservoir pressure and heat, creating a renewable cycle. In colder climates, the same heat pumps warm buildings directly.

The technology is proven. Iceland generates nearly 30 per cent of its electricity from geothermal sources. New Zealand, the Philippines, Indonesia, and Kenya all rely heavily on it. What changes across regions is geology: some places have shallow, accessible heat; others require drilling several kilometres deep.

Why Australia's opportunity is huge but underdeveloped

Australia sits atop enormous geothermal resources, particularly across South Australia, Western Australia, and parts of Queensland. The country has vast areas of hot dry rock (HDR) and enhanced geothermal systems (EGS), where engineers fracture rock at depth to create artificial reservoirs. Studies indicate Australia could theoretically generate tens of gigawatts from geothermal alone. Yet today, Australia produces virtually no geothermal electricity.

The barrier is not geology but economics and timing. Drilling is expensive; early-stage projects require patient capital. Governments in Iceland and New Zealand invested decades ago when alternatives were scarce. Australia's coal abundance made geothermal seem unnecessary until recently. Now, as the energy transition accelerates and coal plants retire, Australian companies and investors are funding pilot projects in the hot sedimentary aquifers of the Cooper Basin and the granite formations of the Adelaide Geosyncline.

The global market and technology shift

Worldwide investment in geothermal nearly doubled between 2015 and 2023. Costs are falling as drilling techniques improve and modular systems become scalable. Enhanced geothermal systems, which artificially create permeability in hot rock where natural reservoirs do not exist, are moving from laboratory to commercial pilot stage in countries including Australia, the United States, and the United Kingdom.

The International Energy Agency projects geothermal capacity could triple by 2050 if policy support strengthens. Most growth will occur in developing nations near tectonic activity, but unconventional geothermal in stable continental crust (where Australia sits) is gaining traction as a dispatchable renewable.

What it means for Australia

Geothermal energy fits a critical gap in Australia's energy puzzle. Solar and wind are cheap but intermittent; coal is reliable but carbon-intensive and closing. Geothermal offers baseload renewable power from a small physical footprint, important in a continent where water is scarce and land competition is fierce. Success in geothermal would reduce Australia's reliance on battery storage and gas peaker plants, lowering grid costs and emissions.

For regional Australia, geothermal offers economic renewal. Projects create long-term jobs in remote areas and diversify economies dependent on fossil fuels. South Australia and Queensland, where pilot plants are advancing, could become centres of geothermal expertise and manufacturing.

Globally, Australia's development of EGS technology in a non-volcanic setting could yield knowledge valuable to Europe, North America, and other developed nations facing similar geology. That expertise translates to exports and intellectual property.

The bottom line

Geothermal energy is not new, but its application in Australia is. The global industry is scaling proven technology; Australia possesses the geology and now the investment interest. Success is not guaranteed. Drilling remains risky and capital-intensive. But if pilot projects demonstrate reliable, cost-competitive geothermal in Australia's conditions, the nation could unlock a substantial source of dispatchable renewable power while exporting technical solutions to a world hungry for reliable clean energy.

This article was compiled by AI and screened before publishing. See our editorial standards.