THE LEADER VOLUME 20 • NUMBER 8
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Mining & geothermal synergies
A recent article by Dr Marit Brommer, CEO and Dr Helen Robinson, Global R & D Manager, at the International Geothermal Association, delves into the topic of geothermal power and mining being natural allies.
They argue that this is more than just one sector borrowing from another.“ Geothermal and mining are natural allies, with deep technological overlaps, mutual decarbonisation goals, and even co-located opportunities. What’ s more, even after a mine closes, it can offer new geothermal life through mine water heating- an emerging approach to district-scale, clean heat systems. It’ s time to connect the dots- and co-develop a shared future.”
Brommer and Robinson add that this alliance is not new on African soil.“ Few know that the continent’ s first geothermal power plant was built not in Kenya’ s Rift Valley, but in the copper- and tinrich Katanga Province of the Democratic Republic of Congo. In 1952, a 250 kW binary geothermal plant at Kiabukwa was developed to power tin mining operations- marking one of the earliest examples of mining-geothermal integration anywhere in the world. Engineers leveraged a nearby 91 ° C hot spring, delivering clean energy long before Wairakei came online in New Zealand.”
Today, Africa is rediscovering its geothermal potential, with mining players exploring heat beneath their feet to power the next wave of critical mineral extraction. They cite a number of examples. In South Africa, Gold Fields is assessing geothermal use in the deep Witwatersrand gold mines, where rock temperatures are high and ventilation costs are significant. Cooling and refrigeration- critical for safety- could be supported by geothermal systems that extract and repurpose subsurface heat. In Eritrea, Australian mining company Danakali is exploring the utilisation of geothermal at its Colluli mine to meet operational demands in this remote, off-grid region. In Namibia, lithium developer Lepedico is exploring geothermal energy to reduce fossil reliance.
Mining operations, often remote and energyintensive, are under pressure to reduce emissions. Geothermal offers a solution: reliable, on-site, lowemission power.“ A standout case is the Lihir gold mine in Papua New Guinea, which tapped into geothermal reservoirs of 240 – 300 ° C to generate 6 MW of clean power in 2003. Today, that has grown significantly, supplying about 75 % of the mine’ s electricity, avoiding millions in fuel costs, and dramatically improving its environmental footprint.”
Across Indonesia, Chile, and the western United States, overlaps between geothermal reservoirs and mineral-rich formations are increasingly identified.“ These are not coincidences- hydrothermal alteration, the geological process that forms copper, silver, and gold deposits, also creates the high-temperature environments that enable geothermal power. Where you see hot fluids and alteration zones, you often see both metals and megawatts.”
They also point out that beyond geology, mining and geothermal share core exploration methods: surface mapping, geophysical surveys, geochemical sampling, and 3D modelling.“ These synergies lower costs, speed up discovery, and enable data-sharing ecosystems. For example, the EarthMRI initiative by the US Geological Survey generates nationalscale subsurface datasets that can support both mining and geothermal development.”
A partnership between Seequent and the International Geothermal Association( IGA) is an example they say of working smarter, not harder:“ Seequent’ s geological modelling software was originally designed with mining in mind, but its subsurface software portfolio has application cross industry, including helping shape the future of geothermal projects globally as well. We don’ t need to build parallel systems. We need to build shared ones.”
The authors also discuss legacy mines, as geothermal doesn’ t end when a mine shuts down.“ Flooded underground mines- once seen as costly liabilities- are now being reimagined as subsurface thermal batteries. This concept, known as mine water geothermal, is already powering heating networks across Europe.”
Finally, they point out that geothermal’ s evolution continues.“ Enhanced Geothermal Systems( EGS)- engineered reservoirs in hot dry rock- allow geothermal to flourish even outside traditional hydrothermal zones. This is particularly promising for mining sites that already have deep wells or suitable geology. In Nevada, Fervo Energy is using EGS to power Google’ s remote data centres. Similar models could easily be applied to mining operations looking to go off-grid.”
Meanwhile, the US Department of Energy’ s GEODE initiative is investigating how geothermal fluids can become sources of rare earth elements and critical minerals, turning geothermal power plants into dual-purpose energy and mining facilities. And large mining firms are investing.
Of course, challenges remain. To truly capitalise on this convergence, Brommer and Robinson argue that the following is needed: integrated licensing for overlapping geothermal and mining tenures; open data platforms for subsurface exploration and resource characterisation; and co-investment strategies for joint geothermalmining projects. Plus, incentives for mine water geothermal planning in closure and reclamation stages & shared curricula and training programs that build dual-sector expertise.
Paul Moore Editorial Director paul @ im-mining. com
International Mining | AUGUST 2025 3