Authored by Wilfried Bero and received contributions from Dr Rita Okoroafor (PhD)
Kenya is only a few months away from entering the 1 GW geothermal club in terms of installed capacity. Could geothermal energy also play a significant role in South Africa?
A Different Geological Context
Kenya benefits from the East African Rift System, one of the most prolific onshore zones in the world when it comes to geothermal (the EARS, as discussed in our previous article).
South Africa, in contrast, does not sit on a tectonic plate boundary and lacks a widespread high-temperature geothermal gradient. To date, no high-enthalpy geothermal zones have been proven to exist without a magmatic heat source, as found in countries located along the EARS. As a result, large-scale power generation from geothermal is more limited. However, this geological difference should not be interpreted as a lack of opportunity.
South Africa still holds a serious potential for Geothermal exploitation. Here is why:
The in-situ geothermal potential matters. So does the local energy demand. What matters most is matching the two: can the geothermal potential meet the local energy demand?
South Africa experiences marked seasonal variations, where mid-June winter is a common phenomenon. Winters in Johannesburg and the interior plateau are cold, with frost and snow in some regions, as observed this year, 2025. These weather conditions create a need for district heating, not only for households and offices, but also for industrial use.
In that respect, South Africa shares similarities with some European countries, such as France or Germany, where roughly 50% of final energy consumption is allocated to thermal energy (heating and cooling). South Africa’s energy transition must also decarbonise the thermal energy supply.
Low-to-medium enthalpy geothermal systems have been reported with surface manifestations characterised by hot springs in different regions, such as the Limpopo Belt, Western Cape, or to the North of Johannesburg. Siloam Hot Spring (Limpopo) offers surface temperatures of up to 67°C. The heat source is not magmatic, as with Kenya and Ethiopia, but rather from radiogenic granitic rocks. The latter is often faulted and fractured, providing the pathways for heated groundwater circulation.
The existence of hot springs indicates that an underlying energy resource remains untapped.
In some regions, such as the Western Cape, Limpopo Belt, or KwaZulu-Natal, low-to-medium enthalpy resources may support binary cycle (ORC) power plants. These smaller-scale units can serve off-grid areas or be integrated into hybrid renewable systems. Geothermal heat can supply district heating systems, support industrial processes, or heat greenhouses and aquaculture farms.
A national exploration strategy could assess how the resource can be exploited for direct use, electricity production, or even mineral extraction as a byproduct. Geothermal could thus become a key pillar supporting the national energy transition goals.
Brine Mineral Extraction: the geothermal ultimate quiet power:
Geothermal energy is often associated with spectacular geological manifestations, such as the lava lake of Mount Nyiragongo in the DRC, the Afar Depression in Ethiopia, or the active fumaroles of the Kenyan Rift Valley. Aside from its striking manifestations, geothermal energy holds another kind of power that is quiet, steady, and incredibly versatile. Even in regions with no visible volcanic activity, where surface expression is limited to hot springs (often used for spas or leisure), geothermal energy can still deliver substantial value: Geothermal Mineral Extraction.
As interest grows in the co-production of lithium, rare earth elements, and silica from geothermal brines, South Africa could explore synergies between its geothermal energy sector and its strong mining sector, especially in the context of the global energy transition.
The UK and Germany show that geothermal can be viable and strategic, even in the absence of volcanic activity.
UK, Cornwall:
Deep drilling by Geothermal Engineering Ltd (GEL) into radiogenic granite (2.5 to 5 km depth) has confirmed temperatures suitable for electricity generation (180°C) and direct-use heating (source). In parallel, Cornish Lithium Ltd is exploring the geothermal brines in the same region as a potential source of lithium, leached from granite over geological time.
Germany, Landau:
In Germany, Vulcan Energy’s Zero Carbon Lithium™ project taps geothermal brine from Permo-Triassic sandstones. These brines, though hosted in sedimentary rock, owe their lithium content to long-term interaction with the granitic basement (source).
The two above examples prove that granite is often the silent architect behind both heat and minerals.
What About South Africa?
South Africa may not sit on a tectonic plate boundary; nonetheless, it sits on some of the oldest and most heat-producing granites on Earth. Regions like the Limpopo Belt, Namaqua-Natal Mobile Belt, and part of the Karoo, granites contain high concentrations of radiogenic elements, as suggested by the hot springs pointing the way.
While South Africa may lack the geysers and lava flows that often define geothermal hotspots, it possesses geological conditions comparable to those of Cornwall or the Upper Rhine Graben. As global demand for lithium continues to grow, South Africa has compelling reasons to explore its geothermal systems more thoroughly, for both sustainable energy and critical mineral supply.
Join ACBA’s GeoStream Program – Drive Africa’s Geothermal Future
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