Spotlight on South Africa: An update on research into geothermal energy
Potential areas for geothermal energy production in South Africa
In the past, little attention was paid to research into geothermal energy in South Africa. This was because of the country’s stable geology and the lack of volcanic activity in the study area. In this report, Dr Ernest Tshibalo summarizes the latest research on the potential areas for geothermal energy production. These areas include the Tshipise hot spring area in Limpopo Province and an area in the southern part of the Karoo Basin in the Eastern Cape Province.
Potential areas for Geothermal Energy production
Tshipise hot spring in Limpopo Province
The Council for Geosciences, a unit of the Department of Mineral Resources and Energy (DMRE) in South Africa is investigating the potential of geothermal energy as an affordable, reliable, and renewable energy for direct heating of commercial and residential buildings. The research includes the use of geothermal energy for electricity production, distributed heating and cooling applications and the augmentation of various industrial processes (DMRE, 2020/21).
One of the most promising areas for drilling for viable geothermal energy sources is in the vicinity of a thermal spring called Tshipise. This is located in Limpopo Province in the far northern part of South Africa close to the border with Zimbabwe. This spring has a temperature of 58ºC and a flow rate of 10 l.s-1. The Council for Geosciences (CGS) has sought to understand the relationship between geothermal fluid flow paths and the main geological structures in the area of this hot spring in Limpopo Province. Figure 1 shows the preliminary conceptual model of the Tshipise geothermal prospect area. Magnetotelluric (MT) data acquired in 2019 clearly delineated the boundary between the Karoo succession and the supracrustal rocks of the Beit Bridge Complex. The MT data delineated anomalous zones near the Tshipise spring which may be good target for further exploration. In this area, the reservoir was estimated to be 5 km below the surface. (DMRE,2020/21).
Karoo Basin in Eastern Cape, South Africa
The Karoo basin is an area of 700 000 km² and a basin fill of more than 5000 m of siliciclastic rocks. Campbell et. al., (2016) identified the area as a promising target for future enhanced geothermal system (EGS), resource exploration, development and production. Data obtained from a deep borehole (KWV-1) drilled in 2015 within the framework of the research programme KARIN (Karoo Research Initiative) gave promising results of geothermal energy in South Africa. At greater than 3000m depths, EGS reservoirs were found with temperature above 100ºC.
Figure 2 shows the Geological map of the Karoo Basin indicating the location of borehole KWV-1, Stratigraphic reference sections 1-3, and the potential resource area. Karoo Transect A-C highlight the layer cake stratigraphy of the Karoo Basin with dolerite sills and dykes and location of borehole KWV-1.
CGS geologists recommend that future studies should be conducted in the area and that this should focus on the hydraulic conductivity of the fractures and the influence of dykes and sills in the deep aquifers of the Karoo Basin (Campbell et al. (2016, 16).
In South Africa, the use of deep geothermal energy has not been included in any renewable programme in the country. The country is in transition to move from coal as a source of energy to solar, wind, hydro and gas. However, current research in geothermal energy is promising. Researchers in the field need more support for geothermal exploration, which is expensive. Researchers from the Council of Geosciences, University of South Africa (Unisa) and overseas institutions are conducting research in the field.
The author wishes to acknowledge Prof Jana Olivier (Unisa) for reading and editing the short report.
Campbell, S.A., Mielke, P., and Gotz, A.E.: Geothermal Energy from the Main Karoo Basin? New insights from borehole KWV-1 (Eastern Cape, South Africa), Geotherm Energy, 4:9 (2016).
Republic of South Africa. Department: Mineral Resources and Energy (DMRE): Council for Geosciences (CGS) Annual Report (2020/21) Online:
https://www.geoscience.org.za/images/AnnualReports/AR2021-English.pdf/ Accessed 22 September 2022.
Dr Azwindini Ernest Tshibalo
Department of Environmental Sciences
University of South Africa
Figure 1. The preliminary conceptual model of the Tshipise geothermal prospect area. Source: Council for Geosciences 2020/21, 62
Figure 2. Geological map of the Karoo Basin. Source: Campbell et al (2016, 4).