South Africa's geothermal energy hotspots inferred from subsurface temperature and geology

Authors

  • Taufeeq Dhansay 1. Council for Geoscience, Bellville, South Africa 2. Africa Earth Observatory Network – Earth Science Stewardship Research Institute, Nelson Mandela University, Port Elizabeth, South Africa
  • Chiedza Musekiwa Council for Geoscience, Bellville, South Africa
  • Thakane Ntholi Council for Geoscience, Bellville, South Africa
  • Luc Chevallier Council for Geoscience, Bellville, South Africa
  • Doug Cole Council for Geoscience, Bellville, South Africa
  • Maarten J. de Wit

DOI:

https://doi.org/10.17159/sajs.2017/20170092

Keywords:

geothermometry, tectonics, renewable energy policy

Abstract

South Africa intends to mitigate its carbon emissions by developing renewable energy from solar, wind and hydro, and investigating alternative energy sources such as natural gas and nuclear. Low-enthalpy geothermal energy is becoming increasingly popular around the world, largely as a result of technological advances that have enabled energy to be harnessed from relatively low temperature sources. However, geothermal energy does not form part of South Africa’s future renewable energy scenario. This omission may be related to insufficient regional analysis of potentially viable geothermal zones across the country. We considered existing subsurface temperature and heat flow measurements and performed solute-based hydrochemical geothermometry to determine potentially anomalous geothermal gradients that could signify underlying low-enthalpy geothermal energy resources. We correlated these findings against hydro/geological and tectonic controls to find prospective target regions for investigating geothermal energy development. Our results show a significant link between tectonic features, including those on-craton, and the development of geothermal potential regions. In addition, potential regions in South Africa share similarities with other locations that have successfully harnessed low-enthalpy geothermal energy. South Africa may therefore have a realistic chance of developing geothermal energy, but will still need additional research and development, including new temperature measurements, and structural, hydrogeological and economic investigations.

Significance: 
  • The regional low-enthalpy geothermal energy potential of South Africa should be further researched for consideration of low-enthalpy geothermal energy as a renewable energy option.

Published

2017-11-29

Issue

Section

Research Article

How to Cite

Dhansay, T., Musekiwa, C., Ntholi, T., Chevallier, L., Cole, D., & de Wit, M. J. (2017). South Africa’s geothermal energy hotspots inferred from subsurface temperature and geology. South African Journal of Science, 113(11/12), 7. https://doi.org/10.17159/sajs.2017/20170092
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