Huenges E, Ledru P. Geothermal energy systems: Exploration, development, and utilization. Goedhart ML, Booth PW. Shallower magnetic sources were delineated using the Euler deconvolution method. These conditions are commonly found in most parts of the world and may account for the increase in global low-enthalpy geothermal exploration (for more details refer to Huenges and Ledru2). 2 M. Hafner et al., Energy in Africa, Springer, Briefs in Energy, page 47. Woodford A, Chevallier L. Hydrogeology of the Main Karoo Basin: Current knowledge and future research needs. [ Links ], 48. We have all experienced the enormous strength from ocean waves. Port Elizabeth: Nelson Mandela Metropolitan University; 2017. Coal is one of the most environmentally detrimental types of fuel, for example. We correlated these findings against hydro/geological and tectonic controls to find prospective target regions for investigating geothermal energy development. It is generated and stored in the earth and can be captured from hot water springs or reservoirs located near the surface. INTRODUCTION South Africa … There is also a strong correlation between high geothermal gradients and the outcrop pattern of highly radiogenic plutonic rocks, particularly where these are overlain by volcano-sedimentary sequences (Figure 4). Hydrogeological properties throughout the URG are highly complicated10; however, the average groundwater yield rate as measured around geothermal sites and at a depth of ca 2 km is approximately 0.1 L/s.11 An average 5 MW low-enthalpy geothermal plant in the URG produces from reservoir temperatures of about 130 °C at an average depth of 3.5-4.5 km and production flow rates of 40-130 L/s.11 Heated water is typically used to run an Organic Rankine Cycle generation system with excess hot water diverted to provide household heating. Johannesburg: Geological Society of South Africa; 2013. p. 7. http://nora.nerc.ac.uk/503375/. [ Links ], 52. S Afr J Geol. It is also essential to shift away from the other, less sustainable power sources currently in use. A tale of two tectonic terranes. Eglington BM. [ Links ], 35. Our results also highlight that high heat flow is not only restricted to off-craton regions. Olivier J, Venter JS, Jonker CZ. 2016;4(2):25-33. http://www.hrpub.org/journals/article_info.php?aid=5013. Hicks N, Davids S, Beck B, Green A. J Afr Earth Sci. For hot springs with only surface temperature information, we estimated circulation depths of ca 2-5 km, which we inferred from shallow geophysical investigations39,40, surrounding heat flow measurements and from deep borehole temperature data41. A D3 shear zone in the Margate Terrane and its implications for regional deformation in the Natal Metamorphic Province (South Africa). Zones near deep cratonic discontinuities also exhibit elevated geothermal gradients, which is especially noticeable along the Colesberg, Thabazimbi-Murchison and Makonjwa Lineaments. The MyPond Hotel in Port Alfred, Eastern Cape, has become the first installation in South Africa and, quite possibly, in Africa, to use geothermal energy for heating and cooling of the building. [ Links ], 37. Nemangwele F. Radon in the Cango Caves [MSc thesis]. [ Links ], 44. Uranium and thorium contents of Archaean granitoids from the Barberton Mountain Land, South Africa. Dhansay T, Brandl G, De Wit MJ. Tectonophysics. 1954;67(9):664. http://dx.doi.org/10.1088/0370-1301/67/9/302. The South African government has a Working for Energy Programme that aims to process biomass energy for various applications. Within the generation plant, the heated geothermal fluid enters a heat-exchange mechanism under pressure and interacts with a second organic fluid that has a much lower boiling point. Rock physics & phase relations: A handbook of physical constants. S Afr J Geol. [ Links ], 45. 2011;37(4):427-436. http://dx.doi.org/10.4314/wsa.v37i4.1. Tectonophysics. Cham, Switzerland: Springer International Publishing; 2016. http://dx.doi.org/10.1007/978-3-319-40859-0. 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. This is great news for South Africa, which has been lagging behind other countries in Africa and the rest of the world in terms of geothermal development. hot springs located in the Limpopo Belt use a fracture network that was largely created during the Palaeoproterozoic and which underwent reactivation several times, including during more recent Mesozoic uplift.30. 1969;2:445-448. 1979;25(3):219-226. http://dx.doi.org/10.1016/0009-2541(79)90143-8. The depths of the potential heat sources were computed from the radially averaged power spectrum of airborne magnetic data. In: Ahrens T, editor. Robb LJ, Davis DW, Kamo SL, Meyer FM. Origin and evolution of the Cape Mountains and Karoo Basin. Pretoria: Catalogue of South African Lithostratigraphic Units; 2009. p. 13. Bullard EC. However, geothermal energy does not form part of South Africa's future renewable energy scenario. The impact of financial incentives in South Africa is also noticeable with the Renewable Energy Independent Power Producer Procurement Programme, which has resulted in the cost of wind and solar being reduced by 46% and 71%, respectively.1 Including geothermal in this programme could potentially accelerate further research and development and may result in geothermal being added to South Africa's future energy mix. 1949;52(1):231-264. Viola G, Kounov A, Andreoli MA, Mattila J. Brittle tectonic evolution along the western margin of South Africa: More than 500Myr of continued reactivation. Stober I, Bucher K. Hydraulic and hydrochemical properties of deep sedimentary reservoirs of the Upper Rhine Graben, Europe. The RSDC will be at the center of Djibouti’s ambitious geothermal dreams of using geothermal energy to fully supply its domestic market and become a de facto power exporter. In general, a geothermal fluid is circulated through a porous fractured reservoir in a targeted high heat producing plutonic assembly. Our services are designed to ensure maximum yield, optimum operational efficiency and reduced cost through maintenance downtime. [ Links ], 9. J Geol. 2012;115(1):47-64. http://dx.doi.org/10.2113/gssajg.115.1.47. [ Links ], 22. TT577. ‘Geothermal energy is the future’ In Kenya, the Olkaria geothermal power plants operate in the Rift Valley, 105 km northwest of the capital, Nairobi. [ Links ], 55. and D.C. reviewed the final manuscript. Investors need to design operationally efficient plants to ensure the expected yield delivery. Characterization of Aliwal North Hotspring in the Eastern Cape Province of South Africa, using magnetic, electromagnetic and radiometric methods. New insights from borehole KWV-1 (Eastern Cape, South Africa). The vast geothermal potential in the region, combined with the benefits of this energy resource, was the reason for the initiation of a funding programme focussed on the market development in East Africa: the Geothermal … Energy Procedia. 3 L. Dutiro, The Power of the unknown: Geothermal energy in Zimbabwe, The Chronicle published 11 June 2019. Archean granite-gneisses around Mombela and Johannesburg; and Palaeoproterozoic Bushveld felsic rocks) and overlying volcano-sedimentary basin sequences that exhibit their own high heat producing signatures (e.g. [ Links ], 57. Geothermal power has the potential to help mitigate global warming if widely deployed in place of fossil fuels. Heat flow and heat production in the Namaqua mobile belt, South Africa. 2014;4(12):43-58. http://dx.doi.org/10.9790/3021-041203043058. 1963;272(1349):207-230. http://dx.doi.org/10.1098/rspa.1963.0050. ... but fast-track South Africa’s energy transition. For East Africa at least, experts think geothermal energy is the answer. Submit. Walraven F, Kleeman GJ, Allsopp HL. 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. Continental breakup and the development of post-Paleozoic sedimentary basins around southern Africa. 1 Africa’s Renewable Future, The Path to Sustainable Growth, International Renewable Energy Agency,2013. Agemar T, Weber J, Schulz R. Deep geothermal energy production in Germany. Heat flow anomaly in Lesotho: Implications for the southern boundary of the Kaapvaal craton. The results of the geothermal gradient calculations are summarised in Figure 3. 2014;63:5200-5210. http://dx.doi.org/10.1016/j.egypro.2014.11.551. Services for investors, banks, EPC's and developers, Services for equipment and component manufacturers, Contact us to find out how we can support you, TÜV SÜD South Africa Real Estate Services, Product quality consulting and certification, Component and plant systems risk assessment, Quality and safety training and qualification, TÜV SÜD Energy and Media Efficiency Standard (EME), Our feasibility and bankability services enable investors and financial institutions to determine accurate energy yields and returns from their investments, We certify to international standards and provide you with a TÜV SÜD certification mark – widely regarded globally as the mark of trust and quality, Our experts participate in national and international standards committees, providing you foresight and insight into new standards developments. Sign up for latest news and event info. P Phys Soc Lond B. [ Links ], 47. Geothermal power is cost effective, reliable, sustainable, and environmentally friendly. [ Links ], 49. Ages of altered granites adjoining the Witwatersrand Basin with implications for the origin of gold and uranium. [ Links ], 16. Using the results of this study, together with high-yielding, shallow groundwater aquifers as a proxy for deeper hydrogeological conditions, and considering factors of successful development in Germany, we may highlight the most promising regions for investigating low-enthalpy geothermal energy development in South Africa (Figure 4). In no particular order, these areas especially include, but are not necessarily restricted to: (1) regions of the Cape Mountains, especially the Syntaxial region; (2) the southern Karoo; (3) the boundary of the Namaqua-Natal Belt and Kaapvaal Craton north of Durban; (4) the Bushveld Basin near the Thabazimbi-Murchison Lineament, north of Johannesburg; (5) the Limpopo Belt. Keywords: geothermometry; tectonics; renewable energy policy, South Africa is the leading carbon emitter in Africa and has one of the highest rates of emissions of nations in the world.1 This status can be linked to South Africa's vast coal resources, which are an important contributor to the local mining sector and also account for more than 80% of South Africa's energy generation.1 South Africa intends to reduce its carbon emissions by producing about 40% of the country's total energy through renewable sources by 2030.1 This goal will be achieved mostly through solar-, wind- and hydro-generated forms of energy and largely accelerated by a Renewable Energy Independent Power Producer Procurement Programme, which has attracted considerable private-sector investment.1 Renewable energy alone will not meet South Africa's growing energy demands and therefore the country will also consider additional large-scale coal-fired energy, nuclear energy and energy produced from shale gas.1, Low-enthalpy geothermal energy is becoming increasingly popular around the world.2 This popularity is largely because it requires geothermal gradients as low as ca 40 °C/km, which may be found in many global settings. 2010;6(7):1-10. http://pixelrauschen.de/wbmp/media/map06/map_06_07.pdf. There is, currently, no large-scale geothermal production in South Africa, since coal is abundant and relatively cheap, supplying the largest part of the country’s energy requirements. Geophys Res Lett. Evaluation for harnessing low-enthalpy geothermal energy in South Africa based on a model pilot plant in the Limpopo Mobile Belt T Dhansay 2012! Recognizing, correctly evaluating and incorporating technical requirements into the plant design is the key to success. In South Africa, the hotspot pushes the crust upwards, generating the distinctive landscape, which consists mostly of tablelands more than one kilometre above sea level, the researchers say. Tectonophysics. uranium and potassium) which are overlain by a thick and insulating volcano/sedimentary sequence. Investors need to design operationally efficient plants to ensure the expected yield delivery. In this study, we aimed to elaborate on potentially viable geothermal regions of South Africa. Geothermal energy is baseload power. We also correlated these results with high heat producing plutonic and volcano-sedimentary rocks, and established underlying tectonic influences using regional seismicity. These on-craton regions also have high heat producing plutonic rocks (e.g. Heat flow in the Witwatersrand Basin and environs and its significance for the South African shield geotherm and lithosphere thickness. Investigation of CO2 storage potential of the Durban Basin in South Africa. 5) Ocean Energy. There is approximately 30 MW of installed low-enthalpy geothermal capacity within the URG with exploration and development continuing to increase.11, Geological controls on heat flow in South Africa. The average geothermal gradient throughout the URG is ca 35-45 °C/km with high heat flow evident from numerous hot springs. Optimal utilisation of thermal springs in South Africa. Freymark J, Sippel J, Scheck-Wenderoth M, Bär K, Stiller M, Fritsche JG, Kracht M. The deep thermal field of the Upper Rhine Graben. S Afr J Sci. Sissingh W. Comparative tertiary stratigraphy of the Rhine Graben, Bresse Graben and Molasse Basin: Correlation of Alpine foreland events. [ Links ], 46. In general, seismicity related to these deep cratonic discontinuities highlight reactivation associated with a more recent northeast to southwest oriented extension31, which is in agreement with the present-day stress state seen in much of South Africa32. Clauser C, Huenges E. Thermal conductivity of rocks and minerals. S Afr J Geol. S Afr J Geol. Granitoids from the Margate Terrane and their implications for tectono-magmatic models of the Natal Metamorphic Province (South Africa). But harnessing geothermal in South Africa assumes drilling of up to 5km, which is very expensive. Anomalous heat flow and underpinning tectonic influences are also evident with the occurrence of hot springs and higher number of natural on-craton seismic events around these structures (Figure 4d). Regions showing apparent low-enthalpy geothermal energy potential, especially orogenic belts, share several characteristic geological and tectonic similarities. Significantly elevated radiogenic signatures are also evident within the on-craton Archean Witwatersrand and Pongola Basin strata29; and especially from the Palaeoproterozoic Transvaal rocks. Once the geothermal fluid is adequately heated, it is brought to the surface where it enters a generation plant. Thereafter, the organic condensate is returned to the heat exchange system while the cooled geothermal fluid is cycled back into the fractured reservoir (Figure 1). Keywords: geothermal energy, South Africa, geology, electricity generation, binary-cycle ABSTRACT South Africa is located in a geological stable zone. Geothermics. We normalised across the various data sources by calculating the theoretical geothermal gradient and using inverse distance weighting to interpolate these results across South Africa. Our results show a significant link between tectonic features, including those on-craton, and the development of geothermal potential regions.