Geothermal Energy in Botswana

  • Botswana is fringed on the east by the Zimbabwe Craton and the south by the Kaapvaal Craton with Limpopo Orogenic Belt in between. In the southwest is the Kalahari Suture Zone (KSZ) which is a large scale (~400km x <50km) intrusive feature linked to the Kheis Orogenic Belt that extends into South Africa. Adjacent to the northwest Okavango (Graben) Rift Zone (ORZ), the Ghanzi-Chobe fold belt (with high geothermal gradients) runs up to the Kasane Hot Springs and into Zimbabwe. Orogenic fold belts and intrusive features provide potential heat pathways for Geothermal Energy consideration;
  • The KSZ was formed in a rifted environment along the cratonic margin where magma from plumes were channelled up through fault systems into the sedimentary basin. Dyke-sill networks were formed with hydrothermal mineralisations that brought significant heat flux closer to the surface during deposition. After geophysical survey work, early exploration drilling for large ore deposits is ongoing now and geothermal gradient data will help determine if active heat resources are present;
  • Further heat flux density exploration in these areas is necessary to develop opportunities, but the types of geology in Botswana have been seen in other successful geothermal locations;
  • Clean, environmentally sustainable renewable Geothermal Energy would be possible thanks to modern, low and medium enthalpy Binary ORC power generation solutions. Good geoscience tools are available to help incrementally explore and de-risk the areas of potentially suitable heat energy sources before more expensive drilling is required;
  • Very attractive Levelised Cost of Electricity (LCOE) is commercially feasible for some developments to help improve electrification, reduce reliance on aging coal fired power plants and electricity imports from South Africa, reduce energy poverty, and increase grid resilience for Botswana.

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