Geothermal Resource Temperature Characterization

Based on the Geothermal Atlas for Africa , the temperature models at 1 km, 2 km, 3 km, and 4 km depth are part of a 3D conductive thermal model of the African lithosphere.

These layers can be described as follows:

• Model Basis: The layers are derived from a 3D grid with a vertical resolution of 250 meters down to 15 km, constructed using a lithosphere-scale conductive mode. This model incorporates sediment thickness, heat flow, crustal structure, and the depth of the Lithosphere-Asthenosphere Boundary (LAB).
• Calibration: The models are calibrated using a dataset of 923 filtered temperature observations from the British Geological Survey, which were averaged per model grid cell to improve data assimilation.
• Environmental Adjustments:
  • Surface Reference: The ETOPO surface level is used as the top reference level.
  • Magmatic Areas: Magmatic areas have been treated as loci of elevated heat production at a depth range of 3 to 8 km, resulting in temperatures exceeding 200°C at 2 km depth.
• Application: These depth-specific temperature grids serve as primary inputs for assessing the technical performance of geothermal production scenarios across Africa, including direct heating, chilling, and power production (ORC).