Challenges and Opportunities of Geothermal Exploration and Development in the Western Branch of the East Africa Rift Valley

Abstract

In this paper we present the challenges and opportunities of geothermal exploration and development in the Western Branch (WB) of the East Africa Rift Valley (EARV). The main challenges include inadequate data especially across the borders on shared resources, inadequate and predictable funding, inappropriate exploration philosophy and conceptual modelling because of the unique geology, volcanic activity and structural setting. The models from other regions cannot be applied directly to evaluating the geothermal potential of the WB rift. The complex interconnection between young faults and tectonically activated older fracture systems due to kinematic extension of the Somalian plate causes heterogeneity and anisotropy which determines fluid movement and targets for geothermal exploration and production wells. Drilling shallow wells or targeting areas of hot springs might therefore be completely misleading and the results might not be meaningful in evaluating the geothermal potential. The best targets for drilling geothermal production wells might be on the deep fractures in the basement rocks that are aligned with the old tectonically activated fractures in the vicinity of a heat source which may be associated with the interpreted aligned melt zones. Opportunities therefore exist for research, data acquisition and interpretation, exploration drilling and development of the geothermal resources for direct uses, power generation and geothermal tourism.